Journals >Laser & Optoelectronics Progress
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2025
Volume: 62 Issue 7
22 Article(s)
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Atmospheric Optics and Oceanic Optics
Neural Network Inversion Method for Atmospheric Temperature and Relative Humidity Profiles Based on FY-3E/HIRAS
Yike Zou, Ying Wu, Jingwen Ma, Yuanyuan Huang... and Qijia Fu|Show fewer author(s)
Using the observations made by the hyperspectral infrared atmospheric sounder (HIRAS) carried on the FY-3E polar orbiting meteorological satellite, the back propagation neural network (BPNN) method is employed to conduct research on the inversion of atmospheric temperature and relative humidity vertical profiles in theUsing the observations made by the hyperspectral infrared atmospheric sounder (HIRAS) carried on the FY-3E polar orbiting meteorological satellite, the back propagation neural network (BPNN) method is employed to conduct research on the inversion of atmospheric temperature and relative humidity vertical profiles in the East China region. An atmospheric temperature and humidity inversion model is constructed, and the parameters are optimized to obtain a network model configuration with high inversion accuracy, resulting in all-weather, high-precision atmospheric temperature and relative humidity profile. According to the results, the following conclusions can be drawn. 1) Temperature inversion results of the model have a mean error (ME) between -1.00 K and 1.00 K at each pressure layer, except that the absolute value of ME in the lower layer of the cloudy sky is greater than 1.00 K. The validation experiment conducts on ERA5 data has root mean square error (RMSE) between 0 K and 2.00 K for most pressure layers, except for ~2.50 K at the 925?950 hPa layer, the minimum RMSE corresponds to the 200?500 hPa, indicating higher temperature inversion accuracy in the upper atmosphere. 2) For the inversion of atmospheric relative humidity, the ME of the lower and upper atmosphere is larger, whereas that of the middle atmosphere is smaller; RMSE is larger in the middle layers and smaller in the lower and upper layers. 3) Compared to clear sky condition, the accuracy of temperature and relative humidity inversion models under cloudy sky condition is slightly lower. 4) The deviation of the temperature and relative humidity inversion results from the sounding data is slightly greater than the deviation from the ERA5 data although the trend of error with height variation is similar. The HIRAS data generally performs well in inverting the temperature and relative humidity of clear and cloudy skies, with high inversion accuracy. Therefore, this study has important reference value for inversion methods and techniques of atmospheric temperature and relative humidity, providing useful insights for future related research..
Laser & Optoelectronics Progress
- Publication Date: Apr. 10, 2025
- Vol. 62, Issue 7, 0701001 (2025)
Detectors
Simulation Design and Testing of Gallium Oxide Ultraviolet Detector Based on Monte Carlo Method
Shuxiang Lu, and Zhihao Zhang
Gallium oxide (Ga2O3) materials possess excellent optoelectronic properties in the ultraviolet region and are widely used in blind detection. In this study, a metal-semiconductor-metal geometric model commonly used in Ga2O3 detectors is constructed based on the Monte Carlo method using the Geant4 software. The effects Gallium oxide (Ga2O3) materials possess excellent optoelectronic properties in the ultraviolet region and are widely used in blind detection. In this study, a metal-semiconductor-metal geometric model commonly used in Ga2O3 detectors is constructed based on the Monte Carlo method using the Geant4 software. The effects of Ga2O3 thickness and other parameters on the detection efficiency are analyzed. Based on the simulation results, a Ga2O3 ultraviolet detector prototype is designed, and experimental verification is conducted subsequently. The designed detector has a responsivity of 4.545 mA/W at zero bias voltage under 254 nm ultraviolet light with an intensity of 110 μW/cm2, and a detection rate of 2.54×1012 cm·Hz1/2/W. These results indicate that the detector can effectively detect weak ultraviolet signals..
Laser & Optoelectronics Progress
- Publication Date: Apr. 10, 2025
- Vol. 62, Issue 7, 0704001 (2025)
Research on Stray Light Suppression of Collimator for Hartmann Detectors Calibration
Ziwen Song, Huangke Zhang, Wenkai Shi, Yilong Qian... and Zhaoliang Cao|Show fewer author(s)
To obtain high-quality plane waves, an diaphragm is designed to reduce the stray light caused by reflection or scattering from the tube wall of the collimator. First, a transmission model is established for the collimator, and the spots are simulated at different positions. Second, the diaphragm is simulated to analyzeTo obtain high-quality plane waves, an diaphragm is designed to reduce the stray light caused by reflection or scattering from the tube wall of the collimator. First, a transmission model is established for the collimator, and the spots are simulated at different positions. Second, the diaphragm is simulated to analyze the influence of diaphragm thickness and cone angle on the stray light, thereby determining the appropriate parameters. Finally, the diaphragm is placed inside the collimator, and the light spot is compared with no diaphragm installed. Results indicate that without the diaphragm there is significant stray light, which overlaps the parallel light at a distance of 400 mm. After installing the diaphragm, stray light is not observed around the parallel beam, and a high-quality plane wave is obtained at 200 mm. Results indicate that stray light is effectively suppressed using the designed diaphragm. This study provides a reference scheme for suppressing stray light of the collimator during the calibration of Hartmann detectors..
