2024

• Record 301 of
  
  Title:Rapid Determination of Positive–Negative Bacterial Infection Based on Micro-Hyperspectral Technology
  
  Author(s):Du, Jian(1,2); Tao, Chenglong(1,2); Qi, Meijie(1,2); Hu, Bingliang(1,2); Zhang, Zhoufeng(1,2)
  Source: Sensors  Volume: 24  Issue: 2  DOI: 10.3390/s24020507  Published: January 2024  
  Abstract:To meet the demand for rapid bacterial detection in clinical practice, this study proposed a joint determination model based on spectral database matching combined with a deep learning model for the determination of positive–negative bacterial infection in directly smeared urine samples. Based on a dataset of 8124 urine samples, a standard hyperspectral database of common bacteria and impurities was established. This database, combined with an automated single-target extraction, was used to perform spectral matching for single bacterial targets in directly smeared data. To address the multi-scale features and the need for the rapid analysis of directly smeared data, a multi-scale buffered convolutional neural network, MBNet, was introduced, which included three convolutional combination units and four buffer units to extract the spectral features of directly smeared data from different dimensions. The focus was on studying the differences in spectral features between positive and negative bacterial infection, as well as the temporal correlation between positive–negative determination and short-term cultivation. The experimental results demonstrate that the joint determination model achieved an accuracy of 97.29%, a Positive Predictive Value (PPV) of 97.17%, and a Negative Predictive Value (NPV) of 97.60% in the directly smeared urine dataset. This result outperformed the single MBNet model, indicating the effectiveness of the multi-scale buffered architecture for global and large-scale features of directly smeared data, as well as the high sensitivity of spectral database matching for single bacterial targets. The rapid determination solution of the whole process, which combines directly smeared sample preparation, joint determination model, and software analysis integration, can provide a preliminary report of bacterial infection within 10 min, and it is expected to become a powerful supplement to the existing technologies of rapid bacterial detection. © 2024 by the authors.
  Accession Number: 20240515462384
• Record 302 of
  
  Title:Rotating Dual-Retarders to Correct Polarization Measurement Error for Divided-of-Amplitude Polarimeter in Full Field of View
  
  Author(s):Jia, Wentao(1,2); Liu, Kai(1,2); Jiang, Kai(1,2); Shan, Qiusha(1,2); Duan, Jing(1,2); Wu, Linghao(3); Zhou, Liang(1,2)
  Source: SSRN  Volume:   Issue:   DOI: 10.2139/ssrn.4782054  Published: April 2, 2024  
  Abstract:The divided-of-amplitude polarimeter (DoAP) can measure the four Stokes parameters simultaneously, and has the advantages of snapshot and high spatial resolution. However, the residual polarization aberration (PA) of DoPA system will induce the polarization measurement error, and this error is related to the field of view. In this paper, the relationship between the measurement errors of Stokes parameters and the Mueller pupil is derived, and the Mueller pupil of DoPA system is obtained by 3D polarzation ray-tracing matrix. Then, a method of dual-retarders rotation is proposed to correct the Mueller pupil in full field of view. The simulation demonstrates the PA correction can improve the measurement accuracy of DoPA system, and the measurement error of degree of linear polarization is reduced by 11.5%, 38.2% and 11.8% at 0 degree, 10 degrees and 15 degrees field of view, respectively. This research enables high accuracy measurement of polarization signal for polarimeters. © 2024, The Authors. All rights reserved.
  Accession Number: 20240142673
• Record 303 of
  
  Title:Spectral encoder to extract the efficient features of Raman spectra for reliable and precise quantitative analysis
  
