This PDF file contains the front matter associated with SPIE Proceedings Volume 13282, including the Title Page, Copyright information, Table of Contents, and Conference Committee information.

The InGaAs infrared detector, as the core component of photoelectric conversion in the Synchronization Monitoring Atmospheric Corrector (SMAC), is responsible for measuring short-wave infrared spectral and polarization information. Among them, the service life of the thermoelectric cooler (TEC) poses a bottleneck for the overall lifespan of the infrared detector, and its reliability directly affects the normal operation of the detector. A thorough analysis is conducted for the working mechanism of the infrared detector utilized by SMAC and the failure mechanism of the TEC, and the lifetime characteristic of the product is comprehensively evaluated and analyzed through lifespan testing. To minimize time costs, an innovative accelerated lifetime test method is proposed, which utilizes temperature change rate as the accelerated stress. A lifetime test system is developed. Meanwhile, the dark current, relative spectral response, and cooling current of the infrared detector have been measured before and after the lifetime test based on the segmented uniform illumination light source. The experimental results reveal that after a cumulative lifetime test of approximately 120 days, the infrared detector underwent approximately 170,000 temperature cycles. The maximum delta value in the relative spectral responsivity of the infrared detector pre and post the life test is -1.86%, and the maximum increase in the TEC refrigeration drive current is 8.6%. The service life and performance changes of the detector could satisfy the requirements of space payloads. Moreover, the lifetime test system significantly improves test efficiency and exhibits excellent stability and scalability, fully capable of meeting the needs of lifetime tests under different temperature stress levels.

Comparing two existing polymer fiber optic faceplates preparation techniques at home and abroad, this study innovatively proposes a new strategy for the preparation of polymer fiber optic faceplates based on a drawing and hot pressing method. Using this drawing and hot pressing method, we successfully prepared advanced polymer fiber optic faceplates with high consistency and up to 94% light transmittance. Experimental results show that the faceplates prepared by this process have excellent performance in terms of image transmission quality and resolution, which fully meet the needs of diverse practical applications. Based on the research results, we firmly believe that the continuous advancement of polymer fiber optic faceplates technology will bring disruptive changes in the field of optical sensing and display, as well as injecting new vitality and inspiration into future technological innovations. This technological breakthrough will not only promote the rapid development of related industries, but also provide strong support for the innovation of global optical technology.

To enhance the accuracy of existing algorithms in the task of retinal vessel image segmentation, this paper proposes the incorporation of two modified convolutional blocks, in lieu of traditional ones, within the framework of the U-Net neural network, aiming to strengthen the extraction of detailed features. Firstly, a convolutional block equipped with local channel attention is devised for feature extraction in the shallow layers of the network. Secondly, a convolutional block incorporating global channel attention is introduced for feature extraction in the deeper layers. Lastly, skip connections are employed to feed the features extracted from the shallow layers into the deeper layers. Experimental results demonstrate that the proposed retinal vessel segmentation algorithm achieves a Dice coefficient of 88.21% and a sensitivity of 87.16%, marking improvements of 2.25% and 1.64% respectively over the original U-Net network.

The pixels will be remapped when a pattern is projected by a Digital Light Processing (DLP) projector with diamondshaped pixels. In order to achieve high-quality 3D shape measurement in fringe projection profilometry (FPP) system consists of this type of projector, the influence of different pixel remapping method on measurement accuracy was studied. The sinusoidal fringes with diamond-shaped zigzag, column interleaved diamond straight-line and rectangular straight-line pixel arrangements were designed for experiments according to the actual pixel remapping rule. The phase measurement error of 12 projector-camera pixel size ratios (from 0.5 to 85) and under different defocusing degree were investigated. The phase of the fringe was calculated using the standard four-step phase-shifting algorithm. The experimental results show that when the projector-camera pixel size ratio (PPSR) is high (e.g., 5), the phase measurement error of diamond-shaped zigzag sinusoidal fringe is significantly larger than the other two, and the phase measurement error of column interleaved diamond straight-line sinusoidal fringe is larger than that of rectangular straight-line sinusoidal fringe. It is concluded that the highest 3D measurement accuracy can be achieved by projecting column interleaved diamond straight-line sinusoidal fringe based on the structure of FPP system and the phase-height mapping relationship. These research results provide important reference value for the design of high-resolution FPP systems.