Laser & Optoelectronics Progress
- Publication Date: Apr. 10, 2025
- Vol. 62, Issue 7, 0704002 (2025)
Blind Pixel Detection Method for Infrared Detector Based on Surface Difference Value and Noise
Rongxing Li, Jie Guo, Fangyu Xu, and Xiaochong Shi
Currently, the detection of blind pixel in infrared detectors is typically conducted using the national standard method, Measuring Methods for Parameters of Infrared Focal Plane Arrays (GB/T 17444—2013). However, this method may result in inaccuracies in identifying blind pixels. To enhance the accuracy of blind pixelsCurrently, the detection of blind pixel in infrared detectors is typically conducted using the national standard method, Measuring Methods for Parameters of Infrared Focal Plane Arrays (GB/T 17444—2013). However, this method may result in inaccuracies in identifying blind pixels. To enhance the accuracy of blind pixels detection in infrared detectors, a blind pixel detection method based on the surface difference value and noise is proposed based on the national standard method. First, the causes of misjudgment associated with the national standard method are examined. Next, two surfaces are approximately fitted using effective pixel data, and the difference between these surfaces is used to establish specific dead pixel judgment criteria for individual pixels, enabling precise selection of dead pixels. Furthermore, by analyzing noise within infrared images, overheated pixels are also detected. The combined results of detected dead and overheated pixels provide the total number of blind pixels. Finally, comparative experiments involving various blind pixel detection methods demonstrate that the proposed method achieves a higher detection accuracy than the national standard method..
Laser & Optoelectronics Progress
- Publication Date: Apr. 10, 2025
- Vol. 62, Issue 7, 0704005 (2025)
Fiber Optics and Optical Communications
Side-Axis Alignment of Polarization-Maintaining Fibers Based on Scattering Patterns
Qin Yue, Jiongming Ye, Dunzhi Wang, and Yang Chen
A side alignment technique for polarization-maintaining fibers using the forward scattering pattern of a narrow-linewidth helium-neon laser is proposed. By rotating the fiber axis and observing changes in the scattering pattern, the fast and slow axes of the polarization-maintaining fiber can be precisely positioned. TA side alignment technique for polarization-maintaining fibers using the forward scattering pattern of a narrow-linewidth helium-neon laser is proposed. By rotating the fiber axis and observing changes in the scattering pattern, the fast and slow axes of the polarization-maintaining fiber can be precisely positioned. This technology addresses the inefficiencies and inaccuracies of traditional methods in measuring bow-tie or small-diameter polarization-maintaining fibers, providing essential support for their application in communication and sensing fields. Through experiments, the relationship between the rotation angle of the polarization-maintaining fiber and the intensity of the scattering pattern is examined.Results reveal that rotation alters the azimuth angle of the fast and slow axes, leading to corresponding changes in the scattering pattern's position. The analysis of the relationship between the rotation angle and scattering pattern reveal that the broad peak characteristic value is a more accurate and reliable metric for positioning the fast and slow axes of polarization-maintaining fibers. In addition, the effects of laser and fiber positioning on scattering patterns are examined. The Y-axis position offsets are particularly sensitive to the scattering patterns, whereas the fiber-to-light-screen distance significantly influences the spacing between scattering patterns. An experimental platform is constructed to validate the universality and practicality of broad peak characteristic values for fast and slow axis positioning in polarization-maintaining fibers..
Laser & Optoelectronics Progress
- Publication Date: Apr. 10, 2025
- Vol. 62, Issue 7, 0706001 (2025)
Instrumentation, Measurement and Metrology
High-Sensitivity Detection for Uric Acid Based on Double-F Multifrequency Resonant Metamaterial Sensor
Guocui Liu, Zhen Sun, Tingting Yuan, Xujun Xu... and Yong Du|Show fewer author(s)
Uric acid is the final oxide of purine metabolism in the body and is one of the serum markers of inflammation. Persistent elevation of uric acid levels in serum can cause a series of diseases in the human body. Conventional methods for detecting uric acid have the disadvantages of expensive analytical reagents, and cumUric acid is the final oxide of purine metabolism in the body and is one of the serum markers of inflammation. Persistent elevation of uric acid levels in serum can cause a series of diseases in the human body. Conventional methods for detecting uric acid have the disadvantages of expensive analytical reagents, and cumbersome and complicated chemical analysis. Detection based on terahertz metamaterial sensors is label-free and nondestructive, requires only a minute amount of reagents, does not damage analytes, and offers a high detection speed. A double-F multifrequency resonant metamaterial sensor with a maximum sensitivity of 160 GHz/RIU (RIU is a unit of refractive index) is proposed, which can be applied to high-sensitivity detection of uric acid. Different concentrations of uric acid solutions can be detected using this sensor. Results show that the lowest detection limit of the proposed sensor for uric acid solution is 0.001 g/L, which is lower than the lowest level of uric acid in a healthy human body. Thus, it is expected to be used in the detection of diseases..
