This PDF file contains the front matter associated with SPIE Proceedings Volume 12964, including the Title Page, Copyright information, Table of Contents, and Conference Committee information.

In order to overcome the shortcomings of the aiming system in inertial confinement fusion device, such as small field of view, long preparation time and large manual interpretation error, a vision aiming system based on diffraction effect is designed. After the diffraction of the reflected light of the target, the starlight detection device is used to detect the center of the target automatically, which reduces the manual interpretation error. The system uses forward illumination to improve imaging integrity, uses quarter-wave plate and polarization splitter to improve system energy utilization, uses diffraction effect and starlight detector to improve aiming accuracy up to 9.52 μm, which reduces preparation time. The quality of illumination system and diffraction system is evaluated by using spot diagram in Zemax, and the simulation of the system is carried out. The results meet the engineering requirements.

As a kind of common aspheric element, high-gradient aspheric surface is more and more used in high-tech fields because of its advantages of improving system accuracy and optimizing system comprehensive performance. At the same time, it also has higher requirements for its surface processing quality. The trajectory planning in polishing is an important part that affects the surface quality of the component. Due to the continuous change of the curvature radius of the high-steep aspheric surface and the large change rate of the vector height, the commonly used planar equidistant grating scanning trajectory is projected onto its surface. The distribution of trajectory points on the surface is obviously uneven, resulting in over polishing or under polishing in some areas. In order to ensure the machining accuracy of high-gradient aspheric surface, the concept of “common equal arc length point” is proposed and the equal arc length trajectory point planning model is established to make the spatial distance of any adjacent trajectory points on the aspheric surface consistent, and the spatial interval change rate is introduced to quantitatively analyze the distribution of trajectory points. Several aspheric surfaces with different vector height change rates are sampled by the equal arc length trajectory point model. Under the same sampling accuracy as the plane equidistant grid scanning trajectory point model, the change rate of the trajectory point spacing to the surface shape is reduced from 70.72 % ~ 33.03 %to 25.18%~8.75 %. The simulation results show the effectiveness of the model.

Modern space optical remote sensors use many off-axis aspheric surfaces to improve performance and increase the field of view. The geometric parameters of the off-axis aspheric surface include its vertex radius of curvature and aspheric surface coefficients, which have an important influence on the performance of the remote sensor. With the continuous improvement of remote sensor performance indicators, the aspheric surface diameter and vertex radius of curvature continue to increase, and the tolerances are becoming more and more strict. Traditional geometric parameter measurement methods such as three-coordinates and compensator control cannot meet the requirements. In order to achieve high-precision measurement of geometric parameters of aspheric surfaces, a laser tracker cooperated with CGH to measure geometric parameters was researched. The structure of CGH is simple, and the optical reference is easy to accurately establish, convert and reproduce. The tracker has high measurement accuracy and wide range. Its software can model and calculate angle relationships, and can perform spatial measurement and positioning of complex optical paths with folding mirrors. Using the simple structure of CGH and the laser tracker to accurately measure the distance, the aspheric surface detection optical path high-precision positioning (0.01mm) and optical axis reference lead (5") to meet the tolerance requirements of geometric parameters. Through simulation analysis and experimental verification. The calculation accuracy of the vertex curvature radius can reach 0.01%, and the accuracy of the aspheric coefficient can reach 0.0001.

