To achieve the recognition and 3D reconstruction of space target components in complex, low-texture environments for space situational awareness tasks, this paper proposes an end-to-end intelligent perception framework for space targets based on deep learning. This framework enables intelligent recognition and high-precision 3D reconstruction of key space target components. The current space target sensing task is facing great challenges, the surface of on-orbit targets are mostly low-texture metal materials, traditional feature matching methods are ineffective, and the geometrical structure of the components is complex and there is occlusion, so it is necessary to take into account the global semantics and local accuracy. First, based on the lightweight YOLOv11s network, an attention mechanism is introduced to focus features, achieving precise localization and recognition of space targets and their key components while ensuring real-time performance. This facilitates the extraction of target regions for accurate 3D reconstruction. Subsequently, a novel 3D reconstruction algorithm named Sat-TransMVSNet, specifically designed for low-texture space targets, is proposed. This algorithm employs a multi-scale feature enhancement network for feature extraction and utilizes a novel cost volume regularization method to strengthen geometric constraints at space target edges. It incorporates a background-suppression and foreground-enhancement module, combined with a dynamic depth sampling strategy, to accurately reconstruct space targets. Finally, the overall framework is tested using a self-built multi-angle space target dataset comprising various types. Experimental results indicate that the component recognition algorithm achieves an mAP50 of 0.95, and the comprehensive 3D reconstruction error is 0.2886 mm. This demonstrates the framework’s capability to meet the requirements for high-precision 3D reconstruction of space targets and intelligent recognition of key components.

In order to investigate the imaging function of metasurface based on geometric phase theory, this article deduces the imaging formulation of arbitrary curve with the theory of geometric phase imaging on metalens, and its feasibility and correctness is verified by scalar diffraction theory. The imaging formulation is further applied in polarization detection of the incident beam. The results show that phase manipulation of metasurface based on geometric phase can achieve the functions of arbitrary curve imaging and polarization detection of the incident beam, which is of great significance in the field of holographic imaging, optical communication and quantum science.

Laser absorption spectroscopy (LAS) has been widely applied in atmospheric monitoring, industrial production, medical diagnostics, and other fields due to its high sensitivity, rapid response, and real-time online detection capabilities. However, spectral overlap interference remains a major challenge in LAS. In this study, a multispectral analysis approach based on cavity ring-down spectroscopy (CRDS) is proposed. A CRDS gas detection system was developed using a custom-designed cage-type Fabry-Pérot cavity, and seven acetylene (C₂H₂) absorption lines in the range of 6452 cm⁻¹ to 6453 cm⁻¹ were selected for investigation. Experimental results demonstrate that the system can accurately measure and fit the C₂H₂ multispectral lines, achieving a minimum detectable limit of 3.517×10⁻⁸ cm⁻¹, corresponding to a minimum detectable volume fraction of 4.37 ×10⁻⁶ for C₂H₂ gas. Additionally, the pressure in the cavity was precisely measured with a calibrated high-precision vacuum gauge, and the pressure-broadening effect in the absorption spectroscopy was used to calculate the pressure-broadening coefficients for three absorption lines, with relative deviation below 0.04. This study provides a novel method for multispectral analysis in LAS, improving measurement accuracy and broadening its applicability.

This study investigates the reduction in polarization measurement accuracy caused by varying incident angles in a liquid crystal variable retarder (LCVR). The phase delay characteristics of the LCVR were examined, with particular emphasis on the influence of different two-dimensional incident angles on phase delay behavior. Building upon the calibration of phase delay under normal incidence, a phase delay calibration model was developed to account for variations in incident angle and driving voltage. A mathematical relationship was established between phase delay and the azimuth angle (α) and pitch angle (β). Experimental validation was conducted under three conditions: α = 20°, β = 0°; α = 0°, β = 20°; and an arbitrary angle where α = 5°, β = 15°. The results demonstrated that the maximum average deviation between theoretical predictions and experimental measurements did not exceed 0.059 rad. The proposed calibration method proved to be both accurate and practical. This approach offers robust support for LCVR parameter calibration and performance optimization in optical systems, particularly in polarization imaging applications.