Laser & Optoelectronics Progress
- Publication Date: Apr. 10, 2025
- Vol. 62, Issue 7, 0712001 (2025)
Evaluation Method for Error Calibration of Laser Tracking Measurement Systems
Shixiong Wen, Tengfei Wu, and Haochen Qu
In response to the high-precision measurement requirements of laser tracking measurement systems, this study analyzed their kinematic model and investigated a calibration method for the control field network. Based on the uncertainty propagation law of the implicit function model of the objective function, a structuralIn response to the high-precision measurement requirements of laser tracking measurement systems, this study analyzed their kinematic model and investigated a calibration method for the control field network. Based on the uncertainty propagation law of the implicit function model of the objective function, a structural error calibration evaluation model was developed. The influence of the number of transfer stations and the layout of calibration points on the calibration effect of structural errors was simulated and analyzed. Furthermore, a calibration and evaluation field was constructed for experimental verification. Experimental results demonstrate that the calibration accuracy of structural error parameters under different layouts aligns with the measurement accuracy of the evaluation field coordinates. When the dimensionless mean of the uncertainty of the structural error parameter calibration calculated using the structural error calibration evaluation model increases from 21.90 to 410.96, the root mean square error of the evaluation field coordinates increases from 0.2910 to 2.2365 mm. These findings confirm that the proposed method effectively evaluates the calibration effect of the structural error network in laser tracking measurement systems..
Laser & Optoelectronics Progress
- Publication Date: Apr. 10, 2025
- Vol. 62, Issue 7, 0712002 (2025)
Rotating Measurement Method for Inner Hole Parameters with Large Depth-to-Diameter Ratio Based on Spectral Confocal Principle
Rui Ma, Borong Wu, Baowen Li, and Xinghui Li
This study addresses the challenges of measuring inner hole parameters in workpieces with large depth-to-diameter ratios by proposing a rotating measurement method based on spectral confocal principles. First, a measuring system tailored for inner hole parameters with a large depth-to-diameter ratio is designed and conThis study addresses the challenges of measuring inner hole parameters in workpieces with large depth-to-diameter ratios by proposing a rotating measurement method based on spectral confocal principles. First, a measuring system tailored for inner hole parameters with a large depth-to-diameter ratio is designed and constructed. An optical confocal probe that allows for non-contact measurements is next mounted at the front end of a hollow, long, straight guide rod. This guide rod is driven by an X-RXmotion module that facilitates the rotation of the optical confocal probe in the direction of the hole's depth. Then, 10 groups of experiments are conducted at various speeds to collect inner diameter data from the spectral confocal probe, which rotates forward and reversely alternately three times each within an inner hole workpiece characterized by a depth-to-diameter ratio of 12.52 and depth of 222 mm. Finally, algorithms are developed to calculate the diameter, center coordinates, and perpendicularity of the inner hole by fitting the contour of the inner hole workpiece using the inverse least squares method. The analysis also considered the effects of moving speed on the measurement accuracy of the inner hole parameters. It is verified by comparison experiment that the system has high measuring accuracy. The measuring value of hole inner diameter fluctuates within ±2 μm and the perpendicularity within 50 μm under low speed, while those are within ±7 μm and 80 μm under high speed. The results align closely with the calibration values for large deep-diameter workpieces, thus demonstrating the effectiveness of the proposed method and system..