The continuous development of two-dimensional materials has put forward a higher demand for instrument detection performance, in which Raman polarization is an important reference to judge the optical properties of materials, but the existing Raman polarization detection cannot detect the super-resolution spatial distribution information. In this paper, a wide-field Raman polarized structured illuminated super resolution microscope is proposed. Based on SIM model and tunable filter, wide-field Raman signal could be acquired. According to the characteristics of low signal-to-noise ratio of Raman scatting, HiFi SIM and pSIM are combined to reduce the reconstruction artifacts and realize the demodulation of Raman polarization super-resolution images effectively and correctly. We successfully realized the G-band imaging of 100𝑛𝑛𝑛𝑛 single-walled carbon nanotubes based on this system and algorithm, which verified the correctness of the polarization calculation of the system.

Refractive index mismatch between different tissues will cause light scattering and thus induce light attenuation. The imaging depth of Optical Coherence Tomography (OCT) and Photoacoustic Microscopy (PAM) are limited by the light attenuation, especially in shorter wavelength regions (OCT at 800 nm and PAM at 532 nm). Over the past few decades, Optical Clearing Agents (OCAs) have been extensively explored and widely used to achieve deeper optical penetration in transparent tissues. In this study, we used a 40% glucose solution as an OCA to enhance tissue transparency and reduce light attenuation during deep tissue imaging. The transparency effects on the ex vivo anterior segment of rabbit eyes were verified using OCT. For in vivo treatment, we applied a 40% glucose solution topically to the anterior segment of rabbit eyes and subsequently performed imaging using dual-modal PAM and OCT system. The results showed that the glucose solution altered the tissue refractive index, enhancing both signal intensity and imaging depth. Therefore, this study may provide a potential method for investigating the theory of ocular accommodation by offering deeper cross-sectional structural images and detailed vascular information of the anterior segment, while also expanding the imaging applications of OCT and PAM.

Structured illumination microscopy is more suitable for super-resolution imaging of live cells and holds promising prospects in bioscience thanks to its fast imaging speed and low photodamage. However, in order to achieve fast, real-time and long-term imaging of live cells, further enhancements in imaging speed and reductions in photodamage are necessary. In this work, we optimize from both algorithm and hardware aspects. First, a Fourier ptychographic SIM algorithm (FP-SIM) using only three patterns is proposed to reduce the number of frames required for reconstruction. Second, we use CUDA to design appropriate parallel methods on hardware to accelerate the algorithm. We demonstrate that GPU improves the speed by nearly 200-fold in the most time-consuming iteration part of the algorithm. At 512×512 pixels, real-time super-resolution microscopy imaging at approximately 16Hz can be achieved. Faster imaging speed and less photodamage enable our method to provide a promising tool for life science research and biomedical measurement.

Terahertz (THz) technology, due to its non-ionizing nature and high sensitivity to the water content in substances, demonstrates significant potential in areas such as tumor analysis, skin tissue examination, burn assessment, and the analysis of traditional Chinese medicine components. This study investigates a novel method for detecting organic materials using THz technology. The experiment involved both normal and skin barrier-damaged mice. Samples were prepared using different methods, including direct slicing, 60°C water bath skin scraping, and enzymatic treatment, and were observed using THz spectral imaging. The study found that mice with damaged skin barriers exhibited significant differences in THz imaging and THz time-domain spectroscopy, reflecting changes in water distribution and tissue structure within the skin. This method not only non-invasively and efficiently reflects differences in skin barrier function but also verifies the accuracy of imaging results through THz time-domain spectroscopy. It shows promise for early diagnosis and monitoring of skin diseases, advancing the fields of dermatology and biomedicine.

For 3D imaging based on fringe projection, Temporal Phase Unwrapping (TPU), which can robust absolute phase recovery, is of importance for measuring complex scenes with surface discontinuities. In this paper, we present a fast 3D imaging using reference-phase-based number-theoretical temporal phase unwrapping. By introducing the reference phases into the traditional number-theoretical TPU, the proposed method with the aid of the optimal bi-frequency scheme has the ability to efficiently and accurately eliminate the phase ambiguities of high-frequency fringes, while theoretically circumventing the limitations of the measurement range. Experimental results demonstrate that the proposed method enhanced the efficiency and accuracy of absolute phase measurement, achieving fast, wide-field-of-view, and long-distance 3D imaging.

