This PDF file contains the front matter associated with SPIE Proceedings Volume 11568, including the Title Page, Copyright information and Table of Contents

In view of the problem of projection distortion in the result of aberration-free point test of off-axis paraboloid mirror, this paper analyzes its formation principle, puts forward a transformation method from the detection coordinate system to the processing coordinate system, according to the mathematical relationship between the two, reconstructs the surface shape of the detection result, realizes the transformation of projection distortion image, and analyzes the error of the transformation result by using the fucial function. It is proved that this method is feasible by using the reconstructed surface results to guide the NC Polishing.

Chromatic confocal displacement sensor is one of non-contact displacement sensors based on optical wavelength displacement modulation. It is also a new photoelectric displacement sensor with high accuracy and stability which used to measure surface topography, distance, thickness and so on. In this paper, a hyperchromatic lens with the measurement range of 1mm is designed by using CODE V optical design software. The mentality of designing of hyperchromatic lens are researched according to the conditions of linear longitudinal chromatic aberration. Meanwhile the importance of image space numerical aperture (NA) and linearity of the longitudinal chromatic aberration to the sensor are clarified. In the final design of hyperchromatic lens, we realized the image space NA of 0.4436 and the linear regression coefficient R² of 0.991 taking into account both linear longitudinal chromatic aberration and image space NA.

Large aperture optical element deformed by its own weight is caused is one of the important considerations when we design the optical system, designing a mirror support solution that reduces the effects of gravity is critical. Traditional methods cannot effectively and intuitively analyze mirror distortion. In this paper, the finite element method and the optical surface fitting with Zernike polynomial are used to optimize the support scheme. These two methods are mutually verified and this method which use two parts is verified by the optimization scheme of the Φ900mm standard spherical mirror. With optimization, the steel belt loading and unloading weight hammer support scheme is finally adopted, and the best solution with Φ705mmin the circumference and each aperture is 55mm on the back of the mirror is obtained. The theoretical mirror surface’s PV and RMS value equal to 7.36nm (1/86λ) and 1.64nm (1/386λ), which is a good basis for guiding production.

In order to complete the detection of small displacements, the principle of grating diffraction interference is used to convert the displacement of the measured target into the change of the light and dark of the fringes after interference. The displacement information is estimated by detecting the change in light intensity. However, this method requires high optical path symmetry and complicated installation. In this regard, by modifying the optical path and using the principle of interference, this article enlarges and visualizes the installation error. Thereby reducing the complexity of installation and adjustment, and improving the accuracy of installation and adjustment.

On the basis of optical theory, the mathematical model of axisymmetric high-order aspherical curve and the curve characteristic parameters related to the locus of aspherical surface are summarized. The non-contact precise measurement and correction of the central deviation of axisymmetric high-order aspherical lens based on autocollimated centering principle and spectral confocal displacement sensing technology are introduced. The methods of measuring the center deviation of aspheric lens with concave and convex surfaces are given. The aspheric measuring device of Trioptics double optical path center deviation measuring instrument is used to measure the axisymmetric high-order aspheric lens, Through several measurements and modifications, the final results meet the requirements of the whole optical system for the optical axis deviation of the axisymmetric high-order aspheric lens. The technology of measuring and correcting the center deviation of high-order aspheric lens with axial symmetry introduced in the paper has high non-contact measuring accuracy, which can guide the adjustment amount and position direction of the coincidence of the axis of symmetry and the axis of mechanical rotation of aspheric lens. It can be widely used in the process of on-line processing, testing and systematic adjustment of aspheric lens and aspheric mirror with different apertures. While ensuring the accuracy of aspheric surface, it can improve the quality of finish grinding process, save a lot of time for polishing process, and play a guiding role in its processing and manufacturing process and high-precision system installation, so as to greatly improve the processing efficiency of axisymmetric high-order aspheric surface and the final optical system installation and adjustment accuracy.

Plasma figuring technologies have been widely used in the processing of silicon-based materials at atmospheric pressure. Previous plasma figuring of silicon based optical surfaces has been undertaken using a radio frequency plasma jet through an Inductively Coupled Plasma (ICP) torch. Microwave plasma is suitable for processing those materials that cannot bear high temperature from the thermal plasma jet. For crystalline quartz (SiO₄) processing, microwave plasma systems employ electrodes to couple the microwaves into the gas; however, the presence of reactive plasma interactions with any electrode surfaces, typically results in electrode degradation. To avoid this degradation, the Surface Wave Launched Microwave Induced Plasma (SWL-MIP) torch design was selected that uses the principal of surface wave launching. The electromagnetic frequency was set to 2.5 GHz for all the experiments. Argon is used as a main carrier gas. Carbon tetrafluoride (CF₄) is used as a secondary gas for the creation of reactive species and consequently enables the material removal of silicon atoms from the substrates. Optical Emission Spectroscopy (OES) characterization confirmed that these parameters led to a plasma jet, which was stable both spatially and temporally. The optimum parameters were used for the material removal experiments of crystal quartz. Finally, a material removal rate of 0.18 mm³/min was achieved with substrate preheating to 200 °C. The maximum surface roughness at the bottom of a measured trench increased from an Sq of 1.5 nm up to a mean average Sq of 3.5 nm.

A new method of transmission efficiency and uniformity measurement for optical fiber image transmission component(OFITC) in visible band is proposed. The ray which emitted from the light source is received by a brightness sensor chip, which can convert the rough brightness into the visual brightness of specific area by weighted calculation. The visual brightness matrices of the designated area before and after placing the OFITC are named S1 and S2, respectively. After filtering, the transmission efficiency of OFITC is the quotient of the average values of S1 and S2. In order to calculate the light uniformity, S2 is divided into four parts which are circles or rings. The average of variances of these parts is defined as the uniformity. The brightness sensor chip required by this method is customized according to the size of optical fiber image transmission element. The experimental results can confirm the validity of this measurement method. At last, criteria for transmission efficiency and uniformity evaluation are proposed, which can greatly reduce the judgment error, improve the testing efficiency and save the cost of detection.

Polarization is steadily attracting attention in machine vision due to its ability to capture the information not readily available in standard color or greyscale camera. In this paper, the degree of polarization image and intensity image are used to calculate the position and posture of stamping parts. First, the degree of polarization image and intensity image were acquired from polarization camera. Canny edge operator is used to filter the polarization degree image to get the edge image. Morphological analysis and connected domain statistics are performed on the edge image, and location holes are extracted from the connected domain according to the geometric characteristics. Combined with the extracted location holes region, the obtained polarization intensity image is segmented by local threshold, and the edge contour of the location hole is extracted and the coordinates of the center point are calculated.

The high-precision measurement of blade profile has always affected the development of domestic aeroengine manufacturing industry. However, the traditional measurements have gradually failed to meet the increasing requirements of blade manufacturing accuracy. Aiming at the problem of detecting the aeroengine blade profile, the AGILITY multi-axis compound measuring machine is used in this paper. A measurement combining contact and noncontact is proposed, the practical test technology of blade is studied. Finally, the feasibility of the method is verified by analyzing the results. A technical scheme for the detection of blade profile of domestic aeroengine is provided.

This paper presents an optical system of continuous zoom objective lens with multi-conjugate distances which can clearly image at multiple working distances. We firstly design a continuous zoom objective lens with a standard working distance, then optimize it with multiple conjugate distances. When the working distance changes, adjust the position of the image sensor accordingly to achieve clear imaging. The final designed optical system has a working distance range from 65mm to 130mm which can realize a continuous magnification range from 0.18× to 2.65×. The objective lens system can match a 1/2-inch image sensor, and the image sensor can move 16mm relative to the lens. The design results show that the MTF curves for each magnification and working distance are close to the diffraction limit and the imaging performance is good for each configuration. Compared with the conventional continuous zoom objective lens with a fixed working distance, the working distance range of the continuous zoom objective lens with multi-conjugate distances is wider and the zoom ratio is further expanded, which can better meet the requirements of different application scenarios.

In view of the problem of projection distortion in the result of aberration-free point test of off-axis paraboloid mirror, this paper analyzes its formation principle, puts forward a transformation method from the detection coordinate system to the processing coordinate system, according to the mathematical relationship between the two, reconstructs the surface shape of the detection result, realizes the transformation of projection distortion image, and analyzes the error of the transformation result by using the fucial function. It is proved that this method is feasible by using the reconstructed surface results to guide the NC Polishing.

