This PDF file contains the front matter associated with SPIE Proceedings Volume 9684, including the Title Page, Copyright information, Table of Contents, Introduction (if any), and Conference Committee listing.

We present a transmitted wavefront measuring system of large optic modules based on Shack Hartmann wavefront sensor, aiming to perform optical metrology for rectangular laser slabs arranged in a 4-high by 1-wide matrix. This system is developed to perform high-accuracy measurement for extremely high quality optical components needed for inertial confinement fusion (ICF) facility with wavefront accuracy better than 0.4λ (peak to valley, λ=632.8nm). Sensitivity analysis is put forward to specified tolerances of components to ensure the built system will perform as desired. Experiments results showed that added wavefront of each slab of 32 matrix modules is controlled under 1λ successfully.

The velocity of warhead fragment is the key criteria to determine its mutilation efficiency. But owing to the small size, larger quantity, irregular shape, high speed, arbitrary direction, large dispersion of warhead fragment and adverse environment, the test of fragment velocity parameter is very difficult. The paper designed an optoelectronic system to measure the average velocity of warhead fragments accurately. The apparatus included two parallel laser screens spaced apart at a known fixed distance for providing time measurement between start and stop signals. The large effective screen area was composed of laser source, retro-reflector and large area photo-diode. Whenever a moving fragment interrupted two optical screens, the system would generate a target signal. Due to partial obscuration of the incident energy and the poor test condition of the explosion, fragment target signal is easily disturbed. Therefore, fragments signal processing technology has become a key technology of the system. The noise of signal was reduced by employing wavelet decomposition and reconstruction. The time of fragment passing though the target was obtained by adopting peak detection algorithm. Based on the method of search peak in different width scale and waveform trend by using optima wavelet, the problem of rolling waveform was solved. Lots of fragments experiments of the different types of the warheads were conducted. Experimental results show that: warhead fragments capture rate of system is better than 98%, which can give velocity of each fragment in the density of less than 20 pieces per m².

Physical properties, such as density, refractive index and morphology of the aerosol particles will be changed when the relative humidity of the environment is relatively high, which leads to a significant variation of the scattered light signal collected by the single particle light scattering measurement system. If the calibration parameters in the condition of low humidity are applied to inverse aerosol mass concentration, the measurement accuracy will certainly be degraded. Therefore, the calibration parameters of the system must be corrected. In this case, the monotonic relationship between the particle size and the scattered light signal collected by the system should be considered carefully. Combining the Mie scattering theory with the humidity growth model of the particle size and the refractive index, the influence of relative humidity on the scattered light signals of spherical particles has been investigated in this paper. The results indicate that the diameters of spherical particles grow exponentially and the refractive index decreases linearly when the relative humidity is increased between 60% and 95%. Consequently, a significant change of the angular distribution of the scattering intensity occurs. The forward-scattered light is getting stronger, while the back-scattered light becomes weaker. Meanwhile, the scattered light flux of the particle within a solid angle displays exponential growth with increasing the relative humidity. Thus, the monotonous relationship between the particle size and the scattered light flux has changed significantly in the case of the high humidity, and their quadratic coefficient decreases clearly assuming the particle density invariant, which causes an obvious increase of the calibrated proportional coefficient. The results of this work provide an important theoretical guidance for the humidity correction of calibration parameters for the inversion of aerosol mass concentration by the single particle light scattering method.

A near infrared reflective shearing point diffraction interferometer (NIRSPDI) is designed for large-aperture dynamic wave-front measurement. The PDI is integrated on the small substrate with properly designed thin film. The wave-front under test is reflected by the front and rear surfaces of the substrate respectively to generate an interferogram with high linear-carrier frequency, which is used to reconstruct the wave-front by means of the Fourier transform algorithm. In this article, the system error and the major parameters of NIRSPDI are discussed. In addition, we give an effective method to adjust NIRSPDI for fast measurement. Experimentally NIRSPDI was calibrated by a standard spherical surface and then it was applied to the dynamic wave-front with a diameter of 400mm. The measured results show the error of whole system which verifies that the proposed NIRSPDI is a powerful tool for large-aperture dynamic wave-front measurement.

Off-axis paraboloid (OAP) is widely used in optical system of large diameter, such as astronomical instruments, space optics and so on, for it produce no aberration at geometric focus. It simplifies the structure of optical system, improves imaging quality, reduces the size and weight, also cost of the system. The software Zemax was used to simulate the adjustment errors including high-low and pitch, tilt and off-axis distance, and the rotation around the secondary optical axis, by taking an off-axis paraboloid mirror with the diameter of 400mm, focal length of 4000mm, and the off-axis distance of 350mm for an example. Then the corresponding experiments were performed to verify the simulation results using PhaseCam6000 interferometer of 4D technology. It proves the simulation model in correct, will play an important role in adjusting an off-axis paraboloid mirror.

With the advantages of easy data processing and fast measuring speed, line structured light sensors (LSLSs) have gained more and more applications. CCD camera is a core component of the sensor. The distortion of its lens will severely degrades the measuring accuracy. To enhance the measuring quality, a numerical calibration method is brought out that is based on linear transformation over triangular domain. Based on the pinhole imaging principle, a linear transformation model was established which is easy to compute the profile’s world coordinates according to its pixel coordinates over each triangular domain. The triangle domains are achieved using Delaunary triangulation via the centers of target dots. The triangle number that each center point of the laser stripe locates is determined by T-search method. A linear approximation error model to the lens distortion is also established and the approximation errors are getting larger when the interval spacing of the calibration dots increases. Measuring results show that the relative error of this proposed method in horizontal and vertical direction can reach 0.0630% and 0.0802%, respectively. The calibration error grows with the increasing of the target’s dot interval that corresponds with the trends of the linear approximation error. This further validates the proposed calibration method.