To address the challenges of complex metallic film coating processes and low integration in single-parameter detection for existing photonic crystal fiber surface plasmon resonance (PCF-SPR) sensors, a dual-parameter sensor based on gold nanowire-integrated bias-core PCF-SPR is proposed. Unlike conventional in-hole coatings or metallic film structures, the gold nanowires are directly attached to the fiber cladding via chemical vapor deposition (CVD), eliminating uneven coating issues and significantly simplifying fabrication. By optimizing the asymmetric bias-core fiber structure and leveraging the strong localized field enhancement of gold nanowires, the sensor achieves high-sensitivity synchronous detection of temperature (25−60 °C) and refractive index (1.31−1.40) in dual-polarization modes. The simulation results demonstrate that the x-polarization mode can achieve 1.31−1.40 refractive index detection with maximum wavelength sensitivity and amplitude sensitivity of 14800 nm/RIU and −1724.25 RIU⁻¹, and maximum refractive index resolution of 6.75×10⁻⁶ RIU. The y-polarization mode achieves refractive index detection range to 1.34−1.40, and the maximum wavelength sensitivity and amplitude sensitivity are 28400 nm/RIU and -1298.93 RIU⁻¹, and the maximum refractive index resolution is 3.52×10⁻⁶ RIU. For temperature sensing, the sensor exhibits a wavelength sensitivity of 7.8 nm/°C and a high resolution of 1.38×10⁻⁶ °C over the range of 25−60 °C. This design synergizes gold nanowires and the bias-core architecture to simplify fabrication while enabling multi-parameter detection. The proposed sensor offers new insights for integrated applications in biochemical monitoring, environmental sensing, and related fields.

AlGaN-based deep-ultraviolet (DUV) laser diodes (LDs) face performance challenges due to electron leakage and poor hole injection, often worsened by polarization effects from conventional electron blocking layers (EBLs). To overcome these limitations, we propose an EBL-free DUV LD design incorporating a 1-nm undoped Al_0.8Ga_0.2N thin strip layer after the last quantum barrier. Using PICS3D simulations, we evaluate the optical and electrical characteristics. Results show a significant increase in effective electron barrier height (from 158.2 meV to 420.7 meV) and a reduction in hole barrier height (from 149.2 meV to 62.8 meV), which enhance carrier injection and reduce leakage. The optimized structure (LD3) achieves a 14% increase in output power, improved slope efficiency (1.85 W/A), and lower threshold current. This design also reduces the quantum confined Stark effect and forms dual hole accumulation regions, improving recombination efficiency. Our findings present a promising approach for high-performance, EBL-free DUV LDs suitable for high-power applications.

Standard bacterial suspensions play a crucial role in microbiological diagnosis. Traditional preparation methods, which rely heavily on manual operations, face challenges such as poor reproducibility, low efficiency, and biosafety concerns. In this study, we propose a high-precision automated colony extraction and separation system that combines large-field imaging and artificial intelligence (AI) to facilitate intelligent screening and localization of colonies. Firstly, a large-field imaging system was developed to capture high-resolution images of 90 mm Petri dishes, achieving a physical resolution of 13.2 μm and an imaging speed of 13 frames per second. Subsequently, AI technology was employed for the automatic recognition and localization of colonies, enabling the selection of target colonies with diameters ranging from 1.9 to 2.3 mm. Next, a three-axis motion control platform was designed, accompanied by a path planning algorithm for the efficient extraction of colonies. An electronic pipette was employed for accurate colony collection. Additionally, a bacterial suspension concentration measurement module was developed, incorporating a 650 nm laser diode as the light source, achieving a measurement accuracy of 0.01 McFarland concentration (MCF). Finally, the system’s performance was validated through the preparation of an E. coli suspension. After 17 hours of cultivation, E. coli was extracted four times, achieving the target concentration set by the system. This work is expected to enable rapid and accurate microbial sample preparation, significantly reducing detection cycles and alleviating the workload of healthcare personnel.

Filters, as a key component in the photoelectric detection system, can simplify the optical system and improve detection efficiency. Based on the usage requirements, a visible/near-infrared filter film with up to 5 wavebands needs to be designed and prepared, while simultaneously satisfying high reflection in 2 wavebands and high transmittance in 3 wavebands. Therefore, we have conducted a systematic study on the film design, thin film preparation process, and control accuracy of film layer thickness. In this work, the short-wave pass film system is superimposed with the long-wave pass film system, and the number of cycles and matching coefficient of the film system are tuned to meet the requirements of cut-off band. Additionally, Smith method was used to match bandpass film system to optimize the transmission band and complete the visible/near infrared multiband laser filter film design. In the preparation process, combined with the sensitivity of the film layer, inverse analysis is used to invert the film layer monitored by each optical monitoring chip. The optical control scheme with weak optical signal in the monitoring process is simulated and corrected, and the monitoring wavelength with stronger optical signal is matched, resulting in an improvement of the control accuracy for the film thickness and the transmittance in the specified wavelength range. Ultimately, the actual physical thickness is 9.66 μm, and the error with the theoretical design thickness is less than 0.4%, and the transmittance of the specified 3 wavebands exceeds 99%. The average transmittance of the cut-off bands at the 455−500 nm and 910−1000 nm is 0.45% and 0.16%, respectively.