Fused silica optical elements have been widely used in high power laser systems because of their good optical and mechanical properties. However, defects such as scratches on the surface/sub-surface will inevitably occur in the process of optical components. It will affect the laser damage threshold. To simulate the effect of the defect on performance of laser radiation, evolution law of the scratches in chemical etching must be predefined. In order to determine the influence of scratch, a surface scratcher used to produce a specific scratches on the surface of the elements, and its morphology was characterized and the damage test was performed. By analyzing the morphology and characteristics of the scratches during chemical processing, and recording their fluorescence effects, it is clear that the width of the scratches increases with the depth of the etching, and the laser damage resistance is gradually improved. At the same time, the initial defects of different characteristics were clarified, the evolution rate in chemical etching was not consistent, and the impact on the ability to resist laser damage was different. In general, scratch defects have severely impaired the resistance of the device to laser damage. When the damage threshold of the component without scratches is about 23J/cm², the damage threshold of the defect location is only less than 5J/cm2. Through targeted chemical treatment processes, you can increase the threshold of most scratch damage to the level of no scratches.

As to the need of low distortion MWIR optical system with high resolution and large width, the initial structure of the coaxial two-mirror and the relay optical system were calculated based on the aberration theory and Gauss’s optical imaging formula. According to the aberration auto-balance optimization of optical design software, the aspheric surface is introduced to correct residual aberration, and the compact requirement of infrared optical system was realized. Focal length 2000mm, F number 3, field of view 3°×0.5°, the operating wave band 3~5μm and 100% cold shied efficiency reached. High imaging quality was realized. The modulation transfer function of the system exceed 0.34 all over the field of view at the Nyquist frequency of 33lp/mm, and the relative distortion below 0.1%.The results of the design revealed the target depth that can be realized by the coaxial two-mirror system and relay optical system. The system can achieved a resolution 3.75m and a width of 26km.

Full aperture polishing (FAP) is the key application process that realizes low damage and ultra-smooth surface in the fabrication of large plane optical element. The polishing pad plays a vital role as a significant part in FAP. When the material of element is removed, the contact surface of pad also appears non-uniform wear, which is detrimental to polishing accuracy and efficiency. In this work, wear density (WD) is proposed to characterize wear uniformity of pad, and relative wear (RW) is used to represent the wear degree. Based on the wear density distribution model, the effect of process parameters on the pad wear is investigated. It is pointed out that when the speed difference between the element and the polishing plate is 0.2r/min to 0.5r/min, the wear track distribution of pad is relatively uniform. Furthermore, the results showed that swing has the greatest influence on the wear non-uniformity, while the traverse velocity is the smallest. In order to reduce the serious local wear, the swing can be increased according to the diameter of the polishing plate. This provides a good guidance for the optimization of FAP process.

Since the central part of laser beam cannot be transmitted through the traditional Cassegrain antenna, thus a large energy loss is caused. To improve the transmission efficiency of traditional Cassegrain antenna, a pair of lenses is designed and set between the laser source and traditional Cassegrain antenna in this paper. The parameters of the pair of lenses and Cassegrain antenna system is determined and the energy distribution after the laser beam passing through the pair of lenses is discussed in detail. Based on three dimensional vector refraction and reflection theory, the ray tracing of the entire communication system and the chart of the transmission efficiency are simulated with MATLAB. From the chart, it can be concluded that proper laser beam shaping can improve the transmission efficiency of the entire communication system up to 100% at the wavelength of 1550 nm under ideal condition. After taking several practical factors such as the reflectivity of the mirror composing the Cassegrain antenna, the transmissivity and chamfering of the pair of lenses and the dispersion of the material into account, the transmission efficiency of the entire system can still be increased to 95.54% at the wavelength of 1550 nm. Compared with designing complex antenna systems, the method presented in this paper is more practical and convenient for optical communication.

The calibration technology of three-dimensional laser scanner for measuring volume of railway tank car were studied and designed. By using the capacity comparison method, the measurement results obtained by using the standard metal gauges with high accuracy were compared with the measurement results obtained by using the three-dimensional laser scanner for measuring volume of railway tank car, and the measurement repeatability and indication error of calibrate three-dimensional laser scanner were calculated. Finally, calibration results of the precision three-dimensional laser scanner for measuring volume of railway tank car were obtained. The technology was scientific and efficient, which can solve the problem of calibration of the three-dimensional laser scanner for measuring volume of railway tank car. It can meet the urgent need of accurate and reliable measurement of the volume of medium and large capacity containers by three-dimensional laser scanning technology in china, and has better social and economic benefits.

Future large aperture telescopes and high contrast imaging systems will often include segment gaps, structural obscurations, along with outer edges which produce diffraction effects that are disadvantageous to high contrast imaging (e.g., for exoplanet detection) or continuous wavefront control across the optical aperture. We present an optimization strategy for several pupil segment topologies for next-generation telescope concepts. Wave propagation results based on diffraction-limited point spread function analyses using Fraunhofer diffraction theory are presented using the Python-based POPPY simulation tool.

Using phase mask technology, the method of online preparation of wire-drawing tower grating (DTG) under single pulse laser was studied. the self-prepared DTG separately tested its breaking strength, the consistency of hundreds of identical gratings (center wavelength and reflectivity), and the temperature response of thousands of gratings in a single fiber. The results show that under the optimal process, the mechanical strength of DTG is not only consistent with the original fiber, but also relatively 6% higher than that of FBG; the isotropic grating at different positions, the center wavelength is stable within 80pm, and the reflectance difference is less than 3dB, and the temperature response consistency is very high. Therefore, the proposed single-pulse laser based on the phase mask to prepare the drawing tower grating can fully meet the requirements of the internet of things for large-capacity, fast response, long-distance, densely distributed fiber sensor network technology.

We measured the nonlinear absorption coefficient of YVO4 using nonlinear transmittance method. The result is: for wavelength of 800nm, YVO4’s nonlinear absorption coefficient is 3.2×10^-3 cm/GW for p polarization and 3.1×10^-3 cm/GW for s polarization; for wavelength of 400nm, YVO4’s nonlinear absorption coefficient is 0.17cm/GW for p polarization and 0.16cm/GW for s polarization.

The unwanted light transmitting through the gap spaces of low fill factor lens array will deteriorate the signal contrast detected by the sensor. The high cost photolithographic techniques and optical coating technology have to be used to deposit a metallic film precisely filling these gap regions, which is only suitable for the lens array on flat substrate. In this paper, we will propose an efficient way for the fabrication of gap-masked lens array on a curved plastic substrate by using the direct diamond turning and spray coating process. The semi-finished lens array (SFLA) on a convex surface is first fabricated by rough cutting with fast tool servo. A paint film layer with mirror surface effect is then formed uniformly by spray coating on the SFLA which has a rotation speed controlled by the computer-numerically controlled (CNC) machine. At last, the lenslet surfaces are uncovered and regenerated by finishing cutting process. Without any reloading or re-position error, this cost-effective method can generate various gap-masked array optics on curved substrate with customized period and grid pattern.

In order to solve the problems such as the high difficulty and low detectable rate of the micro-deformation defects ascribed to steel plate surface deformation, this paper proposes a method of deformation defect analysis via texture collecting. First, carry out image analysis on the working principle of different camera lighting methods on the steel plate surface, and construct an image acquisition system based on the characteristics of bright and dark ground illuminations. According to the diffraction of light occurring on the steel plate surface, use industrial camera to collect the surface texture that is similar to raster to analyze micro-deformation defects. Secondly, carry out grey level transformation against the images collected via histogram equalization method to eliminate the influence of uneven illuminations, smoothen the boundary with morphological processing and eliminate the gray scale change in the striped area via Otsu binarization. Finally, propose three characteristics for the pre-processed image for characteristic extraction according to the gradient information of the image on the pixels and use the improved SVM as a classifier and also the extracted features for the purpose of image dichotomy. We also studied the influence of the eigenvalues on the accuracy of defect detection under different sizes and effective values. According to the experimental results, this method is able to detect micro-deformation defects of steel plate surface quickly and accurately, without relying on sensor to measure depth information of the surface.