An annular sub-aperture stitching interferometry testing is proposed for large-caliber aspheric lens testing, expanding the dynamic range of the interferometer, broadening the scope of the measurement, and reducing the cost of the measurement to a large extent without the use of compensating elements. The large-caliber aspheric is divided into several annular sub-apertures, and there are some overlapping areas between each two adjacent sub-apertures. When testing, the test aspheric is moved along the optical axis according to path planning so that the reference spherical shape and the test aspheric interest at points of common tangency to reduce the fringe density of the sub-aperture. However, in the process of moving the test optic, six DOF (degrees of freedom) misalignment errors will occur. According to the rigid body kinematics theory, the misalignment error separation model is established so that the misalignment factors can be calculated by the information of each overlapping regions. Then all sub-apertures are unified to the same reference with proper algorithm, and subsequently, misalignment error of the reference is removed by Zernike polynomial fitting, and the whole surface error is recovered. Simulation results are shown to demonstrate the feasibility of the method we developed. By analyzing the influence of the six DOF on the stitching result, the most important factor is obtained, and some measures are taken, that is, a measurement system combining two interferometers is designed, one of which is to measure the departures between the reference and the aspheric, and another to test the piston errors to be transmitted to the control system to improve the accuracy.

Interferometry is an optical measuring method with the character of non-destructive, high sensitivity and high accuracy. However, its measurement range is limited by the phase ambiguity. Hence the method with two separate different wavelengths light source is introduced to enlarge the measurement range.

As for the two-wavelength interferometry case, phase shifting is the traditional way to acquire the phase map, it needs to repeat the measurement twice, which means the measurement cannot be accomplished in real time. Hence to solve the problem, a temporal sequence interferometry has been used. This method can obtain the desired phase information in real time by using the Fourier transform methods of the interferogram recorded in a sequence while the object is being deformed. But, it is difficult to retrieve the phase information directly due to the multi extreme points in one period of the cosine function.

In this paper, an algorithm based on the wavelet ridge analysis is adopted to retrieve the two wavelength phase fluctuation caused by the displacement simultaneously.

The preliminary experiment is conducted and the results are compared with theoretical simulations to validate the proposed approach. The laser emits light with two wavelengths 532 nm and 473 nm, two separated interference patterns in time sequence are detected by the CCD camera in the same time. The overlapped interferograms of two colors are analyzed by this algorithm and the corresponding phase information are obtained. The maximum error value between the simulation and theory is 0.03 um and the relative error is 0.33%.

A conventional VMI (velocity map imaging)-TOF (time-of-flight) spectrometer is modified by adding an extra electrode. By this small modification, the longitudinal focus can be realized for TOF mass resolution while maintaining the lateral focus for optimal VMI energy resolution simultaneously. The mass-resolving power by four-electrode ion optics is greatly enhanced. Our design is especially useful in experiment with a non-focused laser beam.

Reflective triplet (RT) optics is an optical form with decenters and tilts of all the three mirrors. It can be used in spectrometer as collimator and reimager to get fine optical and spectral performances. To alleviate thermal and assembly stress deformation, opto-mechanical integrated design suggests that as with all the machine elements and the mainframe, the mirrors substrates are aluminum. All the mirrors are manufactured by single-point diamond turning technology and measured by interferometer or profilometer. Because of retro-reflection by grating or prism and reimaging away from the object field, solo three mirrors optical path of RT has some aberrations. So its alignment and measurement needs an aberration corrected measuring optical system with auxiliary plane and sphere mirrors and in which the RT optics used in four pass. Manufacture, alignment and measurement for a RT optics used in long wave infrared grating spectrometer is discussed here.

We realized the manufacture, alignment and test for the RT optics of a longwave infrared spectromter by CMM and interferometer. Wavefront error test by interferometer and surface profiles measured by profilometer indicate that performances of the manufactured mirrors exceed the requirements. Interferogram of the assembled RT optics shows that wavefront error rms is less than 0.0493λ@10.6μm vs design result 0.0207λ.

Cylindrical mirrors are key optics of high-end equipment of national defense and scientific research such as high energy laser weapons, synchrotron radiation system, etc. However, its surface error test technology develops slowly. As a result, its optical processing quality can not meet the requirements, and the developing of the associated equipment is hindered. Computer Generated-Hologram (CGH) is commonly utilized as null for testing cylindrical optics. However, since the fabrication process of CGH with large aperture is not sophisticated yet, the null test of cylindrical optics with large aperture is limited by the aperture of the CGH. Hence CGH null test combined with sub-aperture stitching method is proposed to break the limit of the aperture of CGH for testing cylindrical optics, and the design of CGH for testing cylindrical surfaces is analyzed. Besides, the misalignment aberration of cylindrical surfaces is different from that of the rotational symmetric surfaces since the special shape of cylindrical surfaces, and the existing stitching algorithm of rotational symmetric surfaces can not meet the requirements of stitching cylindrical surfaces. We therefore analyze the misalignment aberrations of cylindrical surfaces, and study the stitching algorithm for measuring cylindrical optics with large aperture. Finally we test a cylindrical mirror with large aperture to verify the validity of the proposed method.