Laser & Optoelectronics Progress
- Publication Date: Apr. 10, 2025
- Vol. 62, Issue 7, 0712003 (2025)
Lasers and Laser Optics
Top-Emitting Vertical-Cavity Surface-Emitting Lasers for Substrate Heat Dissipation
Chunpeng Yang, Bifeng Cui, Jingyu Feng, Zhongbiao Chen... and Bozhao Yan|Show fewer author(s)
Traditional top-emitting vertical-cavity surface-emitting lasers (VCSELs) exhibit a long distance between the source region and heat sink, and internal heat conduction of the device is difficult, resulting in limited output power of both single-tube and array devices. To address these limitations, this study proposes aTraditional top-emitting vertical-cavity surface-emitting lasers (VCSELs) exhibit a long distance between the source region and heat sink, and internal heat conduction of the device is difficult, resulting in limited output power of both single-tube and array devices. To address these limitations, this study proposes a top-emitting VCSEL with a heat dissipation hole on the substrate. This hole is located directly below the countertop and is filled with high-thermal-conductivity materials, enabling rapid heat transfer from within the device. This design ensures mechanical support for the entire structure while improving the heat dissipation capacity. Simulation results indicate that the thermal flip power of the VCSEL device with a heat dissipation hole is 9.54 mW, representing a 36.4% increase compared to VCSEL devices without a heat dissipation hole. VCSEL devices with an oxidation aperture of 12 μm are prepared and tested under a duty cycle of 0.6%. The peak power of the VCSEL with a heat dissipation hole reaches 9.59 mW, which is 31% higher than that of the VCSEL without a heat dissipation hole..
Laser & Optoelectronics Progress
- Publication Date: Apr. 10, 2025
- Vol. 62, Issue 7, 0714003 (2025)
Thermodynamic Study of Overlap Process for Molten Channels in Selective Laser Melting of AlSi10Mg
Xiaonan Ni, Zijian Hu, Yanxun Liang, Ansen Wang... and Xin Deng|Show fewer author(s)
To clarify the control mechanism of scanning spacing on forming quality in selective laser melting (SLM), multiphysics numerical simulation combined with experiments is performed to investigate the mechanism underlying the effect of scanning spacing on the thermodynamic behavior of adjacent melting overlap process. ResTo clarify the control mechanism of scanning spacing on forming quality in selective laser melting (SLM), multiphysics numerical simulation combined with experiments is performed to investigate the mechanism underlying the effect of scanning spacing on the thermodynamic behavior of adjacent melting overlap process. Results show that the preheating effect of the previous scan channel can increase the base temperature and peak temperature of the subsequent scan channel, although this effect weakens as the scanning spacing increases. When the scanning spacing is extremely small (≤50 μm), the temperature of the first zone reaches 1168 K and remelting occurs during the second scanning channel, whereas a larger scanning spacing (≥90 μm) increases the temperature gradient of the fuse and reduces the cooling rate of the scan channel. During weld bonding, the flow rate of the molten pool near the sintered side is sufficient and the melt velocity distribution is uniform, whereas the opposite is observed for the molten pool near the unsintered side. When the scanning spacing is 70 μm, the melt flow velocity difference between the two sides of the molten pool is the smallest, which is more conducive to the stability of the molten pool and the construction quality of SLM, and the relative density and Vickers hardness are 98% and 131.3 HV, respectively. The sweep-spacing parameter should be coordinated with other process parameters to improve the forming quality while ensuring the overlap rate..
Laser & Optoelectronics Progress
- Publication Date: Apr. 10, 2025
- Vol. 62, Issue 7, 0714006 (2025)
Nonlinear Optics
Unconventional Photon Blockade Under the Combined Effects of Second-Order Nonlinearity and Two-Photon Absorption Environment
Zhiqiang Zhang
Utilizing both analytical and numerical methods, this study examine unconventional photon blockade in a second-order nonlinear system influenced by two-photon absorption environment. First, we derive the optimal conditions necessary for achieving unconventional photon blockade through analytical methods. The numerical Utilizing both analytical and numerical methods, this study examine unconventional photon blockade in a second-order nonlinear system influenced by two-photon absorption environment. First, we derive the optimal conditions necessary for achieving unconventional photon blockade through analytical methods. The numerical results for the equal-time second-order correlation function are then presented. Results indicate that unconventional photon blockade is present in the second-order nonlinear system affected by two-photon absorption environment, with the analytical optimal conditions aligning closely with the numerical results. Finally, an analytical expression for the equal-time second-order correlation function is provided and compared with the numerical results. The comparison reveals that the theoretical predictions for the equal-time second-order correlation function are largely consistent with the numerical results, and in regions of discrepancy, the theoretical values tend to be lower than the numerical ones. This inconsistency arises because the analytical calculations truncate the system's Hilbert space to two-photon excitation. In addition, the width of the photon blockade window increases with stronger external driving forces, whereas it decreases with greater second-order nonlinear interaction strength. These findings offer valuable theoretical guidance for the experimental observation and practical application of photon blockade in this system..