Based on the theoretical model of small-tool polishing, this paper studied the influence of polishing parameters on the results of computer controlled optical surfacing. We compared different parameters of the removal function and the tool path and analyzed the residual mid-spatial frequency errors in the polishing process. The simulation results indicated that raster path combined with Gaussian removal function, contributing to high accuracy of PSD1 RMS, but leading to serious peaks of 1D PSD1 curves in some frequency points. In contrast, pseudo-random path combined with flat-topped removal function, resulting in lower accuracy of PSD1 RMS, but could effectively restrain the amplitude of the 1D PSD1 curves. Finally, experimental study was carried out on both of the 610 mm × 440 mm K9 material transmission mirror and 430 mm × 430 mm fused silica plane window, the RMS value of PSD1 converged from 3.72 nm to 1.61 nm, and decreased from 2.30 nm to 1.37 nm, respectively, which demonstrated the correctness of the model.

Close-range photogrammetry, as an important part of non-contact measurement, plays an important role in industrial manufacturing. This paper summarizes the basic principle of digital close-range industrial survey, introduces the structure and function of photogrammetric system, and focuses on the key techniques of photogrammetric technology, including the acquisition of high-quality images, central positioning of landmarks, camera calibration and automation technology, etc. Next has analyzed the current research direction of digital photogrammetry system and its application in different industrial fields. Finally, the demand of digital photogrammetry is summarized in the thesis, and put forward the development direction of close-range photogrammetry in large size and high precision, automation, specialized data analysis, etc.

Fringe reflectometry is a favorite method for 3D measurement of specular surfaces with the advantages of simple structure, low cost and high precision. The traditional reflectometry method is based on the telecentric optical path assumption. When the surface has a large diameter or curvature, this assumption is hard to be guaranteed. In addition, the non-sinusoidal distortion of fringes will also introduce significant phase errors and degrade the measurement accuracy. To avoid these problems, a high precision monoscopic fringe reflection measurement model is proposed based on a reference plane. The relative phase change between the measured surface and the reference plane is used to get the accurate corresponding screen points for each point on camera imaging plane. With these correspondence point pairs, the normal vectors and the 3D geometry can be obtained. To validate the effectiveness of the proposed method, a concave spherical mirror was measured. The peak to valley value of the residue error can reach 0.784μm which demonstrates high accuracy of the method.

The manufacturing technique of aspherical surfaces relies on the assistant optical test design. The paper introduces the typical methods of classic test and null compensation test. Based on the third order spherical theory, the aplanatic expression of classic test and null compensation is derived. In order to realize the aspherical test of large diameter and large relative aperture, and even super large diameter and super large relative aperture. In this paper, the new theory and concept of conjugate correction aspheric test is proposed for the first time. The test is applicable to convex and concave aspheric surface. The principle of conjugate correction test is explained. The basic theory of conjugate correction is established. The analytical mathematical expressions of spherical aberration for three kinds of conjugate correction test configurations are explored. Optical designs of three self-collimating conjugate correction lenses and Offner null test are given. The difference of conjugate correction test is compared with classic test or null compensation test. According to theory analysis, the mathematical expression of conjugate correction aspherical test includes the cases of classic aspheric test and null compensation aspheric test. And the mathematical expression of classic aspheric test and null compensation aspheric test is a special case of the conjugate correction aspheric test.

Aiming at the characteristics of high brittleness, low fracture toughness and difficulty in processing of raw materials for aspheric optical components, a new method of creating optical aspheric surfaces based on two-dimensional ultrasonic elliptical vibration abrasive belt grinding was proposed. In this paper, a new path planning algorithm for machining optical aspheric surfaces by abrasive belt grinding was designed, which took into account the radius compensation of abrasive belt grinding head and the micro displacement of the machining path excited by the ultrasonic vibration in Y and Z directions. And a typical aspheric surface, toric surface, was used to simulate the machining path planning, which proved the effectiveness and correctness of the proposed machining path planning algorithm. This technology will play a positive role in promoting the development of precision machining technology with ultrasonic vibration for aspheric surfaces.

In the view of the problem existing in optical system for airborne pods, the type of optical system suitable for the compact space of airborne pods is analyzed, and the combination of the-three-mirror afocal system and the telephoto system are chosen. In this paper, the method of three-mirror-afocal system design based on primary aberration is explored. The structural parameters are calculated according to primary aberration coefficient. The procedure for calculating initial structural parameters is programmed. Then a three-mirror afocal system is designed with an entrance pupil diameter of 115mm, a field of view of 1.4°×1°, compression ratio of 5 times. The principle of telephoto system is introduced, and two relay optical systems are designed. The results indicate that the design values of the average modulation transfer function (MTF) are 0.43 and 0.57 respectively. The average MTF of dual channel systems are 0.37 and 0.55 respectively after the installation and adjustment. The main optical system and relay system in this paper have high imaging quality, and the modular design can be realized by replacing the relay system. The method of dual channel system can be used for multichannel airborne pods.

Due to the characteristics of large depth, small period and high steepness, phase optical elements with complex structure need to use a small size removal function in magnetorheological processing, and use very small line spacing and step size values when planning the polishing path，so the dwell time matrix is very large, and the dwell time calculation speed is slow; besides, because of the complicated phase optical profile, it is difficult to achieve high-precision convergence of the dwell time. This paper proposes a fast and high-precision numerical iterative dwell time algorithm for complex structure phase optical elements. this paper proposes the concept of the dwell point matrix, which realizes the methods of the FFT convolution multi-core parallel algorithm to calculate the dwell time in the entire iterative calculation process. Also, to achieve high-precision convergence of the dwell time calculation, this paper proposes a calculation rule based on machine dynamic performance matching, when calculating the dwell time, the speed, acceleration, and speed smoothness of the machine were matched with the performance of the magnetorheological machine, which improves the stability of the machine. A large-diameter Continuous Phase Plate (CPP) is processed on a magnetorheological machine. The shape of the CPP contains a random structure of various periods. The initial RMS = 228.07nm, the CPP data matrix size is 2424 × 2424, and the line spacing is 0.6mm, the dwell time is calculated using the algorithm described in this article, the entire calculation process takes only 4.2 seconds, the calculation speed is about 3 times faster than the traditional iterative methods, the CPP residual error RMS converges to 10.2nm; After the CPP processing is completed, the CPP actual residual error RMS is reduced from the original 228.07nm to 15.6nm, and its convergence rate is 93.1%, which shows that the algorithm has high calculation efficiency and convergence accuracy.

The exploration of the optical properties of charged particles is essential for the optical detection of ultrafine particles. In this paper, the complex refractive index model and scattering model of spherical particles are re-established to make them suitable for both electrically neutral particles and charged particles. Taking pure-water droplets and salt-water droplets as examples, the effects of surface charge on the complex refractive index of non-dissipative particles and dissipative particles are discussed. On this basis, the effects of excess surface charge on the optical parameters of droplets, inorganic oxide particles and organic compound particles are discussed with three typical dissipative particles. Furthermore, it is confirmed that the effect of charge on particles with different properties is consistent.

Atmospheric Pressure Plasma Jet (APPJ) is a promising technology for precision machining of optical elements due to its high efficiency, free damage and lower cost, it has been developed as a promising technique for advanced optical fabrication in high energy laser systems, space optics and large telescope projects. Nowadays the challenge faced by the plasma technology application is the effect of plasma temperature on removal rate and surface accuracy. In the plasma processing, the plasma itself not only acts as the supplier of reactive species but also acts as a local heat source. Based on the pure chemical reaction mechanism the material removal rate, the removal rate strongly depends on the workpiece surface temperature, and the temperature fluctuations originating from the plasma jet lead to a nonlinear etching behavior. The thermal effect caused by high temperature and high enthalpy of plasma jet restricts the high-precision machining of optical components. In this paper the heat transfer process between plasma jet and substrate is established and the simulation analysis, experiment research also conducted. Based on the energy balance in the generalized lowtemperature plasma processing, the suitable boundary conditions are selected and the heat transfer model in the jet processing is established. The heat flux density on the surface of the components under different machining conditions is acquired by conducting a steady-state temperature measurement experiment. An iterative method is proposed to fully determine the thermal boundary condition, the heat transfer model between plasma jet and substrate is established. And the heating and removal experimental studies are carried out to verify the proposed heat transfer model and thermal effect on material removal is analyzed for plasma processing.