The precision of traditional squareness measurement on ultra-precision motion stage is mostly determined by the standard component, such as bare L-square and optical pentaprism, and the measurement precision is lower than the precision of the standard component. Based on the error separation, this paper presents a novel method of squareness measurement with an optical square brick. The angles between the guide and the four lines of the section of the brick are measured, and the squareness error distraction is achieved by the truth that the internal angle sum of a tetragon is 360°. A squareness measurement test is carried out on the coordinate measuring machine (CMM) by using an optical square brick with the squareness error of 0.3°. The results show that the local squareness and uncertainties between the X axis and Y axis of the CMM are 2.5arcsec and 0.5arcsec respectively. The measurement precision is higher than the precision of the brick and the feasibility and accuracy of the method are validated.

For traditional dual-plane on-axis digital holography, the robustness is lower because it is difficult to maintain the stability of the phase difference between the object beam and the reference beam, and it may be invalid when the objects are on the surface of a medium with uneven thickness. An improved dual-plane digital holographic method based on Mach–Zehnder interferometer is presented to address these problems. Two holograms are recorded at two different planes separated by a small distance. Then, the zero-order image and conjugated image are eliminated by Fourier domain processing. In order to enhance the robustness of the system, the object is illuminated by a stochastic beam that is a speckle wave produced by a diffuser. Simulated and experimental results are shown to demonstrate that the proposed method has greater robustness than the traditional dual-plane on-axis digital holography and it can be used to imaging on the irregular surface of a transparent medium.

Compound eye has the merits of large FOV (Field of View), high acuity to motion and compact structure. In order to achieve large FOV, most natural compound eyes have curved structures. However, a 3D microlens array alone cannot work properly with a planar image sensor, as a result, very complex relay optical design is required for beam-steering and image formation. On the other hand, artificial compound eyes with planar structure are easy to design and fabricated, but the field of view is very small. To address this issue, an innovated design is presented in this paper. The system comprises of a planar structured microlens array and two curved folded mirrors. A very high fill factor can be achieved by using planar microlens array. The design was verified with Zemax simulation and preliminary experiment. The results show that the system can achieve large FOV imaging without significant lens distortion and ghost image, demonstrating the feasibility and flexibility of the proposed method.

The mounting design of a reference surface for a 6-in transmission sphere is presented in this paper. To achieve highprecision measurement in interferometry, the reference wavefront error should be controlled within peak-to-valley (PV) 0.1 λ (λ=0.6328 um) for subtraction in calibration. The reference wavefront error includes the system aberration error and the irregularity of the reference surface. When a transmission sphere is well aligned, the reference wavefront error is dominated by the reference surface. The mounting of the reference surface is imperative because the surface deformation of the reference surface after mounting needs to be lower than 0.1 λ. Besides the mounting deformation, self-weight deformation is also considerable for large optics, such as 6-in reference surface in our study. Consequently, a semikinematic mounting is applied using three small contact areas to avoid over constraint. The transmission sphere in our study is vertically tested on QED aspheric stitching interferometer (ASI), and then the trefoil aberration is occurred. There are two methods to decrease surface deformation after mounting, including deformation correction using computer control optical surfacing (CCOS) and adding soft supporting between hard mounting. In this study, three soft supports are used to share the loads of three rigid supports and then to minimize surface deformation due to gravity. Mounting design and experiments are described in this paper. Finally, the reference wavefront error of the prototype is successfully restrained within 0.1 λ in measurement.

Lithography projection objective is one of the most precise optical systems in optical manufacture field. The required accuracy of the asphere in the objective is down to nanometer and sub-nanometer, which is a great challenge for optical fabrication and testing. In this paper, the theories and technologies of sub-nanometer asphere fabrication and testing are studied and developed. Combined the sub-nanometer interference testing method and atom level polishing technologies, sub-nanometer aspheres are realized. Two kinds of testing methods are used for the measurement of the asphere and the difference of the results is less than 1nm (RMS).

With the rapid development of high-speed and heavy-load in modern rail transit, the abrasion and surface defect of rail are getting serious, and the demand of measuring the rail shape and surface defect has been rising. Phase Measuring Profilometry (PMP), due to the good characters of non-contact, high precision, easy to control automatically etc., is often used for precise 3D shape reconstruction. In this paper, PMP technology and Stoilov phase shift algorithm are adopted, three deformed fringe patterns of rail are collected with fixed phase shift between them, and branch cut phase unwrapping algorithm is used, based on which the three-dimensional surface shape of the rail is reconstructed and the artificial surface flaws are restored and measured. This method provides a good reference for the precise online detection of the rail abrasion and surface defect.

In Phase Measurement Profilometry(PMP), the setting of the reference plane plays an important role. It is a critical step to capture the grating fringe projected onto the reference plane in PMP. However, it is sometimes difficult to choose and place the reference plane in practical applications. In this paper, a virtual reference plane is introduced into PMP, with which 3D measurement can be realized without using the physical reference plane. The virtual reference plane is generated through extracting a partial area of the deformed fringe image that corresponds to a planar region and employing the interpolation algorithm. The method is proved theoretically through simulation experiments, providing a new suggestion for actual measurement by PMP.

As the most important core part of stereo vision, there are still many problems to solve in stereo matching technology. For smooth surfaces on which feature points are not easy to extract, this paper adds a projector into stereo vision measurement system based on fringe projection techniques, according to the corresponding point phases which extracted from the left and right camera images are the same, to realize rapid matching of stereo vision. And the mathematical model of measurement system is established and the three-dimensional (3D) surface of the measured object is reconstructed. This measurement method can not only broaden application fields of optical 3D measurement technology, and enrich knowledge achievements in the field of optical 3D measurement, but also provide potential possibility for the commercialized measurement system in practical projects, which has very important scientific research significance and economic value.

