This PDF file contains the front matter associated with SPIE Proceedings Volume 12559, including the Title Page, Copyright information, Table of Contents, and Conference Committee listings.

The mechanical structure of space remote sensor with large pupil would be distorted on ground because of the gravity. The distortion would directly affect the sensor performance. According to this demand, a high precision measurement of distortion is presented in this article. It is based on the theory of interference. Tow mirrors are placed on the positions according to the measurement requirement. One is the reference mirror and the other is to measure the movement. They are all spherical mirrors, and are aligned with a common center. A spherical wave is centered with them an reflected by the mirrors, when the distortion occurs, position of the two mirrors is changed, so does the fringe of the interference. The mathematical equation between distortion and fringe changing is presented. The precision can be less than 1μm.

The technique of tagging lapping and polishing slurries with fluorescent material is a promising subsurface damage (SSD) detection method for detecting SSD of optical component and perceiving its formation. However, currently only CdSe/ZnS QDs, CdSSe/ZnS QDs and Rhodamine 6G (R6G) were used to detect SSD, the feasibility of other types of QDs for SSD detection is not been analyzed in detail. And compared with QDs, R6G have a lower fluorescence intensity and is prone to photobleaching. Therefore, in this paper, we not only investigated the feasibility of various types of QDs for SSD detection theoretically and experimentally, but also used the anti-fluorescence quenching agent to enhance the fluorescence of R6G solution, and further studied the influence of anti-fluorescence quenching agent on the fluorescence of SSD tagged by R6G. It is found that (1) no matter how excitation intensity changes, the InP/ZnS QDs, CuInS2/ZnS QDs, R6G, R6G containing anti-fluorescence quenching agent and C QDs can be used to detect SSD; (2)CdSe/ZnS QDs can be used to detect SSD when the excitation intensity is higher than 33 mW; (3)Si QDs, Perovskite QDs, CdSe QDs, and InP QDs can’t be used to detect SSD; (4) The influence of anti-fluorescence quenching agent on the fluorescence of R6G in SSD is related to excitation intensity. This study lays a foundation for detecting the distribution and depth of SSD and perceiving the formation mechanism of SSD in brittle optical materials.

A method for designing and depositing rectangular wave broadband-pass filter is put forward after a deep study of the nature of the film-filters. A rectangular wave OD3-A broadband-pass filter sample is designed and prepared with this method, with its reference wavelength λ₀ =515nm in the working range of 400~1100nm. The average transmittance of the sample in its pass-band of λ₀ ±25nm reaches 92.7%, meanwhile the transmittance in the high-reflective bands of λ ≠ λ₀ ± 25 nm is less than 0.1%. The transmittance of the thin film sample is tested, and the spectrum meet the requirement. It turned out to be a more advanced technology of designing and depositing rectangular wave broadband-pass filter. Compared with the Fabry-Perot Interferometer narrow-band pass filters’ films which needs optical-controlling method, and the traditional film which combines short and long pass filters making the coatings very thick and with low transmittance in transition zone. it is more economical, have more wide range of transmission and the transmittance is higher in the range of pass-band.

When the Ritchey-Common method is used for high-precision surface shape detection of large-aperture plane mirrors, a reflective spherical mirror needs to be used to build the detection optical path. When building the detection optical path, the plane mirror and the spherical mirror has a large diameter and a long detection optical path, so there are various artificial adjustment errors. In order to solve the problems of high-precision surface shape detection of large-diameter plane mirrors, two common adjustment errors of eccentricity and tilt during optical path detection are analyzed. By using optical software to build a large-diameter plane mirror detection optical path model, set different eccentricity and tilt errors to obtain the system wave aberration, solve the system wave aberration data to obtain the plane mirror shape to be measured, and compare it with the preset standard surface shape. The simulation of a 2m plane mirror shows that the difference between the two Ritchey angles is in the range of 11°~30°. When the eccentricity error is controlled within 5% of the aperture and the tilt error is controlled within 1°, the surface shape recovery results are different from the standard surface RMS by the order of 10^-3λ. Based on the above error simulation analysis, the actual Φ2m plane mirror shape detection is guided, and the results show that the RMS of the plane mirror reaches 0.0238λ, and the PV is 0.1629λ (λ=0.6328um). The purpose of this paper is to reveal the influence of the optical path adjustment error on the shape of the 2m plane mirror, so as to control the error of the plane mirror shape detection of the actual large-aperture mirror.