Laser & Optoelectronics Progress
- Publication Date: Apr. 10, 2025
- Vol. 62, Issue 7, 0719001 (2025)
Optical Design and Fabrication
Design of Precision Temperature Control System for Trace CO Detection Employing TDLAS
Jiali Feng, Zhipeng Wei, Lipeng Sun, Jilong Tang... and Qihang Bao|Show fewer author(s)
The trace CO concentration detection system based on tunable diode laser absorption spectroscopy (TDLAS) technology presents low detection accuracy owing to interference from various environmental factors. Temperature fluctuations affect the responsivity and dark current of the photodetector, thus causing a drift in thThe trace CO concentration detection system based on tunable diode laser absorption spectroscopy (TDLAS) technology presents low detection accuracy owing to interference from various environmental factors. Temperature fluctuations affect the responsivity and dark current of the photodetector, thus causing a drift in the detector's output signal, which consequently affects the accuracy of CO detection. Hence, a high-precision constant-temperature control system with a wide temperature range is designed in this study. The effect of temperature on the photodetector's output signal is analyzed based on both the responsivity and dark current of the photodetector. Subsequently, a high-precision constant-temperature control drive module is designed using a relay feedback self-tuning proportional-integral-derivative adjustment algorithm, dual-channel voltage acquisition, and an improved comprehensive Kalman filter algorithm. Experimental results show that this high-precision constant-temperature control system can achieve a temperature-control accuracy of ±0.005 °C in both high- and low-temperature environments..
Laser & Optoelectronics Progress
- Publication Date: Apr. 10, 2025
- Vol. 62, Issue 7, 0722001 (2025)
Design and Research of Broadband Electromagnetic Wave Polarization Conversion and Beam Steering Metasurfaces
Lu Wang, Jiang Wang, Hongying Tang, and Xiaobing Yuan
As a key technology in the fields of future mobile communications and antenna systems, electromagnetic wave polarization based on metasurfaces has attracted widespread interest. However, in the current realm of polarization conversion metasurfaces, existing research still encounters challenges such as low operating freAs a key technology in the fields of future mobile communications and antenna systems, electromagnetic wave polarization based on metasurfaces has attracted widespread interest. However, in the current realm of polarization conversion metasurfaces, existing research still encounters challenges such as low operating frequencies, limited bandwidth, low conversion efficiency, and limited functionality. This paper presents the design of two types of reflective metasurface structures: a broadband electromagnetic wave polarization conversion metasurface and a beam steering metasurface. Specifically, by integrating anisotropic principles, we design a polarization conversion metasurface unit composed of a central "C"-shaped metallic aperture and diagonal "L"-shaped metallic strips that can achieve broadband linear polarization conversion from 22.5 to 48.5 GHz. Building upon this structure, the beam steering metasurface incorporates phase modulation principles; through the altering of the opening angle and rotation angle of the aperture rings, specific phase gradients between units can be achieved, thereby enabling beam steering functionality at 30 GHz based on the generalized Snell's law. Simulation results closely align with theoretical expectations, thoroughly validating the functionalities of the designed metasurfaces in polarization conversion and beam steering. This approach effectively addresses the limitations of existing studies and demonstrates promising application prospects in future communication systems and antenna technologies..
Laser & Optoelectronics Progress
- Publication Date: Apr. 10, 2025
- Vol. 62, Issue 7, 0722003 (2025)
Simulation on Influence Mechanism of Mid-Spatial Frequency Error Smoothing in Viscoelastic Conformal Vibration Polishing Tools
Zhijie Zhang, Yuchuan Chen, Yunfei Zhang, Xinquan Zhang... and Kuo Hai|Show fewer author(s)
Conformal vibration polishing is an effective mid-spatial frequency (MSF) error smoothing process method for complex surfaces, and it has broad application prospects in the processing of optical elements in many major optical engineering projects. In this study, a finite element based simulation method is proposed to aConformal vibration polishing is an effective mid-spatial frequency (MSF) error smoothing process method for complex surfaces, and it has broad application prospects in the processing of optical elements in many major optical engineering projects. In this study, a finite element based simulation method is proposed to address the issues of unclear polishing mechanism and unclear process rules in vibration polishing of viscoelastic tools. Furthermore, the influence mechanism of flexible layer material properties, polishing pressure, and vibration frequency on mid-spatial frequency error smoothing in vibration polishing is examined. Additionally, the influence law on the mid-spatial frequency error smoothing ability is obtained. Through simulation analysis and experimental verification, the following conclusions are drawn: the mid-spatial frequency error smoothing ability of conformal vibration polishing initially increases and then decreases with the increase in the elastic modulus of the viscoelastic material, increases with the increase in polishing pressure, and initially stabilizes and then increases with the increase in vibration frequency. When the maximum elastic modulus of the viscoelastic body is within 9?12 MPa, the polishing pressure is between 800?1100 Pa, and the vibration frequency is between 20?30 Hz. Furthermore, the mid-spatial frequency error smoothing effect of vibration polishing is optimal, and it also has exhibits low-spatial frequency conformal ability..