Nanotechnology is the science and engineering that manipulate matters at nano scale, which can be used to create many new materials and devices with a vast range of applications. As the nanotech product increasingly enters the commercial marketplace, nanometrology becomes a stringent and enabling technology for the manipulation and the quality control of the nanotechnology. However, many measuring instruments, for instance scanning probe microscopy, are limited to relatively small area of hundreds of micrometers with very low efficiency. Therefore some intelligent sampling strategies should be required to improve the scanning efficiency for measuring large area. This paper presents a Gaussian process based intelligent sampling method to address this problem. The method makes use of Gaussian process based Bayesian regression as a mathematical foundation to represent the surface geometry, and the posterior estimation of Gaussian process is computed by combining the prior probability distribution with the maximum likelihood function. Then each sampling point is adaptively selected by determining the position which is the most likely outside of the required tolerance zone among the candidates and then inserted to update the model iteratively. Both simulationson the nominal surface and manufactured surface have been conducted on nano-structure surfaces to verify the validity of the proposed method. The results imply that the proposed method significantly improves the measurement efficiency in measuring large area structured surfaces.

Freeform has been widely applied in both imaging optics and non-imaging optics. Optical freeform surfaces can be fabricated by ultra-precision machining process. The geometrical errors of these freeform optics can be measured by contact or non-contact approaches. Imaging quality is one of the major criteria for imaging optics, while illumination distribution and energy efficiency are the important performance parameters for non-imaging optics. It is necessary and helpful to relate the geometrical errors and the optical performance of the freeform optics, so as to provide a well balance between the machining accuracy and efficiency. This paper surveys the current research on the relationship between optical performance and geometrical errors of optical surfaces, including the research work for the measurement of geometrical errors of freeform surfaces, and the valuation of optical performance. It shows that there is still a lack of research work undertaken to quantitatively analyze the relationship between the optical performance and geometrical errors. Therefore, it is interesting to carry out some future work on the quantitative analysis of the relationship between specific optical parameters and certain frequency surface errors.

Our study proposes a method of polarization mode dispersion (PMD) under the influence of optical signal-to-noise-ratio (OSNR) in the two-dimensional phase diagram, while the polarization mode dispersion (PMD) and optical signal-to-noise-ratio (OSNR) exist at the same time, using the controlling variable method. The study is based on 0.25 bit period delay sampling in NRZ-DPSK system, the range of the experimental optical signal-to-noise-ratio (OSNR) is from 10dB to 30dB, polarization mode dispersion (PMD) is from 0 to 20ps√km . The results show that the method can get the linear variation of polarization mode dispersion (PMD) in the two-dimensional phase diagram.

The self-calibration method for angle measurement is introduced, and the optimal arrangement of several equal distance distribution groups of reading heads was proposed to realize highly effective restraint of the specified Fourier components of angular measuring deviation in loosely restricted environment. Base on this method, a self-calibration angle encoder system was developed using micro reading heads, glass scale disc, air bearing, and multi-channel counter. According the method of examination of the angular measuring standard, the metrological performance of the system was evaluated using national angle standard of China. The evaluation result revealed that the measuring deviation is within ±1.5″, the measuring repeatability is less than 1.1″. Referring to the verification scheme of measuring instrument for plane angle, the system can be used to calibrate the angular measuring instrument with max permissible error worse than ±4.5″in situ.

It is difficult for the traditional self-calibration algorithm to achieve high precision calibration when measuring over a wide range. To overcome this shortcoming, an improved self-calibration algorithm for multilateration coordinates measuring system is proposed. Different from the traditional self-calibration algorithm, the improved algorithm preselect certain calibration points which is fixedly mounted on stable base, the lengths between specific points are measured precisely by laser interference method. Then the precise lengths are taken as a part of optimization objective function, and then the system parameters are determined by iterative computation. The effectiveness of the proposed algorithm is verified by simulations and experiments. The results show that by using the improved algorithm, the max error is only 8.9μm, the improved algorithm helps to improve the accuracy of the multilateration system significantly.

In order to develop an aspheric surface measurement standard device to provide reliable and traceable measurement and calibration, a high resolution aspheric surface measurement technology based on laser interferometer is proposed in this paper. A laser interferometer with frequency stabilized He-Ne laser is used to provide traceable measurements. The standard device would provide calibrations for different kinds of aspheric surface, therefore the interferometer used in the standard device would be influenced by various factors, such as roughness, reflectivity, material and slope angle. The influences of reflectivity and roughness are analyzed. A compensation method based on the analysis is applied in the signal processing system to reduce the influences of reflectivity and roughness. An objective lens is used to collect the measurement beam reflected from the target. The laser interferometer is set up and tested under different conditions: the reflectivity is 1%~100%, the surface roughness is 0.012~0.8μm. Experimental results show that the measurement resolution of the developed interferometer is at the nanometer level.

It is often difficult to monitor the subgrade performance of an in service highway structure due to its depth and large in size. Traditional sensors for pavement performance monitoring are usually point-wise sensors and therefore cannot fulfill the requirement for large coverage. This paper introduces a shape measurement sensor based on Fiber Bragg Grating (FBG) sensing technique for pavement structure developed by our research group. It can provide large-scale layer shape measurement using only one FBG sensing element and can bear the high compaction force and high temperature during pavement construction. The proposed sensor has been test in lab to show high accuracy in measurement. In the construction of the He-da highway in Jilin province, the proposed sensor has been applied to monitor the subgrade performance for the first time. Ten sets of the sensors with individual length of about 15 m have been embedded and the performance data have been collected twice. The embedding process and monitoring data will be introduced and discussed. The results have shown the potential of the proposed sensor for future large scale application.

