This PDF file contains the front matter associated with SPIE Proceedings Volume 13497, including the Title Page, Copyright information, Table of Contents, and Conference Committee information.

Aiming at the error problems in the computation of the fast Fourier transform (FFT) of the traditional Richards-Wolf focusing field in the xy-plane and xz-plane, this study proposes an improved FFT integration method, which aims to improve the computational accuracy through the integration boundary correction. The method is achieved by finely adjusting the integration boundary grid sampling point and integration area, specifically adjusting the integration boundary grid sampling point to the grid centre in Algorithm 1 and to the centre of the boundary polygon in Algorithm 2. In Algorithm 3, the boundary polygon is divided into triangles and the centres of the triangles are taken as the sampling points, and the product of the function value and the corresponding area at these points is calculated as the contribution to the FFT integration. Simulation results show that compared with the traditional FFT algorithm, the improved FFT algorithm significantly improves the computational accuracy while reducing the number of sampling points required, effectively reducing the computation time and improving the computational efficiency. This result fully confirms the effectiveness of the FFT algorithm based on the integral boundary correction in optimising the computational accuracy of the RichardsWolf focusing field FFT, which provides new powerful tools and methods for the research in the fields of holographic optical tweezers and the analysis of the optical field distribution near the focusing plane, and it is expected to push forward the technological advancement and the application development of these fields.

This paper employs the Zernike polynomials to optimize lens design, effectively overcoming the limitations of the traditional Simultaneous Multiple Surface (SMS) method in achieving uniform and symmetric light spot, thereby improving optical performance. This study constructs a non-imaging optical system by integrating the optimized lens with a detector array and applying the random forest algorithm to achieve orientation detection and prediction. The results show that the system’s azimuth and pitch field of view(FOV) are both ±6°, with a resolution 1°. The algorithm’s mean squared error (MSE) is 0.1593, and the determination coefficient (R²) is 0.9854, indicating good robustness. The system demonstrates broad application potential and market prospects in high-precision orientation detection.

A miniature hybrid FPI-FBG optical fiber sensor based was proposed to measure refractive index (RI) and temperature simultaneously. The integrated FPI-FBG composite fiber sensor is constructed by cascading an FP interference cavity at one end of the FBG, where the FPI is used to measure the liquid refractive index and the FBG to measure temperature and compensate for FPI. In this paper, Monte Carlo method is used to simulate the sputtering yield of three commonly used metal high reflection films (aluminum, silver and gold). Au film perform as the reflective mirror of the FPI due to its high sputtering yield and high stability. Owing to the different sensitivities, two-dimensional matrix method was constructed to calculating the refractive index (RI) and temperature synchronously. Experimental results show that the temperature and RI sensitivity of spectral dip wavelength for FPI are 0.338 nm/°C and 1669.5 nm/RIU, respectively. The FBG is insensitive to RI and temperature sensitivity of sensor is 9.8 pm/°C.

Inspired by the human visual system, the dual-lens optical system emulates the binocular stereoscopic vision. It captures two perspectives of the same scene from separate viewpoints, creating a sense of depth and a three-dimensional effect. Currently, research progress has been made in the design of dual-lens optical systems in terms of zooming and baseline variation, but there are still issues such as limited field of view and a narrow range of baseline variation. To overcome these limitations and extend the working distance of the system while ensuring image quality, this paper proposes a design method for an ultra-high definition dual-lens optical system with an extended rear stopping distance. This study first compares three traditional binocular stereoscopic imaging techniques (dual-lens dual-sensor, single-lens single-sensor, dual-lens single-sensor), analyzes the shortcomings of the current dual-lens optical system design, and proposes an improvement plan to increase the rear working distance of the system. Based on retaining some of the imaging advantages of the existing dual-lens single-sensor optical system, this study explores the possibility of achieving a long rear focal length and a compact volume by introducing an inverted telephoto structure. In the design process, the two optical paths are completely identical and mirror-symmetrical. This paper first designs a suitable initial structure for one of the optical paths and evaluates and optimizes the image quality. After the image quality meets the requirements, the dual-lens optical system is combined using multiple configurations in ZEMAX software to determine the final system structure. The focus of this study's design is on the inverted telephoto optical system, which adopts an asymmetric structure composed of positive and negative lens groups. The negative lens group reduces the field of view of the off-axis light to the positive group, achieving a wide-angle effect, while the positive lens group ensures that the image is formed on the designated working image plane, thus achieving a long working distance. This study is conducted on ZEMAX software, aiming to achieve an optical system with a rear working distance greater than 50mmand a focal length between 105-150mm, and analyzes the image quality, including the optical point spread function(PSF), modulation transfer function (MTF), spherical aberration, distortion, etc. The evaluation and analysis results of this study show that the image quality of the optical system is good, but further efforts are still needed to achieve good imaging over a wider field of view.