Large-Aperture Optical Centering Machinery Turning technology has been widely used in precision optical machine assembly. The main principle is to make optical axis and machine axis coincide by maintaining the collimation image and structural end face unchanged when rotating. Structural parts are fabricated precisely after than. This process requires good verticality between the end face of the optical element and its optical axis. A specific method is required to calculate the verticality of the end face and the optical axis. This paper proposed a method based on self-collimated image deviation control and least squares fitting. Combining with an example, numerical calculation is carried out with error analysis. Finally the verticality is 21um which provides reliable data guarantee for the selection of the reference during optical centering fabricating processing.

Diffractive optical elements can simplify the system structure due to their unique negative dispersion properties for imaging systems. It is difficult for single-layer diffractive optical elements (SLDOEs) to maintain high diffraction efficiency over a wide waveband. We propose a design method using optical–digital joint design to reduce the image blur caused by low diffraction efficiency. This method directly and clearly images in the waveband of higher diffraction efficiency, and indirectly images through imaging reconstruction in the waveband of lower diffraction efficiency. A point spread function model considering the effect of roughness on diffraction efficiency during processing is proposed to recovery the blurred image. We design a dual waveband infrared imaging system using SLDOE for 3.7μm~4.8μm and 7.7μm~10μm. The MTF for each field of view at 17 lp/mm are respectively greater than 0.7 and 0.5. The reconstructed image of LWIR is obviously subjectively clearer than the original image, and multiple evaluation function values are better than the original image. The results show that the design method can improve the image blur caused by reduced diffraction efficiency and SLDOEs can be applied to the design of dual waveband infrared imaging systems.

The R2O-SiO2-B2O3 glass has emerged as an important material due to its high performance. Annealing condition has significant effect on the properties of R₂O-SiO₂-B₂O₃ glass. R₂O-SiO₂-B₂O₃ glass has been annealed in different temperature and holding time. The influence of the annealing condition on the properties of R2O-SiO2-B2O3 glass such as hardness, refractive index, and transmissivity were systematically studied. The results indicate that the annealing process can reduce glass hardness and improve refractive index significantly, but enhance transmissivity slightly. The optimal performance of the R₂O-SiO₂-B₂O₃ glass can be obtained under the annealing temperature of 650°C with the holding time of 4h.

A simpler and lower cost Reactive Ion Figuring (RIF) process was demonstrated, combining with flexible film photomasks and an algorithm of masking layers distribution for less iteration. As a novel alternative figuring technology, RIF with parallel removal mode and chemical removal mechanism has showed the actual potential for large segment class figuring, especially in mass production of lightweight optical membrane components. Although diffractive membrane optics has been expected to meet the requirement of large aperture space-based telescopes, the flexible membrane has so different properties from traditional materials that the desired geometrical form is hardly obtained by current ultra-precision surface manufacturing technologies. In this paper, a 300 mm aperture polyimide membrane substrate was figure-corrected by RIF from the initial figure error of 62 nm rms to the final figure error of ~20 nm rms in total effective figuring time of ~4.3 minutes. Film photomask lowered the cost of photomask fabrication down to less than two hundredths of that of quartz photomask fabrication. All distributions of protected regions and removed regions, i.e., the patterns to be fabricated onto film photomasks, were obtained from the transmitted wave-front map just at the start of the entire RIF process. After 2 iterations, it took ~4.3 min to figure this sample and the 20 nm RMS is obtained with a RMS convergence ratio of 3.1.

Smart robot polishing experiments of a reflective mirror are carried on in the paper to verify the pre-filling method. First, pre-filling method is used to simulate the surface figure of a zerodur mirror whose edge is out of the measuring scope of the Zygo interferometer partly in contrast to that of the original one. Second, the polished surface figures with different polishing depths are simulated in the paper to get the relatively right polishing depth of the mirror whose surface figure is processed with the pre-filling method. And at the same time, the polished surface figures with different polishing depths with the unfilled surface figure are also simulated by contrast. Third, smart robot polishing experiment is carried on to verify both the chosen polishing depth and the pre-filling method. Forth, the real surface figure of the mirror after polishing is calibrated. The measuring results show that the surface figure of the mirror after polishing is changed greatly in comparison of that of the mirror before polishing: the surface figure of the mirror before polishing is that the root-meansquare value (RMS value) is about0.374 λ (λ=632.8nm), and the edge is invisible partly, while the RMS value of the surface figure of the mirror after polishing is about0.231 λ, and the edge is visible. The convergence rate of RMS value is 38.2%. The experimental results show that pre-filling method can simulate rightly the surface figure of the aspheric mirror whose edge is out of the measuring scope of the Zygo interferometer.

Lap-MRF, which is considered as a novel flexible finishing method, can produce smooth optical surface. In this paper, the influence mechanism of the optical surface roughness in Lap-MRF is analyzed. The effect of the processing parameters on the optical surface roughness after Lap-MRF is studied by orthogonal experiments. Based on the experimental results, the processing parameters of Lap-MRF are optimized to achieve optical surface with low RMS (Root-Mean-Square) value. At last, a K9 optical surface is finished under the optimal processing parameters and its optical surface roughness is improved to 0.459 n m RMS from 1.669 nm RMS. The results verify that Lap-MRF has great potential in finishing optical surface with high quality.

Spectral domain OCT (SD-OCT) is a branch of Fourier domain OCT (FD-OCT) technology. Thanks to the characteristics of high sensitivity, high precision and non-invasion, SD-OCT can be widely used in clinical medical diagnosis, industrial nondestructive testing and distance measurement. However, one of the main drawbacks of the SD-OCT is the poor light collection efficiency of the fiber probe because the conventional single-mode fiber probe for light collection has very small diameter. In this paper, the multi-mode fiber probe was used for optical delivery and collection, the feasibility of this method has been verified both theoretically and experimentally. Furthermore, the higher efficiency of the light collection was obtained when the multi-mode fiber probe was used in the system. It is especially suitable for small distance and uncooperative target distance measurement.

High-precision cylindrical lens optics are widely used in high-precision equipment, such as high-power laser resonators and long-distance line interferometers. In most instances, this lens required to possess extremely low surface roughness and surface defects. Using dark-field microscopy to detect the surface defects of the cylindrical mirror is simpler than the interferometric, and the cost is lower. In the experiment, we designed a set of image acquisition devices based on the characteristics of the cylindrical mirrors, and used this device to obtain overlapping sub-aperture images of the cylindrical mirrors. According to the overlapping area to solve the relative position relationship of two adjacent sub-apertures, an image stitching algorithm based on defect location is proposed, which realizes the stitching of multiple sub-apertures. The experimental system was used to scan a plano-convex cylindrical mirror with a size of 22mm×22mm and a radius of curvature of 41.34mm. Splicing the obtained sub-aperture images of surface defects. Experiments show that the stitching algorithm has high matching accuracy and strong robustness.

Computer-controlled optical surface forming technology (CCOS) can greatly improve the processing accuracy and processing efficiency of optical mirrors. The most critical problem is the solution of dwell time, which will directly affect the final convergence of the surface shape. it is found through analysis that the solution of the dwell time is a deconvolution process, which is the same as the mathematical model of the Lucy–Richardson algorithm in image restoration technology, so the algorithm can be applied to Solution of dwell time; At the same time, in order to eliminate the high-frequency shape errors caused by discontinuities at the edges of the face shapes, the original shapes need to be extended to achieve smooth connections. The two-dimensional Gercherg bandwidth-limited continuation algorithm can achieve this requirement. The simulation results show that the root mean square value (rms) and peak-valley value (pv) converge from the initial 0.2534λ, 1.494λ (λ=632.8nm) to 0.0158λ and 0.393λ, which proves the effectiveness of the algorithm. Compared with the Lucy-Richardson algorithm, other traditional solving methods have simpler calculation process, higher calculation efficiency, and higher convergence rate.

In a multi-robot bonnet polishing system, the mobile space between robots overlaps with each other, so collision detection is the premise of the safe and stable operation of the system. The sphere and capsule bounding boxes are used to simplify the model of the multi-robot bonnet polishing system, and the collision detection problem is transformed into the judgment of intersection among bounding boxes in the simplified model. The intersection of bounding boxes is preliminarily judged by the second projection method. The bounding box is projected into line segments. It avoids a lot of multiplication and square operation. If the projection line segments are not overlapped, the bounding box will not intersect. If the projection line segments are overlapped, the problem is transformed into the shortest distance solution from point to point, point to line and line to line. Using space geometry method to calculate the shortest distance between point and line segment. Using the method of transforming reference coordinate system to calculate the shortest distance between two line segment. Through the analysis of simulation software, compared with other algorithms, the average time consumed of the algorithm is reduced by 100%, and the detection efficiency is significantly improved. The algorithm can be better applied to multi-robot bonnet polishing system.