It is hard to get high-precision measurement of the radius of curvature (ROC), because of many factors that affect the measurement accuracy. For the measurement of long radius of curvature, some factors take more important position than others'. So, at first this paper makes some research about which factor is related to the long measurement distance, and also analyse the uncertain of the measurement accuracy. At second this article also study the influence about the support status and the adjust error about the cat’s eye and confocal position. At last, a 1055micrometer radius of curvature convex is measured in high-precision laboratory. Experimental results show that the proper steady support (three-point support) can guarantee the high-precision measurement of radius of curvature. Through calibrating the gain of cat's eye and confocal position, is useful to ensure the precise position in order to increase the measurement accuracy. After finish all the above process, the high-precision long ROC measurement is realized.

Phase-shifting Point Diffraction Interferometer (PSPDI) utilizing nearly perfect spherical wavefront diffracted by a pinhole as reference wavefront, which diminishes the influence of reference optics used in traditional interferometers, has been developed with high accuracy, repeatability and reproducibility. Accuracy of PSPDI is mainly limited by the quality of diffracted reference wavefront. We analyze the quality of diffracted reference wavefront by using of Rayleigh- Sommerfeld diffraction theory and performed FDTD numerical simulation. Based on analysis, we have developed a phase-shifting point diffraction interferometer. Ultra-precise pinhole alignment technical, high stable mount, high stable testing environment and error source insensitive data processing algorithm was used to achieve high stability and accuracy. Via accuracy evaluation, a deep sub-nanometer system error of developed PSPDI is obtained. A cross comparison of PSPDI measurement and measurement of another kind of interferometer was done, and the difference was 0.16nmRMS. The developed PSPDI has been applied in spherical mirror testing and EUV projection objective testing.

The dynamics behavior of spiral patterns is investigated in gas discharge using optical method. Rich kinks of spiral patterns are obtained and the formation and evolution process is investigated. The process of pattern formation is breakdown → hexagon → bee comb-like → strip → spiral → chaos. Spiral pattern always formed after the strip pattern. It is found that the temperature of the water electrodes plays an important role in the spiral patterns formation. When it exceeds 20°C no spiral has been obtained. The discharge current waveform and the emission spectrum of the discharge have been measured when the filaments self-organized in spiral pattern. Electron excited temperature of forming spiral pattern is calculated using intensity ratio method. It is found that the electron excited temperature of spiral pattern increase as the power supply frequency increased. Relation between wavelength and discharge parameter has been measured. It shows that the wavelength of spiral pattern increases as the discharge gap increases, and decreases as the air ratio mixed in argon increases. Accompanying measurements proved that the wavelength is approximately linear to the square root of the spiral rotating period .This work has useful reference value for studying pattern dynamics.

The optical surface deviation of the lens can directly affect the quality of the optical system. In order to improve efficiency and accuracy of optical surface detection, an on-line testing system for optical surface based on polarizing coherent technology is designed and developed. No lying walls are required for the lens. In other words, they can be checked out the deviation of radius of curvature and astigmatism online. Based on the Tyman-Green interference light path, the system joins the polarization interference measuring technology. This paper makes a theoretical derivation and ZEMAX software simulation on the light path, sets up the experimental light path of the system. At last, comparison on image of Tyman-Green interference technology, the contrast of interference fringe image is improved significantly after joining polarizing coherent technology. And background noise and stray light are significantly reduced. It provides the foundation for improving the precision of image processing.

Free-form optics have a wide range of applications since they can simplify the structure of an optical system, meanwhile significantly improving the system performance. Compared to optics with traditional profiles, optical testing for freeform surface is more difficult. Although a laser interferometer can reach the surface measurement precision in nanometer scale, it has problems of a limited measurement range, a complex system configuration and relatively high requirements of working conditions. Fringe reflection technique (FRT) is gradually becoming a powerful tool for free-form surface testing owing to its advantages of simple system structure, high measurement accuracy, large dynamic range, etc. However, multiple groups of fringe images are required to display in two orthogonal directions respectively during the FRT measurement to obtain the corresponding surface gradient information. It hinders the fast detection of free-form surface to a certain extent. In order to overcome the above shortcoming, a phase retrieval algorithm based on color-frequency encoding for FRT is proposed in this paper, which can achieve the absolute phase meanwhile reducing the required number of fringe images for measurement. Experimental results demonstrate the effectiveness of the proposed method.

As one kind of light source simulation devices, spectrally tunable light sources are able to generate specific spectral shape and radiant intensity outputs according to different application requirements, which have urgent demands in many fields of the national economy and the national defense industry. Compared with the LED-type spectrally tunable light source, the one based on a DMD-convex grating Offner configuration has advantages of high spectral resolution, strong digital controllability, high spectrum synthesis accuracy, etc. As a key link of the above type light source to achieve target spectrum outputs, spectrum synthesis algorithm based on spectrum matching is therefore very important. An improved spectrum synthesis algorithm based on linear least square initialization and Levenberg-Marquardt iterative optimization is proposed in this paper on the basis of in-depth study of the spectrum matching principle. The effectiveness of the proposed method is verified by a series of simulations and experimental works.

Laser range finder has been equipped with all kinds of weapons, such as tank, ship, plane and so on, is important component of fire control system. Divergence angle is important performance and incarnation of horizontal resolving power for laser range finder, is necessary appraised test item in appraisal test. In this paper, based on high accuracy test on divergence angle of laser range finder, divergence angle test system is designed based on CCD imaging, divergence angle of laser range finder is acquired through fusion technology for different attenuation imaging, problem that CCD characteristic influences divergence angle test is solved.