  Author(s):Gao, Chi(1,2,3); Fan, Qi(1,2); Zhao, Peng(1,2,3); Sun, Chao(1,2); Dang, Ruochen(1,2,3); Feng, Yutao(1); Hu, Bingliang(1,2); Wang, Quan(1,2)
  Source: Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy  Volume: 312  Issue:   DOI: 10.1016/j.saa.2024.124036  Published: May 5, 2024  
  Abstract:Raman spectroscopy has become a powerful analytical tool highly demanded in many applications such as microorganism sample analysis, food quality control, environmental science, and pharmaceutical analysis, owing to its non-invasiveness, simplicity, rapidity and ease of use. Among them, quantitative research using Raman spectroscopy is a crucial application field of spectral analysis. However, the entire process of quantitative modeling largely relies on the extraction of effective spectral features, particularly for measurements on complex samples or in environments with poor spectral signal quality. In this paper, we propose a method of utilizing a spectral encoder to extract effective spectral features, which can significantly enhance the reliability and precision of quantitative analysis. We built a latent encoded feature regression model; in the process of utilizing the autoencoder for reconstructing the spectrometer output, the latent feature obtained from the intermediate bottleneck layer is extracted. Then, these latent features are fed into a deep regression model for component concentration prediction. Through detailed ablation and comparative experiments, our proposed model demonstrates superior performance to common methods on single-component and multi-component mixture datasets, remarkably improving regression precision while without needing user-selected parameters and eliminating the interference of irrelevant and redundant information. Furthermore, in-depth analysis reveals that latent encoded feature possesses strong nonlinear feature representation capabilities, low computational costs, wide adaptability, and robustness against noise interference. This highlights its effectiveness in spectral regression tasks and indicates its potential in other application fields. Sufficient experimental results show that our proposed method provides a novel and effective feature extraction approach for spectral analysis, which is simple, suitable for various methods, and can meet the measurement needs of different real-world scenarios. © 2024 Elsevier B.V.
  Accession Number: 20240815597901
• Record 304 of
  
  Title:Efficient and high-spatiotemporal-quality terawatt-class mid-infrared optical parametric amplifiers by spatially shaped pumping
  
  Author(s):Liu, Xin(1,2); Li, Jinhui(1,2); Zhen, Qiwen(1,2); Liu, Keyang(1,2); Wang, Yishan(1,2); Zhao, Wei(1,2); Cao, Huabao(1,2); Fu, Yuxi(1,2)
  Source: Journal of the Optical Society of America B: Optical Physics  Volume: 41  Issue: 2  DOI: 10.1364/JOSAB.509609  Published: February 1, 2024  
  Abstract:We propose a method to efficiently generate terawatt (TW)-class mid-infrared (MIR) femtosecond laser pulses with high spatiotemporal quality through optical parametric chirped-pulse amplification (OPCPA). By transforming the pump-beam profile for the OPCPA from Gaussian to flat-top using a designed field mapping optics consisting of two aspherical lenses, we obtain a TW-class femtosecond laser pulse at 2 µm with a conversion efficiency of over 36% according to our simulations. Furthermore, the spatiotemporal coupling effects are greatly suppressed in our method compared to an OPCPA system that is pumped by a widely employed Gaussian profile beam. Our work provides a simple and robust method for developing OPCPA systems with high efficiency and high pulse quality. © 2024 Optica Publishing Group © 2024 Optica Publishing Group (formerly OSA). All rights reserved.
  Accession Number: 20240915655165
• Record 305 of
  
  Title:Design of Optical System for Ultra-Large Range Line-Sweep Spectral Confocal Displacement Sensor
  