The dual-wavelength image plane digital holography is employed to achieve the long-distance topography measurements, which is expected for the Examination and Analysis System Technology (EAST) in divertor surface monitoring. The same-path design for the illumination and imaging beams is suitable for the upper diagnosis channel of the tokamak device. By selecting two wavelengths with a gap of 1.02 nm, the measurement range of system is extended to 276.87 µm, allowing for 138.44 µm gradient measurements. Experimental results demonstrate that the measurement error of the system for a step with a nominal high of 80 μm is 7.00%, with a minimum detectable height variation of 10 μm. Furthermore, confirm the long-distance measurement capability of the system, and off-line measurements were conducted on a dismantled divertor from a tokamak device. Which proves the system can be applied to the topography measurements of the divertor.

In order to minimize misalignment angle errors in laser-guided seekers, we have optimized the quality of energy signals through advanced optical design techniques. The initial design parameters were derived by integrating aberration theory with sophisticated optical design software. We then employed an iterative design process for the optical system, focusing on both the optimization of the optical structure and the balance of aberrations. To enhance angular measurement precision, we improved the symmetry of the light spot by carefully controlling the image-side telecentric condition. Furthermore, a comprehensive performance analysis of optical plastic materials demonstrated the viability of using these materials in the manufacture of the seeker’s optical structure. Our final optical system design boasts a focal length of 71.6mm and an F/# of 1, with the edge field chief ray telecentric maintained below 6mrad. In the operating temperature range, the stability of spot size is better than 0.4% and the maximum distortion of the full field of view is less than 0.5%. Notably, within a ±2° field of view, both the light spot linearity and energy response consistency meet the stringent requirements for precision guidance. The structural design methodology we employed, which focuses on minimizing primary aberrations, can be effectively applied to the optimization of catadioptric systems, thus serving as a valuable reference for the optical structure design of similar seekers.

As an advanced tissue optical imaging technology, time-domain diffuse optical imaging (TD-DOI) enables quantitative reconstruction of absorption and reduced scattering coefficients in biological tissues through time-correlated single photon counting (TCSPC) systems, thereby allowing precise assessment of critical physiological parameters such as tissue oxygen metabolism and blood perfusion. However, constrained by the inherent hardware complexity and high cost of TCSPC systems, current implementations face challenges in achieving scalable clinical applications requiring in-vivo multichannel dynamic monitoring. This study innovatively proposes a dual-channel differential hybrid trigger reference signal strategy. By integrating differential time-to-digital converter (TDC) devices with photon counting techniques, we have established a stable and reliable time point spread function (TPSF) measurement system that achieves sub-nanosecond precision (±50 ps) in calibrating the temporal delay between laser synchronization signals and emitted photon events. Experimental validation demonstrates that the developed system attains a temporal resolution of 55 ps. Under photon counting rates of 2.3×10⁴ photons/s, the TPSF fluctuation coefficient remains consistently below 1.35% (1 s integration time). Optical properties inversion on tissue phantoms reveal mean reconstruction errors of 5.39% for absorption coefficient and 4.34% for reduced scattering coefficient. This technological advancement significantly enhances the feasibility of multichannel parallel detection in TD-DOI systems. Particularly suited for biomedical applications, such as dynamic monitoring of cerebral cortical oxygen saturation, it establishes a technical foundation for developing next-generation wearable optical brain function imaging devices.