Infrared thermal imaging system generates image based on infrared radiation difference between object and background and is a passive work mode. Range is important performance and necessary appraised test item in appraisal test for infrared system. In this paper, aim is carrying out infrared system range test in laboratory , simulated test ground is designed based on object equivalent, background analog, object characteristic control, air attenuation characteristic, infrared jamming analog and so on, repeatable and controllable tests are finished, problem of traditional field test method is solved.

Visible-light reconnaissance device based on CCD is applied to all kinds of weapons, CCD cannot work because of saturation when it faces intense light. Sun is intense light source in nature and assignably influences CCD performance. In this paper, aim is appraising CCD anti-sunlight ability, object reflection characteristic test system is designed, based on typical background reflection characteristic including grant, sand and so on, complex circumstance is formulated and test project is optimized with orthogonal design method, problem that is without test technology on CCD anti-sunlight jamming is solved.

A longitudinal electron bunch diagnostics system is developing to measure the longitudinal bunch charge distribution for the new IRFEL at National Synchrotron Radiation Laboratory (NSRL). We use a Martin-Puplett interferometer, which is essentially a Michelson interferometer, to measure the spectrum of the coherent transition radiation produced by electrons through a thin metallic foil. Frequency components of coherent transition radiation have a relationship with the bunch form factor, which is described by the square modulus of the Fourier transform of the bunch distribution. Then several techniques, including a Kramers-Kronig analysis, have been applied to determine the longitudinal bunch charge distribution. The details of the design and theoretical investigation will be described in this paper.

When the meteorological satellite exploring geospace, it is necessary to confirm the imager attitude in inertial coordinate system in order to calculate the geographic situation of imaging target. In this paper, the calibration methods of the space coordinate system are described. The transformation matrix characteristics in the various methods are compared. At last the transformation matrix between aurora imager coordinates and satellite coordinates is measured by an efficient method. The results show that the calibration accuracy of the method is better than 1 arc second.

The high-efficiency simulation test of military weapons has a very important effect on the high cost of the actual combat test and the very demanding operational efficiency. Especially among the simulative emulation methods of the explosive smoke, the simulation method based on the particle system has generated much attention. In order to further improve the traditional simulative emulation degree of the movement process of the infrared decoy during the real combustion cycle, this paper, adopting the virtual simulation platform of OpenGL and Vega Prime and according to their own radiation characteristics and the aerodynamic characteristics of the infrared decoy, has simulated the dynamic fuzzy characteristics of the infrared decoy during the real combustion cycle by using particle system based on the double depth peeling algorithm and has solved key issues such as the interface, coordinate conversion and the retention and recovery of the Vega Prime’s status. The simulation experiment has basically reached the expected improvement purpose, effectively improved the simulation fidelity and provided theoretical support for improving the performance of the infrared decoy.

Technology of near-infrared single photon detection is used in quantum communication, laser ranging and weak light detection. Present single photon detectors are usually expensive and bulky. To overcome their disadvantages, a hand-held single photon detector based on InGaAs/InP avalanche photo diode (APD) is developed. A circuit program for temperature control and bias voltage is offered. The gating signal is generated and the avalanche signal is extracted by FPGA. Experiment results show that, the single photon detector yields only 8.2×10^-6/ns dark count rate (DCR) when photon detection efficiency is 12%, and the maximum photon detection efficiency of 16% is obtained at temperature of -55°C.

Subaperture stitching is often adopted when measuring large size optic with interferometry method. To reduce the error of defocus in the process of stitching, an improved subaperture stitching method which can eliminate the high-order defocus error is presented based on the experimental study of defocused wavefront. Through detecting the wavefront difference with variable defocus, the actual defocus wavefront is proposed to replace the traditional paraboloid defocus basement so as to realize eliminating high-order defocus. A reflector sample is tested, the roughness parameter Ra is 1.252nm and 0.403nm respectively using the paraboloid and the actual decocus wavefront as the basement. The amendatory defocus basis is taken into the subaperture stitching process, for the two subaperture wavefront, different area of the actual defocus wavefront is used. A SiC super-smooth surface is measured with the improved subaperture stitching method, the Ra is 0.236nm after eliminating high-order defocus. Results show that it is a useful way to erase high-order defocus error without changing the low frequency information of test wavefront.

In order to investigate the biological aerosols in the atmosphere, we have designed an ultraviolet laser induced fluorescence lidar based on the lidar measuring principle. The fluorescence lidar employs a Nd:YAG laser of 266 nm as an excited transmitter, and examines the intensity of the received light at 400 nm for biological aerosol concentration measurements. In this work, we firstly describe the designed configuration and the simulation to estimate the measure range and the system resolution of biological aerosol concentration under certain background radiation. With a relative error of less than 10%, numerical simulations show the system is able to monitor biological aerosols within detected distances of 1.8 km and of 7.3 km in the daytime and nighttime, respectively. Simulated results demonstrate the designed fluorescence lidar is capable to identify a minimum concentration of biological aerosols at 5.0×10^-5 ppb in the daytime and 1.0×10^-7 ppb in the nighttime at the range of 0.1 km. We believe the ultraviolet laser induced fluorescence lidar can be spread in the field of remote sensing of biological aerosols in the atmosphere.

The dual-wavelength retinal image registration is one of the critical steps in the spectrophotometric measurements of oxygen saturation in the retinal vasculature. The dual-wavelength images (570 nm and 600 nm) are simultaneously captured by dual-wavelength retinal oximeter based on commercial fundus camera. The retinal oxygen saturation is finally measured after vessel segmentation, image registration and calculation of optical density ratio of the two images. Because the dual-wavelength images are acquired from different optical path, it is necessary to go through image registration before they are used to analyze the oxygen saturation. This paper presents a new approach to dual-wavelength retinal image registration based on vessel segmentation and optic disc detection. Firstly, the multi-scale segmentation algorithm based on the Hessian matrix is used to realize vessel segmentation. Secondly, after optic disc is detected by convergence index filter and the center of the optic disc is obtained by centriod algorithm, the translational difference between the images can be determined. The center of the optic disc is used as the center of rotation, and the registration based on mutual information can be achieved using contour and gray information of vessels through segmented image. So the rotational difference between the images can be determined too. The result shows that the algorithm can provide an accurate registration for the dual-wavelength retinal image.