Large aperture mirrors play an important role in ground-based telescopes, space exploration and other fields, and have always been a research hotspot for opto-mechanical structure design. Large aperture lightweight mirrors are often limited by strict performance indexes. It is difficult to optimize the design with complex structures and many design parameters. In this paper, a mirror of Φ1.2m is taken as the research object. An 18-point support parametric model of the mirror is established based on geometrical constraint solving. The optimized design is carried out for the two types of support methods, namely passive support (equal support force) and active support (unequal support force), in order to achieve a better lightweight rate and adaptability. The results show that the optimized mirror has a mass less than 96 kg and a lightweight rate more than 82.7%. Under 1 g gravity, the RMS value of the mirror is less than 6 nm. And the deformation of the mirror can be further reduced by using the active support with unequal support force. This method can provide a reference for the optimized design of large aperture lightweight mirrors.

Curved LED screens are widely used in modern virtual filming and broadcasting technology, however, traditional planar imaging lenses are difficult to handle curved screens, resulting in image distortion and information loss. In order to solve this problem, this paper proposes an optical lens design method oriented to the principle of spherical screen imaging, which can project curved screen contents onto a planar sensor without distortion. The special lens designed using Zemax optical design software adapts to the curvature of the screen to achieve complete capture of the entire curved screen content. The lens consists of 8 pieces, F number is 5.6, focal length is 46.14mm, and the total length of the system is 121.65 mm. The experimental results show that the lens can achieve high-quality image capture on the curved LED screen, improve the imaging effect in the virtual filming and broadcasting, and expand the scope of application of the optical design, which provides a new technological possibility for the multimedia display and interactive entertainment in the future.

In order to achieve high signal-to-noise ratio for optical imaging, it is necessary to suppress stray light in space cameras. Sunlight is the main source of stray light, the smaller the solar suppression angle, the stronger the system's ability to suppress solar stray light, the more favorable it is to obtain images with better signal-to-noise ratio under strong backlight backgrounds. A off-axis three-reflection optical system was designed to meet the requirements of a large field of view and small solar suppression angle for space cameras. The camera’s field of view is rectangular, with the long side direction determining the width of the field of view. Based on the radiation characteristics of the target, a calculation method for the stray light suppression threshold is derived. Base on the optical form characteristics of off-axis three-reflection cameras, optical mechanical modeling is carried out, and optical simulation software is used to simulate stray light at real size. Through optical simulation and optimized structural design iteration, the stray light suppression scheme of the camera is finally determined. According to the requirement of minimum solar suppression angle, an asymmetric camera baffle is used to suppress stray light outside the view field, and some blocking boards are used to block stray light interference between the optical paths. In order to verify the effectiveness of stray light suppression measures, the optical path was simulated and analyzed using stray light simulation software, and the PST index met the design requirements. PST testing was conducted in the laboratory, and the test results combined with collimation data showed the the space camera meets the solar suppression angle of no more than 35 degree.

As a new generation of optical inertial navigation products, fiber optic gyroscopes (FOGs) have become a new trend in modern international inertial autonomous navigation equipment due to their technical advantages of high precision, full solid-state, and high reliability. In recent years, with the rapid development of China's fiber optic gyro industry, the application fields of FOGs have begun to actively expand from traditional areas to emerging fields such as smart oceans, smart cities, and intelligent navigation. In this process, traditional design and manufacturing methods cannot meet the new demands of emerging fields for FOG industries, which include high precision, miniaturization, flexible design, batch manufacturing, intelligent networking, diversified interfaces, full lifecycle services, and low-cost commercialization. This paper attempts to explore a new system for the design, manufacturing, and full lifecycle management of fiber optic gyros based on digital twin technology. It aims to closely integrate digital twin technology with key links, scenarios, and objects in the fiber optic gyro to enhance the level of intelligence and the efficiency and reliability of design, production, and verification. It is hoped that this work can provide a reference for the further development and application of digital twins in high-tech product industries, taking fiber optic gyros as an example.