With the breakthrough progress of mid-wave and long-wave infrared hyperspectral imaging technology, the military hyperspectral imaging system, with its unique feature recognition capability and covert reconnaissance advantages, has demonstrated significant strategic value in the field of modern battlefield situational awareness, e.g., real-time target identification, anti-camouflage reconnaissance, and dynamic monitoring of global military targets. In this study, a dual-band Offner-type spectral imaging system operating in the mid-wave infrared (3.7−4.8 μm) and long-wave infrared (7.7−9.5 μm) is designed for aerial detection applications based on a 320×240-pixel dual-color cooled infrared detector. The system adopts a hybrid refractive and refractive-reflective optical structure, and realizes a three-field-of-view switching zoom function of 32 mm, 200 mm and 800 mm. The optical system adopts the Offner spectroscopic structure, which effectively suppresses the primary aberration of the system; secondly, through the introduction of the secondary imaging relay system, it achieves 100% cold diaphragm matching and significantly reduces the cold reflection effect. Experimental tests show that the system exhibits excellent imaging performance in all bands and at different focal lengths: at a characteristic frequency of 17 lp/mm, the modulation transfer function approaches the diffraction limit, and temperature changes have little effect on imaging quality; optical image quality meets design specifications. The optical system is characterized by wide spectral response, large magnification ratio (25×) and fast field of view switching. The spectral resolution reaches 25 nm, and its imaging quality and spectral resolution meet the technical requirements of aviation photoelectric reconnaissance, which has important application value in military reconnaissance, security monitoring and environmental monitoring.

Stray light interference in vehicular LiDAR systems can reduce the signal-to-noise ratio and degrade detection efficiency. To mitigate this issue, this paper proposed a surface scattering modeling method based on the spectral power density function and total integrated scattering, which fits the bidirectional reflectance distribution function (BRDF) for various material surfaces. The model calculation results were highly consistent with the measured BRDF data, verifying the effectiveness of the method. Based on this model, the study systematically analyzed the sources and propagation paths of stray light in the long-focal-length receiving optics of vehicular LiDAR, with specific attention to scattering from the housing's inner walls, lens edges, and spacer ring surfaces. According to the simulation results, this paper put forward a number of stray light suppression measures, such as using structural components made of low-scattering materials, coating anti-reflection films on lens surfaces, and applying light-absorbing ink to the non-optical areas of lenses, etc. Furthermore, from optical design, signal processing and engineering optimization, the stray light suppression level of this LiDAR receiving optical system was evaluated in multiple dimensions. The results of the experiment showed that the level of stray radiation in the optimized system was significantly reduced: the point source transmittance (PST) outside the imaging field of view was reduced from 1e+0 to 1e-5, the PST in the field of view was reduced from 1e+2 to 1e-1, and the stray light contrast with the target signal was controlled below 10e-4. Additionally, the intensity of the detected echo signal is significantly improved, thereby effectively enhancing the detection performance of the LiDAR. This study provides a theoretical model and practical solutions for stray light suppression in vehicle-mounted LiDAR, offering valuable references for the design and optimization of high-sensitivity optical systems.

To address the demand for large field-of-view and high compactness in lightweight AR glasses equipped with cameras, this study proposes an optical design method incorporating a curved image plane. First, based on Gaussian optics theory, the curved image plane imaging system is theoretically analyzed. The Petzval surface curvature characteristics of various optical configurations are derived, and the performance advantages of the curved image plane are highlighted through comparative simulations of dual systems. Then, a wide-angle and compact optical system is designed using a segmented multi-objective optimization strategy. Finally, image quality evaluation and tolerance analysis are performed on the designed system. The compact optical system comprises five aspheric plastic lenses and a rear-mounted filter. It features a focal length of 3.1 mm, a field of view (FOV) up to 80°, and a total system length of only 4.07 mm. The design results show that at 223 lp/mm, the modulation transfer function (MTF) exceeds 0.32 across all fields. The maximum RMS spot radius is 2.41 μm, with a distortion of only 2.5%, and the relative illumination remains above 45% across the entire field. This work lays a foundation for the application of curved sensors and offers a technical reference for the design of wide-angle compact lenses.

To evaluate the laser-induced damage effects on visible-light imaging systems under realistic operational conditions, a detector module comprising a filter and a back-illuminated CMOS sensor was employed as the target. This study investigates the damage mechanisms induced by nanosecond pulsed lasers at wavelengths of 532 nm and 1064 nm. Initially, a series of experiments were conducted to characterize the typical damage behaviors resulting from laser irradiation. To address the limitations in observing internal thermal and mechanical responses during the experiments, a finite element simulation model was developed to analyze the interaction between the laser and the detector. The simulation enabled visualization of temperature and stress concentration phenomena that are difficult to capture through direct observation, thus providing valuable reference data for damage thresholds. The results from both the experiments and simulations indicate that the dominant damage mechanism is coupled thermo-mechanical failure. The measured multi-stage damage thresholds were 30.06 mJ/cm², 38.93 mJ/cm², 56.20 mJ/cm², and 102.17 mJ/cm² for 532 nm laser irradiation, and 38.62 mJ/cm², 50.09 mJ/cm², 116.31 mJ/cm², and 137.73 mJ/cm² for 1064 nm irradiation.