The stylus profiler is a conventional instrument in surface topography measurement. The interferometric stylus profiler which uses cylindrical phase grating as standard obtains the surface topography information via measuring the changes of phase. In this way, it is apt to realize wider range, higher accuracy and higher resolution simultaneously in topography measurement. Currently, cylindrical phase grating is ordinarily fabricated by means of holographic record. Subject to the present method and technics, the microstructure parameters of the grating, such as spatial frequency, groove depth and duty cycle can hardly been uniform in every area of grating. Concerning the working principle of interferometric stylus profiler with cylindrical phase grating as sensor, the quality of cylindrical hologram phase grating (80mm in radius of curvature, 1200lp/mm in center spatial frequency) is analyzed comprehensively in this paper. Effects of the inconsistency distribution of microstructure parameter of grating over cylinder surface on the phase difference between ±1st order diffraction wave-fronts in different incidence angle are discussed in detail. The theoretical analysis and numerical calculation results show that: the holographic recording parameters determine the distribution of spatial frequency of cylindrical hologram phase grating; the inconsistency of spatial frequency on the cylinder surface is the primary cause affecting measurement accuracy; the inconsistency of duty cycle of grating will have influence on measurement accuracy when the incidence angle is not equal to zero (i.e.in a small incidence angle). Therefore, the process tolerances of cylindrical phase grating are presented and a new fabrication method of high precision cylindrical phase grating is proposed.

The blur due to the rapidly relative motion between scene and camera during exposure has the well-known influence on the quality of acquired image and then target detection. An improved coded exposure is introduced in this paper to remove the image blur and obtain high quality image, so that the test accuracy of the surface defect and edge contour of motion objects can be enhanced. The improved exposure method takes advantage of code look-up table to control exposure process and image restoration. The restored images have higher Peak Signal-to-Noise Ratio (PSNR) and Structure SIMilarity (SSIM) than traditional deblur algorithm such as Wiener and regularization filter methods. The edge contour and defect of part samples, which move at constant speed relative to the industry camera used in our experiment, are detected with Sobel operator from the restored images. Experimental results verify that the improved coded exposure is better suitable for imaging moving object and detecting moving target than the traditional.

Multi-view vision technology is use of multiple images to reconstruct three-dimensional (3D) information of the research object, and the images were captured with more than two cameras from different angles. This technology has the advantages of high efficiency, simple structure and low cast. It is very suitable for on line noncontact product test and quality control. The existent multi-view vision technology is focus on the visible information, thus it is easy to be influenced by the testing environment (weather, background, light etc.), so it’s application field has some limitations. However, in the field of medical diagnostic technology, infrared vision technology reflects its advantages, like determining whether the tissue lesions by observe certain parts temperature distribution of the body. This paper is studied on infrared Multi-vision which is based on visible binocular vision theory. Firstly, obtained the intrinsic parameter and external parameter of each infrared thermal imager by Zhang’s calibration method; Secondly, taken infrared images from different angles, then combined the infrared images two by two to do feature point detecting and matching in order to find the points to be reconstructed; Finally, reconstructing 3D profile information based on calculating point clouds of the spatial coordinates.

In the field of modern optical measurement, the center thickness is a basic parameter of the optical lens, which will directly, affects the accuracy of the lens’ focal length and other optical parameters, and these parameters have great influence on overall performance of the optical system. Therefore center thickness requires precision test. Nowadays, the methods include contact measurement and non-contact measurement. Generally speaking, the center thickness of the lens with no hole in the center only could be measured through the both methods. The lens with a hole in the center is used widely, on the basis of principle of contact measurement, a method of measuring center thickness of the lens with a hole is proposed. A sign convention about radius and sagitta of curvature is defined and the geometrical expressions are derived in detail. Analyses and simulations between the errors of center thickness and variables are shown. To prove the right of the method, an experiment is done in use of a lens with no hole in the center. The results of indirect and direct measurements are presented, respectively. In comparison of direct measurement, the proposed method has a high precision.

In the field of optical metrology, luminous flux is an important index to characterize the quality of electric light source. Currently, the majority of luminous flux measurement is based on the integrating sphere method, so measurement accuracy of integrating sphere is the key factor. There are plenty of factors affecting the measurement accuracy, such as coating, power and the position of light source. However, the baffle which is a key part of integrating sphere has important effects on the measurement results. The paper analyzes in detail the principle of an ideal integrating sphere. We use moving rail to change the relative position of baffle and light source inside the sphere. By experiments, measured luminous flux values at different distances between the light source and baffle are obtained, which we used to take analysis of the effects of different baffle position on the measurement. By theoretical calculation, computer simulation and experiment, we obtain the optimum position of baffle for luminous flux measurements. Based on the whole luminous flux measurement error analysis, we develop the methods and apparatus to improve the luminous flux measurement accuracy and reliability. It makes our unifying and transferring work of the luminous flux more accurate in East China and provides effective protection for our traceability system.