Aiming at the problems of low measurement efficiency and large measurement error when manually measuring the width of the welding seam using the welding seam ruler, a method for measuring the width of the weld seam based on machine vision was proposed in this paper. Firstly, the hardware of the measuring device was designed. The hardware included a measurement platform, an image acquisition and control module, a computer. One motor guide, one stepper motor, an industrial camera and a lighting source were installed on the measurement platform. Secondly, based on Matlab + OpenCV, the measurement software was developed. The software included five functions: controlling the stepper motor and the lighting source, receiving weld seam images, preprocessing the images, segmenting images, correcting images and calculating the width of the weld seam. The image segmentation was implemented by GrabCut algorithm, which could extract the weld area very well. The calculation of the weld width was based on the imaging size and resolution of the industrial camera and the pixels positions on the upper and lower edges of the weld area. Finally, a measurement experiment was carried out on the width of the weld. According to the measurement results, the measurement accuracy of the width of the welding seam reached to 0.1 mm and the measurement speed reached to 30.7 mm / s. The results showed that measuring the width of the welding seam based on machine vision could replace manual measurement and be applied to industrial automation.

With the development of microscopic camera, focusing technology, which is an indispensable component of microscopy camera, constantly develops in the field of automation and high precision. The auto focusing microscopy camera which extremely meets the needs of this period appears at the same time. The climbing searching method is one of the most widely used fast search algorithms on microscopy camera. But the method has its shortcomings. It is weak in anti-noise capability and it can’t correctly identify the search direction in the area far from the focus. It will cause the camera fail to focus accurately and quickly. This paper proposes an implementation method of an auto focusing microscopic camera based on the UVC protocol, which can effectively solve the shortcomings of the climbing searching method and achieve fast , accurate focusing. At the same time, based on the UVC protocol, the microscopy camera outputs and is controlled through the USB3.0 interface, which improves the convenience of use.

Nowadays, microscope cameras that use single operating system are popular. However, both general operating system and real-time operating system have their limits, leading to the conflict of the need of quick start and good scalability. This paper proposed a quick-start HDMI microscope camera with Linux-Huawei LiteOS dual operating system architecture based on the HiSilicon Hi3559V200 platform. It solved the contradiction between the need of quick startup and good function scalability. The Linux system has good peripheral compatibility and good function expandability. Huawei LiteOS, as a real-time operating system, has the characteristics of fast startup, small size, good real-time performance, and good stability. With the dual operating system architecture, this camera can make full use of the advantages of both operating system.

In this paper, a new type of wheel polishing tool is designed. Through the bevel gear structure, only one motor is used to realize the revolution and rotation of the polishing wheel, which makes the structure simple, small inertia, and stable operation. Traditional polishing wheels have a three-layer structure: internal rigid hub, middle flexible rubber, and external polishing pad. It is found through experiments that the hardness of rubber has a greater influence on the tool influence function (TIF). Therefore, by optimizing the hardness of the rubber, we obtained a TIF very close to the Gaussian shape, which is conducive to the rapid convergence of the surface error. Finally, the effects of polishing wheel speed, polishing pressure and polishing time on the TIF, as well as the stability of the TIF, are studied through experiments. Experiments show that: (1) There is no linear relationship between the removal efficiency of the polishing wheel, the polishing wheel speed, and the polishing pressure, but as the parameter increases, the increase in the removal efficiency slows down; (2) There is a good linear relationship between the removal amount of the polishing wheel and time; (3) The TIF is very stable, and the stability of the TIF reaches 98%.

As the caliber of a Spatial Optical Remote Sensor increases constantly, it is an inevitable trend to design a highly lightweight mirror. In the testing process of the mirror surface with a large caliber and higher lightweight level, the supportive distortion caused by gravity is a crucial factor that influences its testing precision. Aiming at this problem, we studied a testing method on the rail surface of the tested mirror that was detached from the gravity field. Deviations of the mirror wave surface were expressed by Zernike polynomial functions, so that wave surface data from different angles could be calculated by superposition. The optical axis vertical approach is adopted to test the wavefront of the aspherical mirror. By rotating the measured mirror, the surface shape data in different directions is tested. Through superposition calculation of the Zernike coefficients, the cumulative error of the test optical path is eliminated. In the same approach, the wavefront data of the surface of the reflecting mirror after rotating 180 degrees is measured . By using the finite element analysis, it is known that the deformation directions of the reflecting mirror in the two states are opposite caused by gravity during the test. And the orbital surface deformation data of the mirror can be obtained by calculation.

With the development of industrial production, machine vision is playing a more and more important role in measurements and judgments. For the machine vision system, double-telecentric optical system can be used for visual inspection and measurement with good imaging effect and imaging accuracy. This paper mainly introduces a low telecentricity and low-distortion double-telecentric optical system. The designed system consists of only 5 lenses, which will reduce production costs. The object field of view is 50mm, the working wavelength is visible light, the total length of the system is 274mm, the working distance is 110mm, the maximum distortion is less than 0.025%, the object side telecentricity is better than 2.6×10^-6 milliradians, and the image side telecentricity is better than 7.6×10^-4 milliradians. The MTF is greater than 0.3 at the Nyquist frequency 91 lp/mm for the full field of view. The MTF curve of the optical system is close to the diffraction limit, which indicates the optical system has good imaging quality in space. The optimizing process and tolerance analysis of the optical system are showed in this paper. The results indicate that the double-telecentric optical system can be used in the production and inspection of parts in the industry.

Sub-aperture stitching interferometry can be used for measurement of wavefront of large aperture optical system. A variety of sub-aperture stitching algorithms have been studied to reconstruct the sub-aperture data to obtain full aperture wavefront. The simultaneous fitting method plays an important role among those stitching algorithms which uses a series of global polynomials to accomplish the fitting of the test wavefronts, however, it can only be applied in the case of there have no overlap between each sub-apertures. Therefore, a modified simultaneous fitting method is proposed and is applied to measure the wavefront of large aperture optical system. The proposed algorithm is applicable whether there exists overlap between each sub-aperture or not. The numerical simulation is carried out to evaluate the accuracy of the algorithm. Further, a practical stitching experiment that test an optical system with a diameter of 850mm was implemented to demonstrate the modified algorithm.

This article has designed a wide-angle digital micro-projection lens suitable for a 0.55″ DMD chip with an aspect ratio of 1:2 using ZEMAX optical software. The structure of the lens consists of 3 aspherical lenses. It adopts "negativepositive-positive" type reversed telephoto structure, and the lens material is optical plastic PMMA. It can well solve the problems of the off-axis aberration correction and image surface illumination uniformity for wide-angle lens. It has the characteristics of simple structure, small size, easy processing, low cost and large rear working distance. The effective focal length of the lens is 11.163mm, the relative aperture is 1/1.8, the full field of view is 64°, the maximum aperture is less than 32mm, and the total optical length is controlled at 103.6mm. For car lighting, the lens has good imaging quality. At a resolution of 16.5lp/mm, the modulation transfer function (MTF) value of all fields of view is greater than 0.45. The lens is imported into the professional car light distribution software LucidShape to simulate, using a million rays to traces, the result of light distribution meets the current only ADB light distribution regulations, and can achieve various pattern projections.

When the camera is actually used, it is necessary to provide the user with a picture preview function on the HDMI interface, that is, to browse multiple pictures on one interface. Based on the JPEG format specification and Exif specification, combined with multi-thread decoding display technology, this paper proposes a new quick preview scheme for multiple pictures. Even if you switch and preview multiple ultra-high-definition pictures by this shceme, the refresh display speed is very fast, and it is easy to maintain later and has good stability.