During the research and development process of the scientific research project, it was found that the beam deviation angle formula of a Rochon Prism in classical optical literature (for negative crystals) was incorrect. Therefore, an accurate expression for the beam deviation angle of a Rochon Prism was derived (distributed for negative and positive crystals), and the problem of design in the optical systems containing a Rochon Prism in the scientific research projects was solved. In response to the problem of small angles between the output two beams of light in general a Rochon Prism products, the expressions for the deviation angles of a Rochon Prism composed of negative and positive crystals were analyzed and derived. In addition, the deviation angles of a Rochon Prism composed of different crystal materials were analyzed and the expression was derived. By calculating and comparing with actual data, it is known that the beam deviation angle of a Rochon Prism made of different crystal materials is significantly higher than that of a Rochon Prism made of the same crystal material. For applications in the ultraviolet band, provide a specific design example of a large beam deviation angle for a Rochon Prism composed of heterogeneous crystal materials. This type of a Rochon Prism is composed of heterogeneous crystal materials, and according to the appropriate crystal arrangement order, a relatively large beam deviation angle can be obtained under the limitation of reasonable crystal thickness, which is obviously beneficial for the structural design of the polarization instruments and equipments.

This study addresses the urgent demand for 1018 nm single-frequency seed sources in the field of Rydberg microwave measurements by developing a widely tunable 1018 nm single-frequency fiber laser with a linewidth of 810 Hz and a relative intensity noise below −140 dB/Hz.The laser employs a distributed Bragg reflector (DBR) structure with an 8-mm-long ytterbium-doped fiber and incorporates a high-stability active temperature control system and a piezoelectric ceramic (PZT)-based fast frequency tuning device. The temperature control range was from 10 °C to 80 °C, and the temperature fluctuation of the DBR resonance cavity was only ±0.0005 °C within 2 hours at 25 °C temperature control. After experimental testing, the laser maintains a single longitudinal mode output at 25°C, with a linewidth of 810Hz, a temperature tuning range of more than 0.9 nm, and a fast tuning range of the PZT up to 10 GHz, there is no mode-hopping phenomenon in the tuning process. The relative intensity noise of a single-frequency laser is −150 dB/Hz in the low frequency band of 1 kHz, and below −140 dB/Hz when the frequency is greater than 1.5 MHz. This result shows that the laser output is low noise while achieving wide tuning.

Catadioptric space cameras are widely used in space exploration, However, temperature variations can degrade their imaging performance. To address this issue, this paper presents an athermal design for a catadioptric space camera operating over a wide temperature range. Initially, the temperature effects on optical elements, mechanical structures, and other components were analyzed, and convenient methods for thermal aberration compensation are summarized. Subsequently, taking a camera with a spectral range of 400–1000 nm, a focal length of 525 mm, and an F-number of 3.5 as the design case, an athermal solution is developed. By selecting appropriate materials for the mirror substrates and support structures, and using fused silica as the single lens material to correct aberrations, the optical system maintains stable performance in space environments. Final simulation results confirm that the optimized camera maintains a Modulation Transfer Function (MTF) value above 0.4 at 77 lp/mm (Nyquist frequency) over a temperature range of –60°C to 150°C. The camera exhibits stable material properties, excellent imaging quality, and consistent performance under extreme temperatures. This design demonstrates significant potential for applications in space exploration and related fields.

The Savitzky-Golay (SG) filter, which employs polynomial least-squares approximations to smooth data and estimate derivatives, is widely used for processing noisy data. However, noise suppression by the SG filter is recognized to be limited at data boundaries and high frequencies, which can significantly reduce the signal-to-noise ratio (SNR). To solve this problem, a novel method synergistically integrating Principal Component Analysis (PCA) with SG filtering is proposed in this paper. This approach avoids the issue of excessive smoothing associated with larger window sizes. The proposed PCA-SG filtering algorithm was applied to a CO gas sensing system based on Cavity Ring-Down Spectroscopy (CRDS). The performance of the PCA-SG filtering algorithm is demonstrated through comparison with Moving Average Filtering (MAF), Wavelet Transformation (WT), Kalman Filtering (KF), and the SG filter. The results demonstrate that the proposed algorithm exhibits superior noise reduction capabilities compared to the other algorithms evaluated. The SNR of the ring-down signal was improved from 11.8612 dB to 29.0913 dB, and the standard deviation of the extracted ring-down time constant was reduced from 0.037 µs to 0.018 µs. These results confirm that the proposed PCA-SG filtering algorithm effectively improves the smoothness of the ring-down curve data, demonstrating its feasibility.