Terahertz-based non-destructive testing utilizes a point-scanning imaging process to capture comprehensive regional information through high-density grid sampling. Accurate estimation of characteristic parameters such as refractive index, dielectric constant, and absorption coefficient requires addressing a multi-parameter numerical problem with micrometer-scale precision in sample thickness. Given the demands of high frame rate imaging, purely CPU-based computing frameworks are insufficient for the required rapid processing. Consequently, this paper introduces a GPUaccelerated terahertz spectroscopic characteristic parameter measurement algorithm using CUDA technology. The system enhances performance by streamlining data transfers between devices and performing batch Fourier transformations on multiple short one-dimensional sequences. It also leverages shared memory to efficiently execute distributed detection of signal peaks and spectral matching. Furthermore, a fitness function based on the distribution of local extrema across multiple consecutive data buckets is proposed, facilitating rapid comparison and optimization of results. Experimentally, the system was tested on both simulated data of single and double-layer media and real data from the MenloSystems terahertz time-domain spectrometer. Experimental results indicate that NVIDIA GeForce 30 series GPU acceleration increases processing speed by 5 to 8 times relative to traditional CPU methods. Additionally, by exploring and sampling in a more refined parameter space while maintaining a computation speed of 100ms per measurement point, the accuracy of refractive index determination improved by 80%. These achievements not only underscore the potential of GPU acceleration in enhancing terahertz spectroscopy performance but also provide substantial support for the continued advancement of related technologies.

A novel holographic recording method is proposed in this paper. When preserving the unchanged holographic reconstructed image, we introduce a method to modulate the reconstructed correlation spectrum into a preset structure, which implies that both the reconstructed image and correlation spectrum serve as information carriers. Building upon Fourier holographic recording principles, we elucidate the underlying mechanism and investigate the influence of sub-image shape on the correlation spectrum of holographic reconstructed light field. Futhermore, a new holographic algorithm of sample and recording CSI-OSIA-HR permits that the sub-image obtained intelligently by the random preset center-symmetric correlation spectrum. To validate the algorithm, we conducted holographic experiments using center-symmetric “Chun”, “Taiji Yin-Yang Fish”, and “Eight awn star” as various preset images. When the Fourier holographic record of different objects is carried out, and the simulation calculation shows the correlation spectra of different objects and different presets, the reconstructed images are consistent with the holographic record presets in the reconstructed light field obtained by the algorithm, and the correlation spectral structure is also perfectly in line with the preset patterns. This novel holographic recording scheme simultaneously encodes preset image information within both the hologram and its correlation spectrum, offering potential applications in artistic holography and holographic encryption.

Fluorescence imaging is one of the basic research of biological microscope imaging, and improving the imaging depth of biological microscopes has always been a research hotspot . One of the factors affecting the depth is that the excitation light will be absorbed and scattered by the tissue and cannot be focused on the target fluorescent area. Therefore, this study uses an adaptive optics scheme to correct the wavefront phase of the excitation light, and uses the intensity of fluorescence as a quantitative parameter. The results show that the research scheme in this paper has a good effect on improving the quality of deep imaging.

X-ray induced Acoustic Computed Tomography (XACT) is a new imaging method based on thermoelastic effect, which has the advantages of low x-ray radiation dose and high resolution. In this paper, clinical linear array was used in XACT for osteoporosis assessment. In order to optimize the XACT process, clinical linear array with different elements were used in XACT simulation imaging to select the optimal element number for best image quality. Furthermore, XACT simulation image of osteoporosis was demonstrated compared with CT image, which demonstrate that this technique has future potential clinical applications for assessment in physiologic osteoporosis.

With the simultaneous development of jujube industry and intelligent agriculture, there is an increasing demand for collecting pre-evaluation of jujube quality using high technology. This paper proposes a non-contact multi-angle red jujube quality quantitative detection device based on light field modulation. This device realizes non-contact theoretical telemetry by superimposing multiple lenses in front of the spectrometer and uses the spatial light modulator SLM to change the size of the light field spot in order to change the detection range of the light field, and to explore the precision of red date quality detection under different light spots at multiple angles. After experimental verification, the moisture content of jujube tested by the detection device, the correlation coefficient of jujube correction set is 0.743, the correlation coefficient of prediction set is 0.694, and the average absolute error is 1.190%. The overall can make a preliminary judgment on the quality of jujube.

Based on the traditional iterative algorithm, phase-only element was used to generate vortex beams with two Orbital Angular Momentum (OAM) modes in different energy ratios. The use of pure phase modulation results in the presence of undesired OAM modes in the vortex beams, which follow a pattern. Additionally, the number of initial input parameters in the iterative algorithm affects the energy ratio between the two OAM modes. By adjusting the number of initial input parameters, a more desirable relative power distribution can be achieved.