It is of strong practical significance to the management of civil aviation aircrafts through optical detection of aerial targets. A proper detection spectrum can help to enhance the target and suppress the background, guaranteeing the real-time accurate positioning and tracking of aerial targets over a wide range. Firstly, the principle of space-based air target detection is introduced. By analyzing the sources of the target radiation and background radiation, the contrast between target and background radiation intensity is determined as the evaluation standard for space-based detection. In simulations, three typical backgrounds (sea, farm and desert) and Boeing 737 aircraft were taken as examples. The apparent spectral radiance of the background in each spectral band was analyzed with the bulk and apparent spectral radiance of the aerial target under different detection conditions (detection azimuth angle, elevation angle, flight height). By traversing the 2~6 μm spectral range with a maximum spectral width of 1 μm, the contrast between target and background radiation intensity was calculated. 29 alternative spectral bands under 30 working conditions, including different flight altitudes, different backgrounds and different detection azimuth angels, were screened for the contrast between target and background radiation intensity exceeding the threshold of 2000. Considering changes in the upper and lower limit values of the contrast between the target and the background radiation intensity under each spectrum, background, target flight altitude and detection azimuth angle, the 2.53~2.54 μm spectrum could be used as one of the preferred spectral bands of the space-based aerial target optical detection system.

To improve the performance of differential transmissivity & reflectivity measurer (DFTRM) for coated mirrors with extremely low transmission or reflection loss, a novel scheme based on Fresnel formula and optical balance is demonstrated. Benefit from the characteristic of Fresnel formula, i.e., the specular reflectivity of the reference optical surface varies slowly with the incident angle near Brewster’s angle, so the precision measurement of transmissivity or reflectivity is then converted to the precision measurement of the incident angle in our two-optical-path scheme. An experimental system is set up to verify the feasibility of precision measurement, and the preliminary measurement results for high-reflectivity coated mirrors with low transmission loss prove its ability to measure transmissivity and distinguish the transmissivity difference of 10 parts per million (ppm) magnitude. Various potential error sources, including the responsivity of photodiodes, the scale factor, the polarization of the incident laser, the refractive index of the reference medium and the spatial relationship of components, are discussed qualitatively or quantitatively to provide guidance for the subsequent optimization of transmissivity & reflectivity measurer at ppm level in the future.

As an important trend in future display technology, Micro-LED has significant advantages in brightness and contrast, as well as better color performance and response speed. Micro-LED and related display technologies have attracted increasing attention from the academic community in recent years. However, Micro-LEDs with Lambertian emission patterns cannot be directly used in projection displays. Therefore, complex relay optics are often required to collimate the emission light, increasing the system complexity. This paper proposes a novel Micro-LED structure that combines with meta surfaces on top of the Micro-LED. This structure can optically control the light field of Micro-LED into a highly collimating one from the originally Lambertian distribution. Compared with the initial Micro-LED structure, this configuration has good light emission characteristics with primary light concentration between 10 degree intervals. The designed structure has the light distribution with the full width at half maximum (FWHM) angle ±5.48°. At the same time, compared with the traditional Micro-LED structure, its center light intensity is increased to 21.98 times the original. This structure optimizes and improves the performance of Micro-LED in the field of projection display.

The continuous exploration of the ocean boosts an increasing use of optical means to guide underwater object grasping or underwater docking. In this paper, an underwater wide working distance lens is designed, which is suitable when accurate guidance by machine vision at close range is needed. The lens is adaptable for underwater manipulator grabbing the target, docking of unmanned underwater vehicles and so on. The commonly used sonar guidance methods for underwater long-distance work are difficult to meet the accuracy of close-range work. The method of optical guidance is also affected by factors such as water's absorption and scattering of light, and can only work at close distances. Combining the limitations of both, the designed working distance of this system is within the range of 0.1-10 m, and the use of polarization can further improve the effectiveness of underwater imaging. In view of the effects of seawater refractive index, water pressure, total length limit, and water temperature in the seawater use environment, this paper designs an underwater lens with the maximum working depth of 1500 meters and the working water temperature of 0-30 degrees. The lens is designed with flat underwater optical window and 10 spherical elements in 8 groups. The diagonal field of view (FoV) in water is 35 degrees, F-number (F/#) of 1.8, and the total length is less than 70mm, which is used with the polarization image sensors of 2/3inch optical format. The good imaging quality of the lens satisfies the MTF greater than 0.4@145lp/mm in the whole working distance.