A flat-top and low-crosstalk 4-channel wavelength-division multiplexer based on LN thin film is designed. By utilizing narrow straight directional couplers, the crosstalk is <-10 dB and -3 dB bandwidths are ~20 nm for all channels

A computer-generated hologram(CGH) was designed and produced for precisely testing the off-axis aspheric mirror with departure of 1200um in a three mirror astigmatism optical system．To solve the problem of selection of incident light position in CGH design Depended on engineering experience was likely to increase spatial frequency of CGH which reduced testing accuracy of aspheric mirror. A CGH design method was proposed based on quantitative calculation of incident light position which reduced the reliance on experience. The testing result by CGH was compared with that of non-contact profile testing method when the off-axis aspheric mirror surface was polished to 0.05λ（RMS）.Two testing results show a good agreement. By CGH testing method，the surface error is 0.016λ RMS now．

The defects on the complex texture surfaces can be detected with the traditional machine vision detection technology， which is mainly based on the characteristic differences in the gray scale between the surface intrinsic texture and the defect texture. And also, the height feature can be used in the detection with a 3D sensor. However, the problems can be encountered with these methods, such as the low detection efficiency, high misjudgment ratio, or high cost. To solve these problems, in consideration of the practical application, the defect detection method of the complex texture surfaces based on the multi-segment computational imaging technique (MSCIT) is presented in this paper. On the one hand, the multi-angle images of the surface can be obtained, through the time-sharing trigger of a multi-segment combination of light sources and monocular camera. On the other hand, the gradient information of the surface is restored, according to the different shadow images generated by multiple incident lights and the direction vectors of lights. Then, based on the surface gradient distribution and the image preprocessing technology, the defect information can be enhanced and the intrinsic texture properties of the surface can be weakened. The experiments, carried out on complex texture surfaces with different properties, show that the MSCIT can prevent the useful detected information from being disturbed by the complicated background. The MSCIT proposed in this paper can form a general technology of defect detection of the complex texture surface, and the engineering applications can be achieved.

In the design of industrial camera systems, it requires high video image quality, fast frame rate and real-time video image processing. The FPGA has the advantages of parallel processing, abundant resources and field programmable, it provides a hardware implementation platform for real-time industrial camera system design. This paper uses FPGA, CMOS image sensor, DDR3 SDRAM memory and USB3.0 chip to realize system function design of video acquisition, image preprocessing, image cache and image transmission. Video acquisition uses Sony IMX455 image sensor to acquire video images. Image preprocessing uses Microsemi FPGA to realize data deserialization and hardware ISP functions. Image cache uses DDR3 SDRAM memory to achieve multi-frame image cache. Image transmission uses USB3.0 chip to transmit image data to the host computer. The experimental results show that the industrial camera system only uses a single FPGA to complete image sensor control, high-quality image preprocessing and real-time image cache, which can stably obtain 9568*6380@6.4fps video images.

The R₂O-SiO₂-B₂O₃ glass has emerged as an important material due to its high performance. During the process of glass melting, copious amounts of bubbles can be produced. The bubbles are considered as serious defects of the R₂O-SiO₂-B₂O₃ glass and can induce negative effects on properties of glass, such as optical uniformity, mechanical property, etc. The influence of the fining agents on the properties of R₂O-SiO₂-B₂O₃ glass such as density, refractive index, and transmissivity were systematically studied. The results indicate that fining agents had influence on the density of the R₂O-SiO₂-B₂O₃ glass, fining agents do not have obvious impact on the refractive index and transmissivity of R₂O-SiO₂-B₂O₃ glass.

To investigate the distribution characteristics of subsurface damage in fused silica, three different machining methods - cutting, grinding and lapping were adopted. The method of combination of step-by-step polishing and wet etching were applied to expose the subsurface damage and their distribution characteristics in horizontal and vertical directions were analyzed and compared. Experiment results showed that the numbers of subsurface cracks induced by different processes have similar exponential distribution in depth, although their maximum depths were varied with machining methods. Most of the cracks, more than 90%, distribute within half of the maximum crack depth, while only a few cracks extend deeper and contribute the maximum SSD depth. The ratio of SSD depth to Rz for lapping, slicing and grinding based on our work are about 1.4, 1.8 and 2.8, respectively. The present results indicate a nonlinear correlation between SSD depth and Rz.

In this paper, by constructing a 3-DOF (Degrees of freedom) laser interferometer on each displacement axis of motion, the main errors during the coordinate measuring machines (CMM) motion are dynamically monitored. The 3-DOF laser interferometer is composed of three-beam dual-frequency laser interferometers, and each dual-frequency laser interferometer obtains the reflection signal through a corner cube reflector. By determining the position parameters of the three corner cube reflectors and three sets of feedback signals, the 3-DOF laser interferometer can calculate the three parameters, i.e., the axial displacement and the lateral pitch and yaw angles. The device is installed on each motion axis of the CMM to monitor 9 major errors during the whole motion system. Laser signals are used to track position information by establishing the rigid body transformation relationship. Therefore, the 9 errors can be updated in real time through the monitoring system to replace the calibration results to calculate the probe position. The position error of the CMM probe caused by the dynamic error is simulated. Monte Carlo method is employed to obtain the error situation and monitor the residual error distribution throughout the measurement movement process. The errors can be corrected immediately without recalibrating the CMM error parameters especially when the dynamic error changes significantly. In addition, environmental errors are also introduced in the model to analyze the impact on the accuracy of position monitoring. The method proposed can reduce the position monitoring error within 0.1 μm. Using this method, the error source of a dynamic error monitoring system can be designed in a simulated environment, which can be used as the basis for the design of the dynamic error monitoring system.

From precision machining to green manufacturing, the search for an economical and effective green manufacturing chain system has gradually become the focus of the metal processing industry in order to ensure the quality of workshop manufacturing, increase the production capacity per unit of energy consumption, and reduce processing consumables. The existing research The focus is more on the establishment of the objective function model, the optimization method used and the targeted optimization direction are relatively single, and a more complete manufacturing system has not been established. There are three main optimization goals for processing process parameters in this subject: starting from the direction of processing quality, reducing the surface roughness of the workpiece as the optimization goal, establishing a cutting surface integrity (Ra) function; starting from the direction of enterprise manufacturing, to improve milling efficiency Optimize the objective and establish the cutting efficiency (SEC) function; starting from the processing cost, to reduce the amount of tool wear as the optimization objective, build a machine tool tool wear visual inspection mechanism to assist in the establishment of the tool wear (VB) function, and introduce a non-dominant sorting genetic algorithm to obtain Pareto After the frontier solution, different optimization suggestions are proposed for the refinement of rough/finish processing and general processing. The results show that the NSGA-Ⅱ model has a stronger search ability than the GA model when faced with multiple quasi-measurement decision problems. The processing efficiency can be increased by 42.7%, the tool cost can be saved by 25%, and the workpiece quality can be increased by 21.8%.

For the existing ultraprecision fly-cutting machine tools, the cutting depth needs to be adjusted by the engineer manually, the cutting efficiency of Potassium Dihydrogen Phosphate (KDP) crystal is low and the error is large. In order to solve the problems of the existing ultraprecision fly-cutting machine tools, such as the need for engineers to manually adjust the cutting depth, low cutting efficiency and large error of KDP crystal. In this paper, a parallel high bandwidth nanometer feeding mechanism driven by piezoelectric ceramics with high resonance frequency and compact structure is designed for ultraprecision fly-cutting machine tools. The designed three-degree-of-freedom nanometer feeding platform can achieve precise deflection in θx and θy directions, and precise vertical movement in z-axis direction which can be used for micro-feeding and fine-tuning of KDP crystal. The static analysis and modal identification of the micro-feed platform are carried out to verify the static and dynamic characteristics of the designed device. In order to further verify the correctness of the finite element simulation, the experimental modal analysis of the micro-feed platform is carried out. The correctness of the finite element model is verified, and the natural frequency is high, which enables the micro-feed platform to obtain better dynamic response performance.

The ultrasonic vibration cutting (UVC) method is an efficient cutting technique for the hard and brittle materials. The influence of ultrasonic vibration parameters on the critical cutting thickness (CCT) of single crystal silicon was investigated by spirally grooving experiment, and a series of experimental trials were carried out by using different cutting duty ratios (CDR). The results show that: the ultrasonic vibration efficiency is closely related to CDR, and increases with the decrease of CDR; when the ultrasonic vibration frequency and velocity were fixed, the CCT decreases as the vibration amplitude increases; the smaller the CDR is, the higher the surface finish of single crystal silicon machined by UVC will achieve. In the cutting tests, the experiment in which the value of CDR is 0.13, realized the ductile mode cutting for the Φ100mm specimen in the whole area.