In order to realize the measurement of the micro relative displacement of the optical components in the vibration environment, first of all, the vibration type of the electro-optical pod was analyzed. The relative micro displacement between the mirror and the frame in the vibration environment was simulated, especially the primary mirror component, which affects the imaging of the optical system by the reflector components. Then, a set of micro displacement measurement devices is designed to make it possible for measuring micro displacement in vibration environment with high precision. The relative displacement of the mirror and the frame in the primary component of an optical system is measured by the devices, the experimental measurement results are consistent with the simulation results. The high-precision measurement of the micro displacement of the optical components in the vibration environment is realized, which proves the effectiveness and correctness of the measurement devices and the method. On the basis of the accurate measurement of micro displacement, measurements to reduce the relative displacement between the mirror and the frame in the vibration environment are proposed, which provides an optimization direction for the improvement of the imaging quality of the optical system.

In the later stages of imaging optical system design, balancing the imaging performance across the full field-of-view is a major task, as the image performance over the entire image plane may vary significantly, and the performance at some field points may be very low and cannot achieve the design goal. A typical method for imaging performance balance is to adjust the optimization weights of sample field points in a repeating manner. However, as common optical design software cannot automatically adjust the weight values, the performance balance is done by the designers and the process may be very tedious and time-consuming. In this paper, we introduce an automated imaging performance balance method of complicated imaging optical systems. An out loop is introduced to automatically calculate and adjust the optimization weight of each field point based on its imaging performance after each iteration cycle. In addition, the weight is regulated by an extra factor which is calculated based on the performance change ratio of each field after the previous iteration step, in order to accelerate convergence. After a certain number of cycles, the imaging performance of the system is balanced. Human involvement is reduced to a minimum. The proposed method can be further integrated into commercial optical design software in the future.

This study investigates the impact of nitrogen doping concentration on the photocatalytic activity of TiO₂ catalysts. TiO₂ thin film samples with varying nitrogen doping levels were synthesized using radio frequency magnetron sputtering on fused quartz substrates. Comprehensive characterization techniques were utilized to analyze the crystal structure, morphology, nitrogen doping status, light absorption properties, and photocatalytic performance of these samples. Additionally, first-principles simulations were performed to examine the crystal structure, electronic structure, and density of states of TiO₂ across different nitrogen doping concentrations, aiming to clarify the underlying mechanisms affecting photocatalytic activity. The combined theoretical and experimental results reveal that nitrogen doping causes structural distortions in TiO₂, transitioning it from an indirect to a direct bandgap semiconductor and reducing the bandgap width. This alteration enhances the photocatalytic efficiency of TiO₂ thin films. Notably, the sample with 1.76% nitrogen doping demonstrated a photocatalytic efficiency of 58.95%, which is 2.08 times greater than that of undoped TiO₂ thin films.

In recent years, the superior optical properties of complex aspherical elements have provided optical designers with greater flexibility, leading to an explosive growth in demand across various applications. High-precision and reliable profile measurement technology is crucial for ensuring the quality of aspherical processing and the proper functioning of optical systems. To achieve high-precision, traceable measurements of complex aspherical mirror surfaces, a non-contact coordinate scanning measurement equipment based on an independent metrological loop is proposed. This equipment incorporates a dedicated metrology frame and utilizes multiple interferometric systems for real-time, accurate measurements of aspheric surfaces, ensuring the results are traceable to the SI definition of the meter. Specifically, the equipment features three co-referenced interferometric systems: two for real-time tracking of the optical probe's spatial position, and the third integrated within the miniature interferometric probe for measuring the surface shape of complex aspherical mirrors. The measurement principles of the interferometric systems are explained in detail. Each interferometric system utilizes a highly integrated waveplate-array quadrant photodetector to minimize optical components, mitigate processing and installation errors, significantly reduce system volume and mass, and decrease equipment load. Partial surfaces of standard spheres and aspherical mirrors were tested. The results showed a measurement error of less than 0.2 μm and the repeatability of 70 nm, achieving sub-micron accuracy.