Aiming at the problems of poor safety, reliability and assembly consistency of manual assembly of large segmented optical components, a dual manipulator automatic assembly method is proposed. First of all, a modular automatic assembly system is built, and the interactive cooperation mode of dual robotic arms is adopted to realize the function exchange of the two robotic arms and meet the requirements of a wider and larger visual identification and assembly range. Then, the 3D spatial grasping and assembly relationship is established by the “point cloud stitching” technology based on marker points, and the system calibration is completed. Finally, a “step-by-step” point-by-point approximation assembly strategy is proposed, which corrects the error through binocular vision guidance to improve the final assembly accuracy, which meets the requirements of high assembly accuracy and strong consistency of large-scale segmented optical components.

White-light scanning interferometry (WSI) is an important tool in the surface topography measurement. The range of white light interference fringes is very narrow, which makes the traditional method of finding fringes extremely timeconsuming and inefficient, affecting the efficiency and automation of the measurement. Aiming at these problems, a composite auto-focus method for on-machine WSI is proposed in this paper. Utilizing the feature of constant relative axial position of cutting tool and measuring system, the position near the interference fringes is quickly located. Then the mountain climbing strategy is adopted to roughly locate the focusing position with the wide spectral light source. Finally, the narrow spectral light source is used to accurately locate the position of zero optical-path difference by finding the coherent envelope peak. The experiments shows that the proposed auto-focus method is effective to find clear fringes in the on-machine interferometry measurement and can achieve a nanoscale accuracy within microns range.

With the development of optoelectronic technology, various infrared camouflage measures have been applied, causing changes in the infrared radiation characteristics of targets and backgrounds, affecting the detection ability of infrared imaging detection systems. Infrared polarization imaging technology is a new type of imaging technology developed rapidly abroad in the past decade. It uses the radiant intensity information and polarization information of the target simultaneously to improve the detection and recognition ability of the imaging system in complex background, and has a broader application prospect. This article is based on the polarization splitting ability of Wollaston prism, achieving the design of an infrared polarization dual-separation imaging optical system. The design adopts a single optical path, achieving simultaneous imaging of two polarization states of the target in the infrared band. It can obtain the two polarization information of the target in real-time, which is conducive to improving the system's ability to detect hidden or camouflaged targets.

The gravitational wave detection telescope system is located in a space environment and will be subject to radiation from the sun and Earth, as well as internal thermal power consumption. These factors will cause the gravitational wave detection telescope to be in a changing temperature environment. Due to the effects of structures such as light shields and insulation layers, the temperature environment of the optical system can be equivalent to a steady-state thermal equilibrium environment. Using an optical design software and finite element simulation software combined with an optical mechanical thermal integration design method, simulate the vacuum thermal equilibrium experimental states of the optical system at ambient temperatures of -15 °C, -5 °C, 5 °C, 15 °C, 22 °C, 35 °C, and 45 °C, and analyze the root mean square values of wavefront error, peak valley values of wavefront error, and reference light offset values for different states. At the same time, the vibration experiment of the optical system is simulated, linking mechanical vibration with optical performance analysis indicators, analyzing the PSD response function of mirror deformation RMS value under different working conditions, and the modes that have a significant impact on the composition image of the optical imaging lens.

Diffraction gratings have various optical properties such as dispersion, polarization, anti-reflection, and waveguiding, and are widely used in astronomical spectroscopy, holographic display, precision measurement, and other applications. The interference lithography method based on a phase mask uses the interference between diffracted orders of the phase mask to produce periodic patterns. Compared with conventional interference lithography, it has the characteristics of a simple and compact structure of the exposure system. The feature size of the transferable pattern is small, and currently, up to several hundred nanometers can be resolved and prepared; the grating parameters are repeatedly stable and suitable for producing a small number of gratings. First, this method is valuable in replicating diffraction gratings at low cost and high productivity. Moreover, combined with meta-structured phase masks, it can still have academic potential in preparing complex meta-structured patterns.