Spatial Heterodyne Spectrometer (SHS) is a novel Fourier transform spectroscopy technique characterized by high spectral resolution, high light throughput, and high stability. It is widely used in remote sensing and astronomical observations. In this paper, we designed a dual-grating spatial heterodyne spectrometer, employing a dual-beam interference system and an improved optical system to enhance spectral resolution and detection sensitivity. In simulation experiments, the optical performance of the spectrometer was analyzed through numerical simulations. The results indicate that this design can achieve a theoretical spectral resolution of 1.23 cm^-1 over a broad spectral range of [16043.6, 20755.6] cm⁻¹ ([481.8,623.3]nm). We constructed an experimental prototype of the spectrometer and conducted a series of tests in a laboratory setting, which verified the reliability and accuracy of the simulation studies.

In this paper, we utilize a terahertz (THz) reflection detection structure to examine multilayer heterogeneous samples and propose an improved non-destructive testing algorithm. Firstly, the Rouard equation is introduced to establish a THz wave reflection model. To enhance the model's accuracy, the Debye model is employed to calculate the dielectric constant, determining the refractive index of the samples. The model parameters are solved using genetic algorithms and the African vulture optimization algorithm. Experiments were conducted using a six-axis robotic arm and a THz spectrometer to detect non-metallic composite material samples. The results demonstrate that the proposed algorithm can accurately detect the samples, with a thickness measurement precision of 1 micrometer and an error margin within 4%. This study proposes a more reliable non-destructive testing algorithm based on terahertz time-domain spectroscopy technology, advancing the application of terahertz technology in the power industry and industrial production.

The patch shape of microstrip patch antenna is an important factor affecting the performance of the antenna, in order to make the microwave antenna miniaturization, high gain performance requirements, respectively, k-band operating frequency at 24GHz rectangular and circular coaxial fed microstrip antenna simulation, compare the performance and size of the circular and rectangular microstrip antenna, the dielectric substrate using Rogers 4350, the dielectric constant of 3.66, the thickness of substrate is 0.5mm. The simulation results show that the circular coaxial fed microstrip antenna operating at 24GHz is superior to the rectangular microstrip antenna in terms of size and performance, and this structure can be used in the development of small microwave sensors for the transmission and reception of microwave signals.

Structured Illumination Microscopy (SIM) has become one of the most important fluorescence super-resolution technologies in living cell research due to its advantages of full-field imaging and low light damage. However, SIM is a multiframe imaging technique that requires complex parameter estimation, which severely limits imaging quality and speed. To address these issues, this paper proposes an ensemble learning based single-frame composite structured illumination microscopy (E-SIM). This method obtains the full-field modulation information through only one frame composite structured illumination and combines the advantages of Convolutional Neural Networks (CNNs) and Transformer to reconstruct high-quality super-resolution images from a single-frame input image, which significantly reduces phototoxicity and photobleaching. Experimental results show that E-SIM can successfully reconstruct high-resolution images in various biological samples.

Periodic arrays of nanoscale structures on wafer surfaces can be fabricated using micro- and nano-fabrication processes. By changing the morphology and arrangement of array structures, precise control of light can be achieved, enabling the functionality of various optical devices. The paper simulates the nanoscale array structures on the wafer surface using Finite-Difference Time-Domain (FDTD) method and conducts microscopic imaging. After wavelength optimization, it was found that for the single-layer SiO₂ array structure on the wafer surface, with shorter illumination wavelengths and larger objective numerical apertures, the characteristic information of the SiO₂ structure becomes more prominent in the microscopic imaging. However, for the multi-layer SiO₂-Si₃N₄-SiO₂ array structure on the wafer surface, the illumination source no longer follows the principle that shorter wavelengths and larger numerical apertures result in better imaging quality. Instead, the optimal imaging quality is achieved with illumination wavelengths in the range of 230nm-260nm and a numerical aperture of 0.55 for the objective lens. Therefore, in practical testing, appropriate illumination wavelengths and numerical apertures for the objective lens should be selected to achieve the best imaging quality.

Ultraviolet (UV) Raman spectroscopy, compared to visible Raman spectroscopy, offers advantages of higher Raman scattering intensity and no fluorescence interference. This paper designs a Czerny-Turner type UV grating spectrometer based on freeform surfaces. By analyzing the aberration principles of the Czerny-Turner spectrometer and combining the parameters of each component, an initial structure was established. For significant astigmatism in the system, optimization using freeform surfaces in the form of XY polynomials was performed, resulting in a UV grating spectrometer with a wavelength range of 250-310 nm and an object-side numerical aperture of 0.125 with a slit width of 20 μm. The spectral resolution simulation based on the line spread function indicated that the spectral resolution across the entire wavelength range is better than 0.085 nm. The modulation transfer function (MTF) results show that the MTF in both sagittal and tangential directions is close to the diffraction limit, indicating good image quality and the elimination of astigmatism while ensuring spectral resolution and improving energy concentration.