The optical system will always be different from the design value after been processed. It is necessary to adjust the relative positions between the optical elements to improve the imaging quality of the system. However, if the elements are adjusted randomly, the alignment will be inefficient, so the computer-aided alignment method came into being. In this article, for the alignment of large aberration systems, a new fully-connected network computer-aided alignment (Fc-Net CAA) method is proposed. The systems’ wavefront errors (WFEs) are described by the Zernike polynomials which have a huge advantage in describing system aberrations and we proposed a Fc-Net model for predicting systems’ misalignment. The Fc-Net model is trained with the WFEs of thousands of randomly misaligned instances of the lens system that are modeled in the optical design software, so as to establish the relationship between the system aberrations and the amount of misalignment. In this way, the proposed Fc-Net CAA can achieve the computer-aided adjustment process for systems with large aberrations without a complicated iterative process. The off-axis three-mirror system with aspheric surfaces was simulated and adjusted. During the simulation, a single round of adjustment can make the optical system close to the design wave aberration values, and the average of the five field-of-view WFEs is enhanced from 2.4λ (RMS; λ=550nm) to 0.0764 λ (average). The simulation results verify that the improved algorithm can solve the large initial alignment error of the offaxis reflective optical system with aspheric surfaces.

Aiming at the problem of on-line real-time monitoring of grinding wheel wear state in ultra-precision grinding, the wear experimental research of fused silica optics is carried out by using acoustic emission technology. The grinding wheel wear state is determined according to the micro morphology of grinding wheel surface. On this basis, the variation law of acoustic emission signal with grinding wheel wear state is revealed, and the quantitative relationship between the root mean square value of acoustic emission signal, grinding force grinding, wheel spindle power and grinding wheel wear state is built. The wavelet packet transform is used to decompose the acoustic emission signal, studying the variation law of root mean square value of acoustic emission signal in different frequency bands under different grinding wheel wear, taking it as the feature of grinding wheel wear, and obtaining the early warning threshold for grinding wheel wear passivation according to the micro morphology of grinding wheel surface. It’s helpful to monitor and control the wear state of diamond grinding wheel in the grinding process of optics through the analysis of acoustic emission signal, so as to improve the grinding efficiency and quality of optics.

A multilateration system is a 3-dimensional coordinate measurement system, through measuring multiple distances between a target point and laser interferometry measuring instruments, with high precision and large measuring scare, which consists of three laser trackers or tracers at least. A quantifiable analysis method is proposed, for the effect of stations’ mutual position relationship on the measurement accuracy of the multilateration system. The method is based on a mathematical model which linearizes the relationship between the coordinate measurement error of the system and the distance measurement error of laser trackers. Some methods, optimizing the mutual position relationship of stations, are derived from the model, which can improve the measurement accuracy. The rationality of the methods is verified by simulations and experiments. The results show that the max error of the multilateration system improved is only 0.020mm, which is better than a laser tracker. The multilateration system, with the optimized layout of stations, has higher precision.

Based on the Fourier heat exchange equation, the heat-damage model irradiated by continuous-wave laser is developed on the basis of considering the phase transition of the material. Using the model, the temperature field in 30CrMnSi steel substrate that coated by polycarbosilane (PCS) composite coating are analyzed. And the effects of laser parameters and coating thickness on the temperature field are discussed too. The calculation results agree well with the experimental results, which can provide the theoretical basis for analyzing the laser ablation effect of laser protection material, such as PCS. The simulation results demonstrate that, the PCS composite coating provides obvious thermal protection to the 30CrMnSi steel substrate and the laser-to-target power density of continuous-wave laser has more sensitive influence on the PCS laser-proof effect.

A new lens composed of countless annular micron channels was designed, which can not only achieves high focusing efficiency but also meets the needs of lightweight and miniaturization. Aiming at maximizing focusing efficiency, the structure design of lens was analyzed, and the mathematical relationship between optical conditions such as focal length and X-ray energy and structural parameters such as channel width, curvature radius, diameter, and channel length was deduced. According to the theoretical analysis, ideally, if the channels are equally spaced, the thickness of the lens is non-linear gradient. In order to improve the feasibility of the preparation process, three types of structure approximations were carried out. The imaging performance of lenses with different structures were simulated by Monte-Carlo ray tracing method. Taking into account the focusing efficiency and the feasibility of preparation, the lens can be divided into multiple inclined or flat planes with different channel length.