In the field of space optics, the compact freeform optical imaging system with small F number can realize the miniaturization and lightweight of the load, which is beneficial to enhance the ability of target recognition. In this paper, according to the vector aberration theory and the principle of Gaussian brackets, the error evaluation function is constructed by the primary wave aberration coefficients and focal length constraint of the system, and the dynamic weight is used to limit difference in the order of magnitude between various aberrations, which is conducive to rapid convergence in the process of solving the initial structural parameters. In order to achieve the compactness of the system, the circular layout is adopted. The unobstructed initial structure of the off-axis reflective system with conic surfaces is obtained through Particle Swarm Optimization (PSO) algorithm, and the off-axis three-mirror freeform optical system with a highly compact layout is obtained after optimization. In addition, considering the difficulty of freeform surfaces manufacturing, add the manufacturability constraint to the optimization process to control the degree of departure between the aperture edge of the freeform surfaces and the conic surfaces in real time. Compared with the optical system obtained without manufacturability constraints, the difficulty of manufacturing is effectively reduced.

Water exhibits excellent dielectric constant dispersion and high loss capacity in the microwave frequency range, making it an ideal material for broadband microwave absorbers. In this paper, a broadband water-cube-based metasurface microwave absorber (WMMA) is proposed, which is capable of regulating microwave absorption. The WMMA is comprised of the top layer of water-cube-based metasurface, the middle water absorption medium, and the bottom PMMA substrate. The impedance of the WMMA is determined by the design of the water-cube structure, resulting in a broadband and tunable microwave absorption coefficient. In the Ku band, the absorption intensity of the WMMA can cover the range from 71% to 99% by regulating h and p of the water-cube unit structure with a constant absorption coefficient over a wide frequency band. The broadband and tunable WMMA has the advantages of easy fabrication and low cost, rendering it highly promising for vast applications in the fields of electromagnetic shielding, stealth, and wireless communications.

Remote sensing satellite in low earth orbit is a kind of spacecraft developed to meet the needs of high-resolution imaging observation, rapid response to emergency earth observation and disaster image monitoring. In this paper, a finite element model of a remote sensing satellite camera with a diameter of 800mm thermal protection door (thermal door for short) was established. The topological optimization design technology is used to design the thermal door structures with high-reliability, high-strength and ultra-light. After optimization, the weight of thermal door is 4.5Kg. The finite element simulation analysis is carried out on the thermal door, and the analysis results show that the thermal door meets the harsh mechanical conditions of a satellite platform. The mechanical test of thermal door was carried out, and the test results match the simulation analysis results. After the mechanical test, the thermal boundary and vacuum conditions in orbit were simulated in the thermal vacuum experiment tank, and the thermal door’s opening and closing tests were carried out. The thermal door’s opening/closing time, opening/closing speed, structural stability and positioning accuracy meet the index requirements. This thermal door has been developed and delivered to the satellite. The research results of this paper have a certain reference value for the design of thermal door for remote sensing satellite cameras with low power consumption and high temperature control requirements..

The use of surface light sources enables accurate measurement of the morphology of high reflection surfaces. The fringe deflection method is a cost-effective and non-contact technology used to detect defects and measure the morphology of high-reflectivity surfaces. While this method can theoretically achieve global measurement of complex smooth surfaces, it faces practical challenges due to the significant difference in reflectivity across the surface. The high reflectivity area is easily affected by overexposure. Even if the exposure time and aperture can be adjusted, it can lead to significant quantization errors in the low reflectivity area, resulting in regional differences in measurement range errors. To address this issue and achieve simultaneous detection of multi-reflectivity objects without compromising accuracy, this paper proposes a novel detection method that adaptively adjusts the light source. By adjusting the exposure to obtain unsaturated captured images, absolute phase roughness measurement is achieved. Using the relationship between phase and projection fringes, spatial correspondence between the pixel coordinate system and the light source coordinate system is established, and adaptive adjustments are made to the projection light source. This approach enables adaptive intensity adjustments based on the reflectivity of the measured surface, facilitating high-precision measurement of complex surfaces. Overall, this adaptive light source technology enhances the fringe deflection method's accuracy and versatility, making it suitable for measuring complex surfaces with high reflectivity variations.