Power-exponent-phase vortex (PEPV) beams have received particular attention for their unique capabilities in directional particle transport and collection. To the best of our knowledge, only the generation methods and properties of an individual PEPV beam have been studied and analyzed. In this paper, three types of grating phases for realizing power-exponent-phase vortex beam arrays are designed by taking advantage of the property that a Dammann grating can achieve a uniform energy distribution between laser far-field diffraction orders. Different types of gratings realize the generation of power-exponent-phase vortex beam arrays in the diffractive far-field, in which the topological charge distribution of each vortex has a different mathematical relationship with the diffraction order. In this paper, optical experiments are carried out by using a liquid crystal spatial light modulator loaded with grating phases. The experimental results are in agreement with the theory. The proposed method provides a new platform in optical communication, optical encryption and multiparticle manipulation.

In recent years, augmented reality (AR) optical technology has become a prominent focus in the field of optics. For near-eye display technology, achieving miniaturization and a large field of view (FOV) are critical objectives. And the compact design of the large FOV projection optical engine is essential for the miniaturization of the overall module. The system design, illumination uniformity analysis, and stray light evaluation were conducted. Finally, a prototype was fabricated.

The hybrid concentrating photovoltaic/thermal collector (CPVT) system utilizing beam splitting has tremendous potential for solar energy production. Spectral splitting allows for the decoupling of photovoltaic and photothermal processes, resulting in reduced temperature rise of the photovoltaic cells. This also ensures that the output heat energy of the photothermal module is not limited by the operating temperature of the PV cell, allowing for simultaneous generation of high-temperature thermal energy while maintaining high cell efficiency. While extensive research has been conducted to enhance the performance of photovoltaic cells under high temperatures and concentration ratios, few studies have investigated the impact of spectral beam splitting strategies on overall system performance. This work analyzed four computational methods for spectral splitting strategies (SSS) to evaluate their effectiveness using performance metrics. The conclusions drawn from this analysis are then used to identify the most suitable spectral splitting strategy for monocrystalline silicon photovoltaic cells. Furthermore, a novel CPVT system design based on micro-concentrator (MCT)system is proposed in this research. Using Zemax19 software for modeling, simulation, and theoretical calculations, a comprehensive evaluation of this system's performance was conducted while incorporating an optimal spectral splitting strategy. The analysis of the four computational methods indicates that integrating the energy efficiency method with the exergy efficiency method can achieve precise spectral splitting, ensuring theoretically optimal system performance. The simulation results reveal that due to suboptimal system design, both the energy efficiency and exergy efficiency of the system deviate significantly from the theoretical values, leaving considerable room for improvement.

To achieve better immersive effects and a comfortable wearing experience, current near-eye display systems are designed with large fields of view and large exit pupils as goals. However, optical aberrations such as field curvature and pupil swim are inevitable in these systems. There is currently a lack of comprehensive analysis methods and optimization techniques for field curvature and pupil swim in these systems. This paper employs forward ray tracing and simulates the human eye using ideal lenses to converge light onto the image plane. By calculating the positions of minimum spot size for different fields of view, the location of the virtual image plane is determined, and a three-dimensional model of the virtual image plane for the system is constructed. Through an iterative approach, it controls the positions of virtual image points for different fields of view to optimize the system's field curvature. Additionally, pupil swim causes image fluctuations when the eye moves, significantly affecting visual experience. This paper proposes a quantification method for pupil swim and analyzes its correlation with field curvature. Finally, by designing different near-eye display systems, the effectiveness of the analysis methods is demonstrated.

With the rapid development of space optical technology, the demand for the sensitivity of the optical system has increased, and the corresponding requirements for the suppression ability of stray light has become more critical. As an important part of the optical system to suppress stray light, the suppression effect of the baffle affects the final imaging quality of the entire optical system, and is currently developing in the direction of diversification, high efficiency, and light miniaturization. This paper elaborates the principles and application scenarios of various structural types of baffle, and analyses their applicability and limitations. According to the characteristics of various lens shield structures, they are divided into classical structure, reflective type, deployable type, honeycomb type and venetian blind type, and the characteristics and application fields of various structural forms of baffle are introduced. The research progress of light shields in recent years was introduced from the aspects of structural characteristics, suppression capacity, and application scenarios, and the advantages and disadvantages of various structures and the direction of improvement were discussed. Finally, the development direction of different structural forms of light shields is prospected.