A typical and widely used configuration of freeform imaging system is freeform off-axis three-mirror systems. However, as the system configuration and surface shape have no rotational symmetry, the assembly process will be very difficult. In this paper, we designed off-axis three-mirror systems in which the primary and tertiary mirrors are integrated into one single element. The two mirrors use different portions of a single mirror, which is represented by one mathematical expression. The design process of the system is demonstrated in detail, and three different kinds of light folding geometry are explored. The system design using different types of freeform surface is also explored and the imaging performance is compared. Finally, tolerance analysis which considers the local and random nature of surface error and actual manufacturing difficulty of the freeform surface is conducted.

Aiming at the application requirements of space remote sensing observation of light and small multispectral imaging technology, a wide field of view multispectral small off-axis three-mirror optical system based on linear gradient filter is designed. The spectral coverage range is 430nm ~ 900nm, the field of view is 6.3 ° × 4.5 °, F number is 8. The focal length of the optical system is 350 mm, and the system uses staring scanning to image the ground. The detector is 8424 × 6032 array detector, the pixel size is 4.6μm. The light splitter adopts linear gradient filter, and the aperture diaphragm is set at the secondary mirror, so that the size of the main mirror is close to that of the three mirrors, and the size of the whole system is reduced. Finally, the design results show that the whole system has compact structure and good imaging quality. The modulation transfer function (MTF) of the optical system in each spectrum band of the full field of view is greater than 0.3 at the Nyquist frequency of 108lp/mm. MTF and Spot Diagrams are close to the diffraction limit, which can meet the application requirements.

Aiming at the problems existing in the optical system of laser communication terminal, in order to improve the isolation level of the communication terminal, the off-axis four-mirror afocal system with ultra-long exit pupil distance used in the coude optical path laser communication terminal is studied. In this paper, the method of four-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 four-mirror afocal system is designed with an entrance pupil diameter of 100mm, a field of view of 500μrad, the operating wave band of 1.55μm, and compression ratio of 15 times. The distance of exit pupil is greater than 500mm. After assembly and adjustment, the wavefront error root mean square (RMS) value of the four-mirror afocal system is 0.0172λ(λ=1.55μm). The four-mirror afocal system in this paper can have good imaging quality, reduce the backreflection and scattering of the sensitive mirrors, and solve the contradiction between the ultra-long exit pupil distance and the ultra-large compression ratio. It has application prospect in the field of space laser communication and space gravitational wave detection.

The structure of the initial system is calculated according to the aberration theory, in which the radius of the primary mirror is 300 mm, the radius of the secondary mirror is 320 mm, the distance between the primary mirror and the secondary mirror is 90 mm, and the blocking ratio is close to 0.4, and the occlusion ratio is close to 0.4. A three-piece correction lens set is designed to solve the spherical aberration and comet aberration caused by the Cassegrain system in the large field of view, and the imaging of the edge field of view of the large field of view system is realized. Through the optimization and layout of the overall system, the MTF value of the system is finally greater than 0.4 within the frequency of 130 lp/mm. This paper provides important reference value for the design of catadioptric optical system with large aperture and large field of view.

Compared with traditional optical surfaces, freeform surfaces provide much more degrees of freedom to tailor the irradiance distributions of light sources, forming previously unimaginable illumination optical systems. However, the complexity of freeform surfaces presents a huge challenge to the design process, especially when the light source size is assignable. We achieved fast irradiance evaluation of freeform illumination lens based on deep learning methods, preparing for a rapid optimization for the lens design. These learned simulation results are similar to those of LightTools, while the computation time is greatly reduced. The representation of freeform surfaces, the generation of datasets, and the selection of neural network structures are introduced in this paper. In the future, we will further improve the neural network performance and use the back-propagation of the neural network to realize a rapid optimization of the freeform lens.

In stereo image production, because the dual lens fixed baseline optical system cannot provide the scene imaging requirements under different object distances, and the existing dual lens system baseline is designed according to the pupil distance of human eyes, the working distance is limited, so it cannot effectively obtain the scene information outside the stereoscopic range of human eyes. In order to improve the creation and artistic effect of film and television images, increase the film lens language, and obtain more 3D image information, especially improve the long-distance depth information acquisition ability of the lens, this paper studies and design the expansion of variable baseline function on the basis of retaining the existing stereo imaging advantages of dual lens system