Aiming at the shortcomings of the existing photoelectric pulse wave acquisition and analysis chip with large volume or no data processing and analysis function in the prior art, this paper proposes a small and highly integrated heart rate blood oxygen monitoring system solution with a built-in pulse wave algorithm. Its internal data acquisition and analysis module is as small as 3 × 3mm² . The position of each module on the PCB is reasonably distributed, and the overall structure of the heart rate and blood oxygen monitoring system is miniaturized. The integrated monitoring system can be as small as 7 × 15mm² , which makes the heart rate oximetry system can be embedded in more portable products. The software algorithm first performs an average filtering process on the original signal. Then, the differential threshold method is used to extract the characteristic points of the pulse wave signal, that is, the maximum value and the minimum value, so as to obtain the positions of the peaks and troughs. The heart rate value is calculated based on the time difference t between two adjacent peaks of the light signal reflected by the red light source during the period. The experimental results show that the heart rate error of the integrated system can reach ±2% + 1 times / minute, and the blood oxygen error can reach ±2% within the range of 70-100.

Temporal phase-shifting interferometry technique (TPSI) has high accuracy in surface topography metrology and has been designing to diagnose the surface variation of plasma-facing materials (PFMs) in Tokamak. But the mechanical vibration of the Tokamak device will lead to the decrease of the measurement accuracy or even incorrect result. In order to solve the problem more, it is much desired to study the influence of the vibration on the topographic measurement in the broad parameter scope. Series experiments in the different vibration frequencies, amplitudes, modes and different deformation amounts and detection wavelengths were carried out in this work.

Meter-level aspheric mirrors are the core optical products in space optical remote sensors. With the development of space optical remote sensing technology, the mirror manufacturing quality have gradually evolved from focusing on some key parameters in the past to global control of full index parameters. This is undoubtedly bringing great challenges for optical fabrication and testing. Taking a typical meter-level aspheric mirror as an example, the article introduces a full-parameter process control method for aspheric mirrors for space applications. First of all, in the aspheric surface shape milling and grinding stage, the contour measurement method is used to initially control the radius of curvature of the mirror surface, the aspherical surface coefficient, the effective aperture and the deviation of the optical axis; secondly, after entering the rough polishing stage, the mirror surface is quickly improved at the same time as the roughness index of the mirror, it improves the accuracy of the mirror surface shape and controls the mid-to-high frequency error. Finally, in the fine polishing stage, the method of gravity unloading is used to acquire the zero-gravity surface shape of the space mirror. The geometric and optical parameters of the mirror converge to the expected value, of which the error of the vertex curvature radius is better than 0.5mm; the error of the aspherical coefficient is better than 0.01%; the deviation of the optical axis is better than 1′/ 1mm, and the rms of the surface shape accuracy in the whole frequency band is better than 10nm, the low-band error is better than 8nm, and the mid-band error is better than 3nm; the surface roughness rms is better than 1nm, and the remaining parameters meet the needs of camera on-track applications. The proposed process control method has been expanded and can also be applied to high-precision manufacturing of aspheric mirrors in the range of 1-4m.

A new phenomenon of random variation effect on the fiber height in optical fiber connectors is researched. The mechanism of this effect is proposed and analyzed. Based on the theory, this effect is caused by epoxy adhesive that used in fiber connectors under extreme temperature. It is deduced that glass-transition temperature of epoxy adhesive contributes a critical role in this effect. And further investigation is applied to verify this theory. The result demonstrates that the fiber height in optical fiber connector’s contact will be significantly affected if working above the glass-transition temperature of used epoxy adhesive.

The fully continuous spiral phase plate (SPP) has been used more and more widely in high-power laser and other fields. Its unique jump cross section structure with a width of only a few millimeters puts forward extremely high requirements for wavefront measurement. In this paper, a defocus multi-intensity phase retrieval algorithm based on weighted GS for wavefront measurement of SPP is proposed, and the influence of phase retrieval test error on measurement accuracy is analyzed. Finally, a phase retrieval test platform is established, and the high-precision phase retrieval measurement of the SPP wavefront is realized.

Generally, the surface vibration velocity amplitude of a conventional rectangular acoustic probe is the same. Because of strong interference, the radiated sound field in the near-field is extremely uneven, and radiation side lobes appears in the far field, which are not conducive to its application in ultrasonic technology. A rectangular acoustic transducer with Gaussian vibration velocity distribution on the acoustic radiation surface can reduce or avoid the near field of extreme inhomogeneity and far-field side-lobe. So it can be used in medical ultrasound diagnosis and industrial nondestructive testing and can obtain better effect. In this paper, the radiated sound field of a rectangular transducer with Gaussian distribution of surface vibration velocity is calculated, theoretically. The medium is isotropic without attenuation. The center of the rectangular transducer is assigned as the origin of coordinates. And the plane of the surface is as XOY surface. Then the coordinate system is established. Using Rayleigh integral method, the calculation of the radiation sound field is carried out. Discussion of the acoustic field distribution including on the beam axis and the far field is carried out. It is found that the sound field distribution on the beam axis is closely related to the parameters of the transducer surface. The oscillation of the sound pressure on the beam axis can be avoided by adjusting the parameters. There is no side lobe in the far field. The study of this paper can provide a theoretical suggestion for the application of Gaussian rectangular transducer.

Additive Manufacturing (AM) technology is considered as one of the most promising manufacturing technologies in the areas of aerospace and defense industries. However, the AM parts are known to have relatively high residual stresses and a variety of defects, such as porosity, balling, cracking, etc. Therefore, it is critically important to monitor the quality of products during the AM manufacturing process. In this paper, we proposed a novel enhanced fusion algorithm based on Finite Discrete Shearlet Transform (FDST) and multi-scale sequential toggle operator (MSSTO) for visible and infrared images fusion in the AM systems. The original images can be decomposed into low-frequency and high-frequency subband images by FDST. Then, the effective bright and dark image informations are extracted from the low frequency coefficients of source images by MSSTO transform, which are injected into the fusing low frequency coefficient to obtain the final low frequency synthetic coefficient. The high frequency sub-band coefficients are fused by using the local spatial frequency weighting and region energy. The fused image can be obtained by the FDST inverse transformation of the high and low fused coefficient. Experiments show that the proposed algorithm can get more texture information while retaining the significant features of the images, acheiving good detection and indetification results of the defects properties.

This paper proposes an interferometry method based on a fixed interferometer structure and locally compensated stitching. The subaperture measurement is completed by applying a double-optical-wedge compensator in the "rugged" area of the surface that cannot be measured. The data of the measured area is stitched to obtain the local surface shape. The calibration of the double-optical-wedge compensator is performed by using a standard mirror. Surface figure error (SFE) of the standard mirror is measured by an interferometer beforehand. Compared with the SFE measured after adding the compensator in the optical path, the phase and aberration of the double-optical-wedge can be obtained. Measured data is processed by the subaperture stitching algorithm. Through the weighted fusion algorithm, the corresponding data values on the overlapping areas are weighted, and different weights are assigned to different areas to make the stitching transition smooth. Based on the principle of interferometry, a double-optical-wedge compensation measurement system is designed and implemented. A simulation model of the measurement experiment is presented, and the validity of the method is verified by simulation.

In aerospace, petroleum, special equipment and electric power industries, ultrasonic non-destructive testing technology is widely used. A large number of rectangular ultrasonic transducers are adopted, including the one dimensional linear phased array ultrasonic testing which is widely used, recently. So the sound field characteristics of the rectangular transducer is critical for these applications. Because of the small attenuation in the medium, we ignore the attenuation in the material. In this paper, the acoustic field characteristics of the rectangular transducer are discussed. Firstly, the coordinate system is established and the analytical solution of the acoustic field distribution of the rectangular transducer is derived in detail by using Rayleigh integral method with Fresnel approximation. Secondly, the distribution characteristics of sound pressure on the beam axis are discussed, and the length of the near field is calculated. Finally, the calculation of far-field sound pressure with the Fraunhofer approximation is carried out. And the relationship between directivity and probe parameters is discussed. The study of this paper provides important suggestions for the process design of ultrasonic inspection by using rectangular transducers.

Based on Hertzian theory and a theoretical model considering the flexibility of the carriage, this article established a model to describe how the vertical stiffness of preloaded linear rolling guides with cylinders changes.A method of iterative calculation is adopted to solve the problem.According to the results of finite element analysis, the deformation range of a double guide platform is predicted.