Laser & Optoelectronics Progress
- Publication Date: Apr. 10, 2025
- Vol. 62, Issue 7, 0722004 (2025)
Efficient Metasurface Design Method Based on Super-Resolution Reconstruction Technology
Kaiwei Zhang, Hongyun Gao, Haifei Lü, Yuanjia Xia, and Guobing Chen
Metasurfaces offer unique advantages for controlling incident electromagnetic waves. However, the design of a complete metalens involves extensive modeling and analysis of numerous unit structures. This process is both time-consuming and challenging, particularly when aligning phase distributions with desired outcomes,Metasurfaces offer unique advantages for controlling incident electromagnetic waves. However, the design of a complete metalens involves extensive modeling and analysis of numerous unit structures. This process is both time-consuming and challenging, particularly when aligning phase distributions with desired outcomes, which poses significant limitations to simulation efficiency. In this study, we propose a deep learning-based super-resolution reconstruction model that exploits a generative adversarial network for metasurface design. The proposed model enables rapid and precise upscaling of phase-geometric arrays, generating unit structures with higher data density in the output phase. By training on 9000 sample sets, the proposed model achieves a prediction accuracy of 95.17% when upscaling a 60 pixel × 60 pixel phase-geometric array to 120 pixel × 120 pixel. To validate its feasibility, we design a visible-light achromatic metalens using the predicted phase-geometric array of typical achromatic metalens unit structures. This design is verified by simulation. The results demonstrate that the proposed deep learning model significantly reduces simulation time and enhances accuracy compared to traditional simulation and interpolation methods. The proposed model also offers an efficient approach for the initial design and selection of metasurface units, providing a scalable solution for accelerated computation and data expansion in electromagnetic wave control based on a generative adversarial network..
Laser & Optoelectronics Progress
- Publication Date: Apr. 10, 2025
- Vol. 62, Issue 7, 0722005 (2025)
Dual-Band Slot Antenna Design Based on Substrate Integrated Waveguide
Wenbo Yang, and Yubin Lu
This paper presents a substrate integrated waveguide (SIW) cavity-backed slot antenna for dual-band operation. By etching a pair of triangular complementary ring slots in the antenna's back cavity for radiation, these slots can effectively excite narrow-gap hybrid modes inside the SIW cavity. One of the modes is shThis paper presents a substrate integrated waveguide (SIW) cavity-backed slot antenna for dual-band operation. By etching a pair of triangular complementary ring slots in the antenna's back cavity for radiation, these slots can effectively excite narrow-gap hybrid modes inside the SIW cavity. One of the modes is shifted upward in the lowest mode (TE120 or TE210 mode) and the other is shifted downward in the highest mode (TE320 or TE230 mode). The two modes appear paired together, which significantly improves antenna performance. The prototype of this antenna is fabricated on a low-cost substrate via printed-circuit-board technology. Simulation results show that the antenna operates in two frequency bands of 11.80?12.50 GHz (0.70 GHz) and 14.50?15.00 GHz (0.50 GHz). It resonates at frequencies of 12.00 GHz and 14.80 GHz, with peak gains of 6.40 dBi and 4.90 dBi, respectively. Additionally, this antenna features a high gain and a stable unidirectional radiation pattern..
Laser & Optoelectronics Progress
- Publication Date: Apr. 10, 2025
- Vol. 62, Issue 7, 0722006 (2025)
OPTOELECTRONICS
Research on Influence of Spatial Resolution in EBCMOS Proximity Region
Bei Jiang, Jiatong Zheng, De Song, and Weijun Chen
To obtain high-resolution electron bombarded complementary metal oxide semiconductor (EBCMOS) imaging devices, the influence of spatial resolution for EBCMOS proximity region is studied. The theoretical calculation model for spatial resolution in EBCMOS devices proximity region is established according to the principleTo obtain high-resolution electron bombarded complementary metal oxide semiconductor (EBCMOS) imaging devices, the influence of spatial resolution for EBCMOS proximity region is studied. The theoretical calculation model for spatial resolution in EBCMOS devices proximity region is established according to the principle of Fourier transform and electromagnetic fields. Effects of illumination, proximity distance, and proximity voltage on resolution are studied. The diffusion diameter of photoelectrons reaching the back-side bombarded CMOS (BSB-CMOS) surface can be reduced by reducing the proximity distance and increasing the proximity voltage, which will result in higher spatial frequency. The electron focusing and resolution will not varied when the magnitude of illumination is changed. When the proximity distance is 100 μm and proximity voltage is 3000 V, the electron beam diffusion diameter can be reduced to 10 μm, and the limit resolution can be increased to 127.27 lp/mm. This structure can effectively improve the resolution of the EBCMOS proximity region. Therefore, the research on the influence of spatial resolution in EBCMOS proximity region will provide a theoretical support for optimizing proximity structures and improving EBCMOS resolution..