Due to the inability of manufacturing a single monolithic mirror at the 10-meter scales, segmented mirrors have become indispensable tools in modern astronomical research. However, to match the imaging performance of the monolithic counterpart, the sub-mirrors must maintain precise co-phasing. Piston error critically degrades segmented mirror imaging quality, necessitating efficient and precise detection. To address the limitations that the conventional circular-aperture diffraction with two-wavelength algorithm is susceptible to decentration errors, and the traditional convolutional neural networks (CNNs) struggle to capture global features under large-range piston errors due to their restricted local receptive fields, this paper proposes a method that integrate enhanced Young’s interference principles with a Vision Transformer (ViT) to detect piston error. By suppressing decentration error interference through two symmetrically arranged apertures and extending the measurement range to ± 7.95 μm via a two-wavelength (589 nm/600 nm) algorithm, this approach exploits ViT’s self-attention mechanism to model global characteristics of interference fringes. Unlike CNNs constrained by local convolutional kernels, the ViT significantly improves sensitivity to interferogram periodicity. The simulation results demonstrate that the proposed method achieves a measurement accuracy of 5 nm (0.0083λ₀) across the range of ± 7.95 μm, while maintaining an accuracy exceeding 95% in the presence of Gaussian noise (SNR ≥ 15 dB), Poisson noise (λ ≥ 9 photons/pixel), and sub-mirror gap error (E_gap ≤ 0.2) interference. Moreover, the detection speed shows significant improvement compared to the cross-correlation algorithm. This study establishes an accurate, robust framework for segmented mirror error detection, advancing high-precision astronomical observation.

In recent years, the demand for synchronous acquisition of three-dimensional (3D) shape and color texture has surged in fields such as cultural heritage preservation and healthcare. Addressing this need, this paper proposes a novel method for simultaneous 3D shape and color texture capture. First, a linear model correlating camera exposure time with grayscale values is established. Through exposure time calibration, the projected red, green and blue (RGB) light and white-light grayscale values captured by a monochrome camera are aligned. Then, three sets of color fringes are projected onto the object to identify optimal pixels for 3D reconstruction. And, three pure-color patterns are projected to synthesize the color texture. Experimental results show that this method effectively achieves synchronous 3D shape and color texture acquisition, offering high speed and precision. And using a monochrome camera avoids color crosstalk interference common in 3D reconstruction of colored objects.

A Yb:CaGd_0.33Y_0.625AlO₄ (Yb:CGYA) laser crystal of high optical quality has been successfully synthesized via the Czochralski method. The introduction of Gd³⁺ ions preserves the original structure and efficiently generates inhomogeneous broadening of the Yb³⁺ ion emission spectra. The fluorescence emission peak wavelength of the Yb:CGYA crystal is 1053 nm, and the corresponding measured full width at half-maximum is 93 nm. A tunable laser output ranging from 1017 nm to 1073 nm is achieved by using a birefringent filter, which represents the broadest tuning range reported in a short cavity to date. The compact laser offers great advantages for its applications around 1 μm.

The improved cross-correlation algorithm for the strain demodulation of Vernier-effect-based optical fiber sensor (VE-OFS) is proposed in this article. The algorithm identifies the most similar spectrum to the measured one from the database of the collected spectra by employing the cross-correlation operation, subsequently deriving the predicted value via weighted calculation. As the algorithm uses the complete information in the measured raw spectrum, more accurate results and larger measurement range can be obtained. Additionally, the improved cross-correlation algorithm also has the potential to improve the measurement speed compared to current standards due to the possibility for the collection using low sampling rate. This work presents an important algorithm towards a simpler, faster way to improve the demodulation performance of VE-OFS.

As an efficient passive anti-icing method, the superhydrophobic surface can reduce icing process on metals in low temperatures. However, the usual organic low-surface-energy decorations are often prone to age especially in harsh environments, leading to a decrease or complete failure of the anti-icing performance. Here, we adopt a method of femtosecond laser microstructuring to achieve inorganic superhydrophobic aluminum alloys through simultaneously modifying the surface profile and compositions. The obtained bionic anthill tribe structure with the low thermal conductivity, exhibits the superior delayed freezing time (803.3 s) and the low ice adhesion (16 μN) in comparison to the fluorosilane modified and bare Al surfaces. Moreover, such an inherently superhydrophobic metal surface also shows the exceptional environmental durability in anti-icing performance, which confirms the effectiveness of our superhydrophobic surface without the need for organic coatings.