The low light level and infrared color fusion technology has achieved great success in the field of night vision, the technology is designed to make the hot target of fused image pop out with intenser colors, represent the background details with a nearest color appearance to nature, and improve the ability in target discovery, detection and identification. The low light level images have great noise under low illumination, and that the existing color fusion methods are easily to be influenced by low light level channel noise. To be explicit, when the low light level image noise is very large, the quality of the fused image decreases significantly, and even targets in infrared image would be submerged by the noise. This paper proposes an adaptive color night vision technology, the noise evaluation parameters of low light level image is introduced into fusion process, which improve the robustness of the color fusion. The color fuse results are still very good in low-light situations, which shows that this method can effectively improve the quality of low light level and infrared fused image under low illumination conditions.

The fusion of low light level and infrared images can synthesize the advantages of low light level imaging and infrared imaging, to make the details of the scene and targets richer. The quality of low light level and infrared images are the prerequisites to ensure the quality of fused image. The quality of low light level image is vulnerable to target contrast, light distribution and environmental illumination, especially under low illumination, low light level image noise significantly increased, image quality degradation, but the infrared image is not influenced by environmental illumination. In this paper, the influence of low light level image quality on low light level and infrared image fusion was analyzed from several aspects, such as target contrast, light distribution and ambient illumination, which can analysis the quality of low light level and infrared fused image.

Organic photoelectric materials have showing a wide application prospect in the fields of energy, environment, information and biology because of their unique advantages. However, it is still not clear for us to understand some basic photo-physical processes (i.e. energy transfer, charge transfer, charge separation and recombination, etc.), which has affected the performance of materials and devices. This is very incompatible with the rapidly growing demand of the organic photoelectric materials and devices, and it has been one of the core problems that constraints the further applications of organic photoelectric materials and devices. The lack of the necessary systems and means is a major reason. Thus, it is a very necessary urgent task to develop new methods and technologies to evaluate the photo-physical properties of organic photoelectric materials and equipment systems. In this paper, an on-line research system for photo-physical properties is established to detect the intrinsic character of the organic photoelectric materials and devices, which integrates the fabrication instrument of the film materials and devices with the online measuring equipment combing with the high vacuum technology and the steady state transient spectrum measurement. A standard OLED device was fabricated and the electrluminescence spectra, current density, brightness, current efficiency and the power efficiency were got using this system avoiding the affect of the air and water. The results indict this system not only plays an important promoting role for the theoretical research of organic photoelectric materials and devices, but also helps improving the research level of organic photoelectric materials and devices. This work is expected to produce some potential innovating results with the international advanced level and make contributions to needs of national strategy.

This paper introduced the method of alignment and measurement for back-end optical system of quantum communication ground station. The alignment methods of important components of system such as 20 constriction multiplicator, single photon detector mechanism and so on were introduced at first. The alignment method of the key receiving optical path and the entanglement receiving optical path which were integrated into coaxial multi optical path with other three optical paths were described in detail. Finally the back-end optical system was tested indoors with an optical power meter and a collimator. The results shows that the quantum key signal (@850nm) receiving efficiency is 27.6%, the average polarization contrast is better than 320:1, the receiving efficiency of quantum entanglement signal (@810nm) was 28.6%, and the average polarization contrast is better than 180:1.

CMOS image sensors rival CCDs in domains that include strong radiation resistance as well as simple drive signals, so it is widely applied in the high-energy radiation environment, such as space optical imaging application and video monitoring of nuclear power equipment. However, the silicon material of CMOS image sensors has the ionizing dose effect in the high-energy rays, and then the indicators of image sensors, such as signal noise ratio (SNR), non-uniformity (NU) and bad point (BP) are degraded because of the radiation. The radiation environment of test experiments was generated by the ⁶⁰Co γ-rays source. The camera module based on image sensor CMV2000 from CMOSIS Inc. was chosen as the research object. The ray dose used for the experiments was with a dose rate of 20krad/h. In the test experiences, the output signals of the pixels of image sensor were measured on the different total dose. The results of data analysis showed that with the accumulation of irradiation dose, SNR of image sensors decreased, NU of sensors was enhanced, and the number of BP increased. The indicators correction of image sensors was necessary, as it was the main factors to image quality. The image processing arithmetic was adopt to the data from the experiences in the work, which combined local threshold method with NU correction based on non-local means (NLM) method. The results from image processing showed that image correction can effectively inhibit the BP, improve the SNR, and reduce the NU.

Parallel binocular stereo vision system is a special form of binocular vision system. In order to simulate the human eyes observation state, the two cameras used to obtain images of the target scene are placed parallel to each other. This paper built a triangular geometric model, analyzed the structure parameters of parallel binocular stereo vision system and the correlations between them, and discussed the influences of baseline distance B between two cameras, the focal length f, the angle of view ω and other structural parameters on the accuracy of measurement. This paper used Matlab software to test the error function of parallel binocular stereo vision system under different structure parameters, and the simulation results showed the range of structure parameters when errors were small, thereby improved the accuracy of parallel binocular stereo vision system.

The incoherent digital holography makes it possible to record holograms under incoherent illumination, which lowers requirement for the coherence of light sources and results in expanding its application to white-light and fluorescence illuminating circumstances. The Fresnel Incoherent Correlation Holography (FINCH) technology achieves diverging the incident beam and shifting phase by mounting phase masks on the phase modulator. Then it obtains holograms with phase difference and reconstructs the image. In this paper, we explain the principles of the FINCH technology, and introduce the n-step phase-shifting method which is utilized to eliminate the twin image and bias term in holograms. During the research, we studied what impact the term n may have on imaging performance, compared imaging performances when different phase masks are mounted on SLM, and established simulation system on imaging with which imaging performances are deeply inspected. At last, it is shown in the research that the FINCH technology could record holograms of objects, from which clear images could be reconstructed digitally.