The Coded Ptychography (CP) achieves robust phase reconstruction by combining coded layers and overlapping scanning, however the requirement for a high scan overlap rate leads to a conflict between measurement precision and efficiency. This research suggests Coded Aperture Ptychography (CAP) as a solution to this issue. The amplitude modulation function of the spatial light modulator is employed to encode the detecting light's aperture, guaranteeing a consistent corresponding coding layer for every scan and offering ample phase diversity to enable high-precision phase recovery. In addition, to reduce the measurement complexity, a phase retrieve algorithm was proposed to reconstruct the object, incident beam, and coding layer all at once, and the absorption and amplitude constraints of the coding layer aperture were introduced to improve measurement efficiency and accuracy. We demonstrate in simulated studies that when the overlap rate is decreased to 0.2, the measurement accuracy of the CAP technique can be comparable to that of the CP method when the overlap rate is 0.8, and the number of algorithm iterations is lowered to a seventh.

With the emergence of Neural Radiance Fields (NeRF), arbitrary view synthesis has made significant progress. However, most existing methods perform well only with low-resolution inputs, and they usually suffer from blurred synthesized views and high memory footprints as the input resolution increases, especially for dynamic scenes. To this end, this paper proposes a novel and effective framework that achieves a super-resolution dynamic NeRF for high-resolution arbitrary view rendering. Specifically, we first use a dynamic NeRF with HexPlane representation to learn a low-resolution neural model of dynamic scenes, which can synthesize low-resolution images from arbitrary views and times. Then, a spatiotemporal consistent super-resolution module is designed to reconstruct high-resolution synthesized views, which adopts a staged training strategy to enable our model with the ability to perceive geometric local context and detail processing. Experimental results demonstrate that our method can effectively generate high-quality super-resolution images from arbitrary viewpoints and times when dealing with dynamic scenes.

This conference paper presents an initial investigation on implementing an AO system on small satellites in VLEO, focusing on the complex orbital environmental factors that affect the satellite’s structure. Particular attention is given to the uncertainties of these excitation factors, which can cause unexpected motions and attitude changes. A novel control strategy is proposed, incorporating additional sensors into the system, with several self-sensing architectures implemented. The control scheme outlined in this study is intended for potential iterations of the technology in future applications.

Coherent diffraction imaging(CDI) is a lensless imaging technology that can achieve an accuracy higher than the resolution limit. Improving the accuracy of simulation results for diffraction is of great significance for the development of coherent diffraction imaging technology. In this work, a method to calculate the intensity distribution of diffraction light for certain given objects will be illustrated, which is not based on the Fourier transform algorithm. This method can achieve simulation results closer to actual experiment results, while it will be more time-consuming. Five different objects are selected to calculate intensity distribution of diffraction light on different record planes, with various ranges of pointing stability.500 simulation results are achieved in total. The influence from pointing stability on simulation results of intensity distribution of diffraction light is analysed and illustrated.

The rapidly developing non-line-of-sight (NLOS) imaging technology in recent years is capable of intelligent visual perception of concealed targets, holding broad application prospects in security, emergency rescue, autonomous driving, etc.. Compared to active methods, passive NLOS imaging is promising to in real-world scenarios due to its low cost. This paper uses the long-wave infrared (LWIR) to detect multiple hidden targets. In contrast to the visible band, LWIR exhibits a higher proportion of specular reflection scattering on common relay surface but cannot represent details such as texture. Furthermore, passive NLOS imaging reconstruction is an ill-posed problem, leading to sparse and blurred features, which poses significant challenges for multi-target detection tasks. To address this, the paper proposes a deep learning method for collaborative multi-task image reconstruction and detection. The detection loss is backpropagated and fused with the imaging enhancement loss to guide the NLOS target reconstruction process towards high-quality detection results. Comparative experiments are conducted in multi-person target scenarios between the latest target detection methods and our method. The results indicate that our proposed method exhibits the best performance in terms of detection accuracy, recall rate, and the F1-score. Additionally, this paper demonstrates the generalization of the proposed method at different distances ranging from 10 to 20 meters. The related results provide data and methodological support for the advancement of NLOS imaging towards practical applications.