Metalenses are subject to off-axis aberrations and material dispersion, which fundamentally limit their ability to achieve both wide field-of-view (FOV) and broad operational bandwidth in imaging detection systems. In this paper, an achromatic monolayer metalens with an elongated FOV in a continuous waveband is constructed using an elaborately designed metasurface. Leveraging a quadratic phase profile for large-field-of-view (FOV) detection, the metasurface unit structure transmission phase is subsequently optimized via particle swarm optimization (PSO) to achieve continuous band dispersion tuning. This approach consequently enables expanded operational bandwidth under wide-FOV conditions. For a monolayer metalens with a numerical aperture of 0.351, an achromatic focusing field covering a ±20° FOV is obtained within the continuous waveband from 0.55 μm to 0.65 μm. The maximum focal length deviation along the optical axis is 3.2 μm (~0.08 f₀), the incident angle detection deviation ≤ 1.34°. The proposed method can realize an achromatic monolayer metalens with an elongated FOV within a continuous waveband, which will have potential applications in lightweight and integrated optical imaging systems.

本文设计了一种由两个一端封堵的金属-绝缘体-金属（MIM）波导与一个的D形腔耦合组成表等离激元波导结构。使用有限元方法（FEM）模拟了该结构的传输特性、磁场分布以及折射率传感特性。在透射光谱中可以明显观察到多Fano共振现象。这些Fano共振是由于D形谐振腔的产生的共振离散态与一端封堵的MIM波导产生的连续状态之间相互耦合产生。通过系统地调整结构参数，研究了其对Fano共振调制的影响。此外，通过改变MIM波导中绝缘层的折射率研究了基于Fano共振折射率传感特性。结果表明，在第一个Fano共振峰处实现了最大1155 RIU/nm的灵敏度。这些研究对高灵敏度光子器件、微型传感器、未来新型片上传感的设计和研究提供了新的途径。

Metalens technology has been applied extensively in miniaturized and integrated infrared imaging systems. However, due to the high phase dispersion of unit structures, metalens often exhibits chromatic aberration, making broadband achromatic infrared imaging challenging to achieve. In this paper, six different unit structures based on chalcogenide glass are constructed, and their phase-dispersion parameters are analyzed to establish a database. On this basis, using chromatic aberration compensation and parameterized adjoint topology optimization, a broadband achromatic metalens with a numerical aperture of 0.5 is designed by arranging these six unit structures in the far-infrared band. Simulation results show that the metalens achieves near diffraction-limited focusing within the operating wavelength range of 9-11 µm, demonstrating the good performance of achromatic aberration with flat focusing efficiency of 54% - 58% across all wavelengths.

As a potential alternative for energy in quantum regime, a quantum battery inevitably undergoes the process where the extracted work deteriorates due to the environmental decoherence. To inhibit the energy dissipation, we have put forward a scheme of a moving atom battery in a lossy cavity coupled to a structured environment. We investigate the dynamics of the maximally extracted work called the ergotropy by the open quantum system approach. It is found out that the decay of quantum work is significantly retarded in the non-Markovian environment. In contrast to the static case, the storage performance of the quantum battery is improved when the atom is in motion. The effect of energy preservation becomes more pronounced at higher velocities. Both the momery effect and motion control can play a positive role in extending the discharge lifetime. In addition, we have investigated the effects of environmental temperature, random noises, and quantum entanglement. These present results provides a feasible protocol for the open quantum battery.

Diffractive waveguides have emerged as a particularly promising solution for augmented reality (AR) near-eye display technologies. These waveguides are characterized by their light weight, wide field of view, and large eyebox. However, most commercially available AR waveguide simulation software has been developed by foreign companies, and there has been little advancement in domestic 3D visualization software for optical waveguide design and simulation. The present study is, to the best of our knowledge, the first to develop 3D visualization module for optical waveguide design and simulation based on ray-field tracing. Using this module, a two-dimensional exit-pupil-expansion diffractive waveguide has been designed, and a systematic design workflow is demonstrated. The workflow integrates k-domain analysis, automated layout generation of grating regions within the optical waveguide, waveguide optimization, and ray-field tracing simulations, thereby establishing a cohesive methodology for device development. The module extends beyond single-waveguide simulations to system-level analyses of near-eye displays, including micro-displays, micro-projectors, and human eye models. By bridging the microscopic and macroscopic scales, it enables holistic performance evaluation of AR optical systems, highlighting their capabilities and technical advantages. This module provides a robust and efficient platform for domestic optical engineers to advance the design and simulation of optical waveguides, thereby accelerating the industrialization and technological advancement of AR optics in China.