Laser & Optoelectronics Progress
- Publication Date: Apr. 10, 2025
- Vol. 62, Issue 7, 0725001 (2025)
Physical Optics
Higher-Order Singularity Based on Three-Dimensional Non-Hermitian System
Miaomiao Zhang, Yan Zhang, Jiale Zhang, and Jing Chen
Non-Hermitian systems are garnering attention in optics, electricity, acoustics, and other fields owing to their distinctive physical phenomena and promising applications. We explores the higher-order singularities in three-dimensional non-Hermitian systems. We also analyze the effects of these singularities on the eneNon-Hermitian systems are garnering attention in optics, electricity, acoustics, and other fields owing to their distinctive physical phenomena and promising applications. We explores the higher-order singularities in three-dimensional non-Hermitian systems. We also analyze the effects of these singularities on the energy response of the systems. We design and build a three-dimensional resonator array circuit, simulating its gain and loss by incorporating positive and negative resistances to establish a system constructed from repeated minimal unit cells. Through an analysis of the eigenvalues of the Hamiltonian operator and phase diagrams in the parameter space, the generation mechanism and evolution behavior of singularities in the system are elucidated. LTspice simulation results indicate that higher-order singularities significantly enhance the energy (voltage) response of the system, particularly when the circuit contains a specific number of unit cells, which can markedly increase the response speed. This finding provides new directions for optimizing sensor design and highlights the important application potential of higher-order singularities in non-Hermitian systems for improving the system performance..
Laser & Optoelectronics Progress
- Publication Date: Apr. 10, 2025
- Vol. 62, Issue 7, 0726001 (2025)
Generation and Optical Field Analysis of Dual-Mode Vortex Beams
Hongyang Wang, Guanxu Chen, Di Wu, Zijing Zhang... and Yuan Zhao|Show fewer author(s)
In recent years, special optical fields, especially vortex beams, have attracted widespread attention for their unique phase, polarization, and amplitude characteristics, which show great potential for applications in optical information transmission, rotational speed measurement, and quantum optics. Using the grating In recent years, special optical fields, especially vortex beams, have attracted widespread attention for their unique phase, polarization, and amplitude characteristics, which show great potential for applications in optical information transmission, rotational speed measurement, and quantum optics. Using the grating diffraction method, firstly, the generation of two types of dual-mode vortex beams, namely vortex beam superposition states and polarization vortex beams are explored in this study. The comparison shows that the structural similarity (SSIM) of the experimental and simulated optical fields of the vortex beam superposition state decreases gradually as the orbital angular momentum (OAM) mode increases. The SSIM of l=±5 is 7.78% lower than that of l=±1. Secondly, the study explores the effect of the center offset between the Gaussian beam and spatial light modulator on distortion of the optical field. As offset increases, the correlation coefficient of the light intensity of different OAM modes gradually decreases. The light intensity correlation coefficient of D=0.5 w is 13.91% lower than that of D=0.1 w (w is waist radius). Finally, by adjusting the parameters of two pure phase gratings with orthogonal modulation directions, we generate polarization vortex beams with adjustable topological charges, polarization orders, and diffraction orders in simulations. The polarization analysis shows that the number of spots detected by the polaroid is twice that of the polarization order. Our research has important theoretical and practical value in expanding the application of vortex beams in optical field regulation..
Laser & Optoelectronics Progress
- Publication Date: Apr. 10, 2025
- Vol. 62, Issue 7, 0726003 (2025)
Reviews
Research Progress of Microcavity Optical Parametric Oscillator Based on Cavity Phase Matching
Yuxin Liu, Kai Zhong, Kai Chen, Jining Li... and Jianquan Yao|Show fewer author(s)
Cavity phase matching (CPM) is a method of compensating for phase mismatch based on reflection phase shifts in resonant microcavities and can ensure efficient optical frequency conversion in nonlinear media within one coherent length. Compared with an optical parametric oscillator (OPO) based on birefringent phase matcCavity phase matching (CPM) is a method of compensating for phase mismatch based on reflection phase shifts in resonant microcavities and can ensure efficient optical frequency conversion in nonlinear media within one coherent length. Compared with an optical parametric oscillator (OPO) based on birefringent phase matching and quasi-phase matching, a microcavity optical parametric oscillator (MOPO) based on CPM is compact, simple, flexible, and applicable to various nonlinear crystals, in addition to exhibiting unique spectral properties. Recently, MOPO theory and technology have been continuously developing. High-efficiency MOPO devices with different operation modes that can generate widely tunable or broadband laser outputs have been developed. Simulation results indicate that this technology can potentially generate monochromatic terahertz waves. Thus, MOPO devices are promising, novel light sources for integrated optics and micro-opto-electro-mechanical systems. This study introduces the basic principle of CPM, analyzes the operating characteristics of an MOPO, summarizes the developments, and outlines the prospects such type of device..