Subsurface damage (SSD) of fused silica elements formed by grinding and polishing will produce high-energy laser modulation and absorption effects. Further induced macro damage will seriously decrease the precision of the optical system and shorten the service life of the optical element. Because of the limit of the optical manufacturing technology, cost, and other reasons, it is hard to grinding and polishing without generating SSD. Thus, efficiently suppress the depth of SSD becomes an important research direction to further enhance the accuracy of the optical system. We use the equations for median and lateral cracks depths to predict the depth of SSD and surface roughness (P-V value). The equations are derived by Lambropoulos from micro indentation mechanics and hill model for indentation of a sharp indenter. The lateral cracks theory and the measurement data on the high-precision roughness measuring instrument are used to solving and verify the grinding empirical formula. This can effectively solve the problems of detecting indentation normal load during process. The empirical formula is then combined with the equations for median and lateral cracks depths to establish an optimization model. With this model, we design an optimization algorithm to optimize the parameters of process to suppress the depth of SSD. Gradient algorithm is used to optimize the parameters of the whole process, and design a high efficiency fused silica process solution to obtain a minimal depth of SSD and high-precision surface. The above algorithm has certain universality for different processing machines, materials, and processing conditions. Change the material parameters and constraints can quickly obtain the corresponding processing parameters.

The influence of mid-spatial frequency surface error on illumination pupil in the lithography illumination system is analyzed. The far-field distribution of the pupil under the influence of the mid-spatial frequency surface error is derived. Using the actual manufactured surface error combined with commercial optical design software to simulate the relay lens group in the photolithography illumination, analyze the influence of the mid-spatial frequency surface error in different fields of view on the pupil ellipticity, X-direction pupil balance and Y-direction pupil balance. This simulation method can be used at the design stage by using the actual manufactured profile, which provides a reference for optical design.

Spectral confocal displacement sensor is a kind of non-contact displacement sensor based on wavelength shift modulation. The principle of spectral confocal measurement transforms the displacement information into the wavelength information, and obtains the measured displacement through the spectrum measurement. Large aperture aspheric surface is the core component of optical system, and its measurement accuracy is directly related to the imaging accuracy of optical camera. The non-contact differential confocal method has the characteristics of non-contact and highprecision. Through the integration of dual frequency interferometer to accurately measure the distance and real-time compensate the measurement distance, the nano level high-precision surface measurement results are obtained, and the measurement accuracy of optical components is improved. In this paper, the non-contact differential confocal method is used to detect the concave aspheric surface with a diameter of 300 mm. Through error file compensation, the surface shape detection accuracy is improved to 12 nm rms, and the scanning detection accuracy is greatly improved to the interference detection accuracy, which meets the imaging requirements of optical system.

Panoramic photography is now more and more used, it can become an important part of VR technology, 360° imaging and fish-eye wide angle photography. But in the studio or indoor environment, how to give panoramic photography lighting is a difficult thing, so we need a small, can spread the light source very well. This paper designs a light distribution method based on aspheric lens for photography light source, which can spread the LED light source in a compact space. Because the size of the lamp is very small, it can be hidden in the scene of panoramic photography. In the process of photography and imaging, it does not enter the image picture or produce noise light. This light setup can diffuse rays very wide angle, which can be used in panoramic image or ordinary indoor photography.

In this article, we propose a 3D shape measurement technique based on a novel structured light encoding and decoding scheme . In this technique, as few as three images can be used to obtain the absolute 3D shape of the measured object. By adding perturbations to the Hamiltonian coding patterns, new coding patterns which have higher performance can be obtained. These patterns are projected onto the measured object, then normalized cross-correlation (ZNCC) decoding is performed using the obtained image sequence. The experimental results verified that our method is feasible.

In order to measure the aspherical transmission wavefront of large aperture optics with wedged angle, three compensators were fabricated based on theories of geometrical and diffraction optics, a single null lens and two computer-generated-holograms (CGH) by different frequecy carrier. The results show that both refraction null compensator and diffraction plate can achieve high-precision wavefront measurement of large aperture aspherical optics, the difference of wavefront measured by refraction and diffraction methods is better than 0.01λ(RMS) in the effective aperture area. Because of the measure beam deviation caused by the optic wedge, the results is very sensitive to parts position and gesture. Due to a smaller divergence angle and extra alignment/fiducial area for precision adjustment, the primary aberrations of tilted CGH measurment can get a better control than that of null compensator. Precise control or adjustment of compensator is critical for aspherical wavefront measurement. Null compensator lens can easily induce regulation error while CGH method could cause mid-frequency disturbance.

To meet the fast and high precision manufacturing requirements of space optical system, experimental research on rapid processing and testing of a 316mm aperture free-form optical mirror was carried out and current fabricating technologies were optimized. In terms of rapid fabrication, process parameters of ultrasonic vibration-assisted grinding were improved firstly, and the method of expending and removing of the optical surface edge based on robot polishing is adopted. In terms of testing, applying scanning white light interferometry (SWLI) technology based on CMM machine to test the surface figure can improve the detection efficiency by more than 10 times when the density of the test point is 100 times higher than point contact CMM testing mode. Finally, the result shows that The accuracy of full-aperture inner surface of free-form surface is better than that of λ/55 RMS. The total time of effective machining and testing of free-form surface is less than 360hrs. The results show that the Optimized process has the advantages of efficiency compared with traditional process and can also achieve high precision at the same time.

Rectangular transducer is widely used in industrial non-destructive testing. Current studies generally assume that there is no attenuation in the medium. In this paper, the distribution characteristics of the radiated sound field in attenuation media of a rectangular transducer are theoretically calculated. Firstly, considering the attenuation of the medium, the analytical expression of sound field distribution in The Fresnel region is derived under the condition of Fresnel approximation. Secondly, the distribution characteristics of sound pressure on the beam axis are discussed. Finally, the sound pressure distribution in the far field is calculated using the Fraunhofer approximation and compared with the case without attenuation. This study provides an important reference for the method and process design of using rectangular transducer to detect attenuation materials.

Microlens array is a fundamental optical components that are widely used in the various applications including 3D display, light homogenization and 3D imaging. Lots of advanced fabrication techniques have been demonstrated for producing microlens arrays with different geometries, profile and optical properties. However, microlens arrays with high filling factor whose microlenses are closely packed are hard to realize due to the difficulty in 3D micromanufacturing techniques. In this research, a novel rapid and low-cost microfluidic-manipulation based technique is proposed for fabricating high-filling-factor microlens array. An array of micro-holes are firstly prepared as mold on a silicon wafer by lithography technique. Then, polydimethylsiloxane (PDMS) is used to replicate the micro-hole array to form the micro-post array. After that, liquid-state PDMS is spun over the micro-post array and solidified. Due to the existence of the micro-posts, PDMS presents wavy fashion. The PDMS right on the top of the micro-posts becomes spherical cap while those in between the micro-posts becomes valley due to the capillary effect. The microlenses are closely attached to each other and the entire mircrolens array is highly packed. In this paper, we present a preliminary demonstration about the fabrication. A microlens array is formed on a 500 μm in diameter micro-post array. The closely packed microlens array patterned in square style achieves the filling factor above 78.54%. The geometry and profiles of the microlenses could be designed and controlled. The easy-to-operate fabrication technique is suitable for mass production of microlens arrays.

The research object of surface defects in optical glass processing is mainly focused on the surface of homogeneous monomers, but there are few reports on the surface polishing defects of composite materials with a variety of monomers with different physical and chemical properties. In this paper, the defect samples with different characteristics are obtained by changing the types of optical fiber image transmission elements, adjusting different polishing processes and parameters. The structure and morphology of the defects on the surface of optical fiber image transmission components are observed by white light interferometer and atomic force microscope. The composition at different positions and the combination of chemical elements are determined by Energy Dispersive Spectrometer (EDS). The specific reasons for the defects are analyzed, the optimal polishing process and corresponding parameters are obtained, and the mechanism of the formation of defects on the polished surface of optical fiber image transmission elements is clarified. The results of the study have a certain guiding significance for the control of polishing defects on the surface of composite materials composed of various monomers, and provide data and theoretical support for improving the polishing quality and efficiency of optical fiber image transmission components.