To improve the processing efficiency of large-aperture optical components, a multi-robot, multi-tool collaborative processing method was proposed. A collaborative layout that has been tailored to the optical components was designed, and three feasible trajectories were simulated for analysis. The discrete simulation results were then used to establish principles for selecting trajectory parameters. To address the limitation of discrete simulation in capturing the influence of trajectory continuity on the surface map, an integral removal function model adapted to the motion mode was introduced. Furthermore, a collaborative machining obstacle avoidance strategy was developed. The experimental results obtained using the optimal trajectory demonstrated that with an initial surface shape of PV=18.310λ (λ=632.8 nm) and RMS=1.788λ, the final surface achieved PV=4.873λ and RMS=1.113λ. In addition, within the effective range of 120 mm diameter, PV=4.661 λ, RMS=0.857λ, converged to PV=2.465λ and RMS=0.622λ after processing. The total execution time was 3.943 hours, with the maximum execution time for a single processing unit being 2.041 hours, representing a 1.93-fold improvement over single-tool processing. This method significantly enhances processing efficiency, ensures surface shape accuracy, and holds great potential for the manufacturing of large-aperture optical components.

Atmospheric coherence length is a critical indicator of the impact of atmospheric turbulence on free-space optical communication links. This paper proposes a novel strategy for measuring atmospheric coherence length by utilizing extended targets as the information source. Specifically, the method integrates the wavefront structure function approach with the extended target offset algorithm to directly estimate the atmospheric coherence length. Traditional methods, such as the Differential Image Motion Monitor (DIMM), typically rely on guide star targets, which are difficult to set appropriately in horizontal communication links, thereby limiting their effectiveness in practical applications. In contrast, employing extended targets as direct detection targets provides a feasible solution for measuring atmospheric coherence length. The paper first reviews the principles and current research status of mainstream algorithms, emphasizing the reliance of existing algorithms on guide star targets and their limitations in horizontal links. Subsequently, we propose a new measurement scheme that combines the improved normalized cross-correlation algorithm with the wavefront structure function method to estimate atmospheric coherence length under extended targets scenarios. In comparison to traditional measurement methods, our approach enables coherence length measurement based on extended targets in horizontal links, thereby significantly reducing system complexity and equipment costs. To validate the effectiveness and measurement accuracy of the proposed method, both simulations and experiments were designed and conducted. The results demonstrate that the coherence length values measured by this method are highly consistent with those obtained using the DIMM method and the wavefront phase variance method, with a measurement accuracy error of approximately 4%. This indicates that the proposed method can effectively assess atmospheric coherence length, thereby providing a valuable reference for enhancing the reliability of free-space laser communication systems.

Stripe projection technology is widely used in 3D measurement and surface morphology reconstruction, where phase quality is a critical determinant of measurement accuracy. However, the nonlinear relationship between input and output light intensity is a major source of phase error. To address this issue, this paper introduces a novel system nonlinear active correction method. This method captures the variation pattern between input and output light intensity by projecting a small number of uniform gray-scale images onto a standard plane. This pattern is then integrated with active system nonlinear correction to construct a system nonlinear model based on the input-output light intensity variation. Genetic algorithms are used to optimize the coding values, which are then used to actively correct the projected fringes via fringe coding. The corrected fringes effectively reduce the influence of nonlinear effects, thereby significantly improving the quality of phase acquisition. To validate the proposed method, computer simulations were performed using three-step phase shifting. The results showed an 88% reduction in the standard error and an 85.5% reduction in the maximum error. In actual standard plane experiments, the corrected standard phase error decreased from 0.0706 rad to 0.0168 rad, and the maximum phase error decreased from 0.4129 rad to 0.0960 rad. In the face plaster model experiments, the corrected standard phase error decreased from 0.0472 rad to 0.0102 rad, and the maximum phase error decreased from 0.2990 rad to 0.2408 rad. In 3D reconstruction of complex morphology plaster models of human faces, the surface quality was significantly improved, and the water ripple effect, which affects the phase quality, was significantly reduced. Compared with existing large-step phase-shifting methods, the proposed method not only achieves high-quality phase acquisition accuracy, but also offers clear advantages in terms of required data volume and operational convenience, demonstrating broad application potential.