In lithography, the micromirror array (MMA) is utilized in the generation of customized source shapes optimized by source and mask optimization (SMO) technology. With irradiated laser ejecting from the surface of micromirror, the facula is positioned at the designated position. Through the progressive torsion of cantilevers, the electrostatic actuated micromirror realizes high-precision rotation corresponding to different driving voltages. Irradiated by 193nm UV laser, the heat sink accumulated on MMA leads to thermal expansion of structures. Thus, the voltage-angle (V-θ) curve serves deviation from the theoretical value, resulting in the distortion of illumination modes further. In order to estimate and eliminate the unfavorable effects on the rotation of MMA induced by heat sink, a biaxial electrostatic driven micromirror is initially designed and a multi-physical field model is established. Through equating the laser to a 2D surface source, in the thermal equilibrium state, the mirror surface temperature rises to 395.92K, with an introduced angular error of 3.313mrad when the driving voltage is 70V. The additional angle would exceed the design requirements of MMA and result in modes distortion. In order to eliminate the deformation of illumination mode in the pupil, a forced nitrogen cooling system is applied to suppress the accumulation of heat. Ultimately, the MMA without structural deformation could be adopted in the freeform pupil illumination modes generation in lithography.

With the increasing demand for navigation, obstacle avoidance and exploration, optical cameras are increasingly installed on unmanned underwater vehicles(UUVs). In order to meet the hydrodynamic performance requirements of UUVs, optical camera needs to be equipped inside optical fairing. However, traditional optical fairing can make optical cameras defocus and distortion, due to the difference in refractive index inside and outside the optical fairing. One of the common solutions is to replace the fairing with optical flat panel, but it will increase water resistance of UUV and affect the hydrodynamic performance. Another solution is to choose an optical camera that matches the additional focal length brought by the curvature of optical fairing, so that the optical fairing becomes a part of the camera lens. But the position of optical camera and optical fairing must be set strictly and precisely. Therefore, it is impossible to flexibly change camera, lens, optical fairing, and their positions. In this paper, a novel underwater low-resistance optical fairing is proposed. The shape of optical fairing is designed streamlined to reduce water resistance, and the water-filled structure eliminates the defocus and distortion effects caused by refractive index difference. Numerical simulations are performed to analyze the aberration and distortion caused by optical fairing. Comparison experiments of the proposed optical fairing and traditional optical fairing are performed. It is shown that the proposed fairing is simple in structure and flexible in implementation, which can enable clear imaging of optical cameras, and can be easily installed to achieve better hydrodynamic performance of UUVs.

Abrasive water jet processing technology is a processing method developed in recent decades using highenergy beams, which is suitable to removal and processing different materials, because its processing process has its own cooling effect and has incomparable advantages in other processing methods. Process studies involving multiple materials in the same area have not been reported. In this paper, the influence of abrasive water jet processing technology parameters on the removal rate of different materials in a small area is studied experimentally, and the removal rate of high-purity quartz glass, doped quartz glass and epoxy resin adhesive layer is tested by single factor and orthogonal test method. Experiments show that within a certain range of process parameters, jet pressure, nozzle diameter and nozzle height have obvious effects on the removal rate, while abrasive particle size have the lowest impact. Experiments are used to derive optimal process parameters for simultaneous removal of different materials.

The splicing sub mirrors of the Thirty Meter Telescope(TMT) primary mirror are off-axis aspheric shapes with large aspheric value. In order to reduce the time of stressed mirror annular polishing(SMAP), the mirror surface will be fine grinding using computer numerical control (CNC) processing device based on a six axis robotic arm before SMAP process, and the segment mirror will be lapping quickly benefit by high removal efficiency of fine grinding compared to polishing. In this article the principles of CNC processing, robotic arm motion controlling, and the experiment of fine grinding removal function are introduced. Finally, the segment mirror of TMT at the out edge is processed, and the fabrication convergence curve and final surface residual distribution are obtained. The optimized machining experience can further shorten the processing time and be used for early aspheric process of segments.