Laser & Optoelectronics Progress
- Publication Date: Apr. 10, 2025
- Vol. 62, Issue 7, 0700008 (2025)
Spectroscopy
Spectroscopic Analysis and Characterization of Dyed and Natural Hongjiaohua Crystals
Qiyun Guan, Duo Xu, Jiaqing Lin, Zhengyu Zhou... and Qi Chen|Show fewer author(s)
To disclose the gemological characteristics of the increasingly numerous dyed Hongjiaohua crystals in the market, natural and dyed Hongjiaohua crystal samples are observed and tested using gemological microscope, ultraviolet-visible spectrophotometer, photoluminescence spectrometer, and Raman spectrometer. The results To disclose the gemological characteristics of the increasingly numerous dyed Hongjiaohua crystals in the market, natural and dyed Hongjiaohua crystal samples are observed and tested using gemological microscope, ultraviolet-visible spectrophotometer, photoluminescence spectrometer, and Raman spectrometer. The results indicate that the inclusion morphological characteristics of natural and dyed Hongjiaohua crystals exhibit significant discrepancies. Inclusions within natural Hongjiaohua crystals exhibit moss, film, nodular, speckled, cloudy, and gauzy forms. While the inclusions within dyed Hongjiaohua crystals may be in the form of colloidal contraction or condensation cracking of organic matter, with pigment colloids often in granular form. Additionally, a difference exists in their ultraviolet-visible diffuse reflectance spectra. Natural samples display an absorption band approximately at 410 nm and a notable deceleration in the slope of the spectrum around 666 nm. Both of these phenomena are ascribed to the transition of Fe3+ within hematite and goethite. However, dyed Hongjiaohua crystals lack this characteristic. The first derivative spectra of the diffuse reflectance spectra for natural samples indicate the presence of hematite, and some samples exhibit the characteristic peak of goethite. A difference of luminescence is also obvious between natural and dyed samples. Natural specimens exhibit no distinct spectral peaks in their photoluminescence spectra, whereas dyed samples present characteristic peaks that are indicative of the presence of dyes. Raman spectroscopy is employed to analyze the surface inclusions of natural Hongjiaohua crystals, thereby confirming that the primary component of these inclusions is hematite..
Laser & Optoelectronics Progress
- Publication Date: Apr. 10, 2025
- Vol. 62, Issue 7, 0730002 (2025)
Improved Attention Mechanism MobileNetV2 Network for SERS Classification of Water Pollution
Xueling Li, Jing Yu, Haiyang Zhang, Lu Dong... and Qi Li|Show fewer author(s)
To address the necessity for rapid identification of pollutants in abrupt water-pollution incidents, a lightweight neural network algorithm suitable for portable devices is proposed. By obtaining surface-enhanced Raman spectroscopy (SERS) data of five common water pollutants and performing preprocessing, a two-dimensioTo address the necessity for rapid identification of pollutants in abrupt water-pollution incidents, a lightweight neural network algorithm suitable for portable devices is proposed. By obtaining surface-enhanced Raman spectroscopy (SERS) data of five common water pollutants and performing preprocessing, a two-dimensional Morlet wavelet transform is applied to separate high- and low-frequency signals, thus enhancing feature representation. To improve the model's feature-extraction capability, a multipooling strategy is introduced, and the efficient channel attention (ECA) mechanism is modified to develop a multipooling attention ECA (MP_ECA) module. This module is integrated with the MobileNetV2 network to construct the MobileNetV2_MP_ECA model for wavelet image classification and recognition. The gradient-weighted class activation mapping (Grad-CAM) technique is utilized to generate heatmaps, which further verifies the effectiveness of wavelet transform in enhancing feature extraction and classification accuracy. Experimental results show that the proposed model achieves a classification accuracy of 97.83%, thus outperforming other attention mechanism models, conventional convolutional neural networks, and common machine-learning methods. Additionally, the model size of proposed model is only 6.11 MB and incurs a floating-point computation of 230.20 MFLOPs, thus rendering it suitable for resource-constrained mobile-device applications. This study provides a novel strategy and approach for efficiently detecting pollutants in real-world abrupt water-pollution scenarios..
Laser & Optoelectronics Progress
- Publication Date: Apr. 10, 2025
- Vol. 62, Issue 7, 0730004 (2025)
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