In the development of astronomy, high spatial resolution imaging technology plays a crucial role in astronomical observations. The introduction of the optical synthetic aperture concept satisfies the demand for high spatial resolution imaging, gradually becoming a novel direction in the advancement of optical interferometry. This study focuses on the investigation of Fizeau-type synthetic aperture imaging system and presents the design and performance analysis of a system based on requirements. The Fizeau-type synthetic aperture imaging system designed in this paper adopts reflective structure. The system operates in the visible light band (400nm~700nm), with a full field of view angle of 0.3°, an entrance pupil diameter of 300mm, and a focal length of 3598 mm. The sub-telescopes adopt the structure of coaxial two-mirror telescope system. The optical delay line adopts a parallel mirror structure. The beam combiner adopts an off-axis three-mirror structure. The performance of each sub-system and the whole system is analyzed. The results demonstrate that the synthetic aperture imaging system enhances the spatial resolution compared with the single sub-aperture system.

High-precision lens element polishing process can cause the mid-spatial frequency surface error and thus affect the image quality. In order to investigate the influence of the mid-spatial frequency errors on the performance of the photolithography illumination system, a partially coherent optical model is used. The mid-spatial frequency error generated by the processing is relatively complex and can be simplified to a random function convolved with a structured mid-spatial frequency error. This paper selects the mid-spatial frequency distribution from an actual processed aspheric, and adopts the penumbra width of the relay lens as an evaluation target. The analysis results shown that the surface closest to the pupil plane might be most impact factor.

The interworking between different networks can be effectively realized by implementing all-optical format conversion, and it can improve the flexibility, efficiency and expansibility of the communication system. The all-optical signal processing scheme is only carried out in the optical domain, and it does not require optical-electric-optical (O-E-O) conversion, which greatly improves the transmission rate and processing speed of the communication system. In this paper, an all-optical format conversion scheme from dual-polarization on-off keying (DP-OOK) to quadrature phase shift keying (QPSK) is proposed. The scheme is based on vector phase-sensitive amplification (PSA). Constellation and eye diagram of signals at each stage of system are obtained by simulation, and BER and EVM are calculated to show the performance of the system.

Right-angle conical mirror is widely used for wavefront conversion, which can construct a null interferometric optical path to achieve interferometric measurement of the cylindrical full-surface topography. However, the effect of the misalignment error on measurements is very significant, due to the difficulty in adjusting the position and attitude of the right-angle conical mirror and the measured cylindrical surface to the ideal state. The pure tilt misalignment errors will lead to parallel interference fringes. Based on this important finding, we propose a fast separation method of translation and tilt misalignment errors. First, adjust the relative translation of the right-angle conical mirror and the cylinder to be measured until all interference fringes are parallel. Then, perform measurement and remove the regular primary tilt from the result to separate the misalignment error effectively, so that the cylindrical full-surface topography is obtained. Under various misalignment errors, the extreme difference of all the PV values of the cylindrical surfaces measured by our method is less than 0.07λ. Experiments indicate that the proposed method can obtain essentially consistent measurements under different misalignment errors. Furthermore, the method is simple to operate and requires no data processing, laying the foundation for the practical application of cylindrical full-surface interferometry measurement.

With the development of space infrared focal plane detectors towards large-scale, multi spectral, and high integration directions, issues such as heat leakage, micro vibration, and structural thermal adaptation have become increasingly prominent, becoming bottlenecks that restrict the application of large-sized infrared focal plane detectors. By using a new Dewar with a string structure, the support problem of infrared focal plane components has been solved. Through the analysis and verification of force thermal coupling design, the new Dewar structure has effectively reduced heat leakage, Reduced the impact of micro vibrations and avoided detector stress caused by thermal adaptation, providing a solution for the application of high-performance large-sized infrared focal planes.