  Author(s):Yang, Weiguang(1,2); Du, Jian(1); Qi, Meijie(1); Yan, Jiayue(1,2); Cheng, Mohan(1,2); Zhang, Zhoufeng(1)
  Source: Sensors  Volume: 24  Issue: 3  DOI: 10.3390/s24030723  Published: February 2024  
  Abstract:The spectrum confocal displacement sensor is an innovative type of photoelectric sensor. The non-contact advantages of this method include the capacity to obtain highly accurate measurements without inflicting any harm as well as the ability to determine the object’s surface contour recovery by reconstructing the measurement data. Consequently, it has been widely used in the field of three-dimensional topographic measuring. The spectral confocal displacement sensor consists of a light source, a dispersive objective, and an imaging spectrometer. The scanning mode can be categorized into point scanning and line scanning. Point scanning is inherently present when the scanning efficiency is low, resulting in a slower measurement speed. Further improvements are necessary in the research on the line-scanning type. It is crucial to expand the measurement range of existing studies to overcome the limitations encountered during the detection process. The objective of this study is to overcome the constraints of the existing line-swept spectral confocal displacement sensor’s limited measuring range and lack of theoretical foundation for the entire system. This is accomplished by suggesting an appropriate approach for creating the optical design of the dispersive objective lens in the line-swept spectral confocal displacement sensor. Additionally, prism-grating beam splitting is employed to simulate and analyze the imaging spectrometer’s back end. The combination of a prism and a grating eliminates the spectral line bending that occurs in the imaging spectrometer. The results indicate that a complete optical pathway for the line-scanning spectral confocal displacement sensor has been built, achieving an axial resolution of 0.8 μm, a scanning line length of 24 mm, and a dispersion range of 3.9 mm. This sensor significantly expands the range of measurements and fills a previously unaddressed gap in the field of analyzing the current stage of line-scanning spectral confocal displacement sensors. This is a groundbreaking achievement for both the sensor itself and the field it operates in. The line-scanning spectral confocal displacement sensor’s design addresses a previously unmet need in systematic analysis by successfully obtaining a wide measuring range. This provides systematic theoretical backing for the advancement of the sensor, which has potential applications in the industrial detection of various ranges and complicated objects. © 2024 by the authors.
  Accession Number: 20240715548311
• Record 306 of
  
  Title:Effect of atmospheric environment on the stability of secondary electron emission from magnesium oxide and alumina surfaces
  
  Author(s):Lian, Zhuoxi(1); Zhu, Xiangping(2,3); Wang, Dan(1); Meng, Xiangchen(1); He, Yongning(1)
  Source: Journal of Physics D: Applied Physics  Volume: 57  Issue: 12  DOI: 10.1088/1361-6463/ad15c0  Published: March 22, 2024  
  Abstract:MgO and Al2O3 are two typical ceramics with high secondary electron yield (SEY) and are widely applied in electron multiplier devices as dynode coating. However, dynodes in multipliers are inevitably exposed to various environments, degenerating their SEY performance. To specify the influence of the atmospheric environment on SEY for MgO and Al2O3 ceramics, we conducted environmental stability experiments on MgO and Al2O3 nanofilms. By exposing the nanofilms fabricated by atomic layer deposition to air for certain durations, it was found that although the MgO film possessed high SEY, its SEY decreased significantly as the storage duration increased, specifically, its SEY peak value (δ m) decreased from 5.97 to 3.35 after 180 d. Whereas the SEY of the Al2O3 film changed very little with the storage duration extending, its δ m decreased from 4.01 to 3.70 after 180 d, indicating the Al2O3 film had good SEY environmental stability. To reveal the mechanism of SEY degradation, the modification analysis of surface composition was implemented. It was found that the surface of MgO film underwent degradation besides unavoidable contamination, generating Mg(OH)2 and MgCO3. Whereas, there is no chemical reaction occurred on the Al2O3 surface. Combining the advantages of high SEY of MgO and good environmental stability of Al2O3, several Al2O3/MgO double-layer nanofilms were prepared. The δ m value of 20 nm MgO nanofilms covered by 1 nm Al2O3, decreased from 4.90 to 4.56, with a reduction of only 6.94% after 180 d. The results showed that the Al2O3 film achieved effective protection of the MgO film. The SEY environmental stability of the double-layer structure was significantly improved, and the effect of thickness on SEY was theoretically interpreted. This work makes significant sense for understanding the influence of the environment on the SEY for MgO and Al2O3, which has potential applications in electron multipliers. © 2023 IOP Publishing Ltd.
  Accession Number: 20240115304780
• Record 307 of
  
  Title:Optimization design of cooling system stability of double crystal monochromator
  
  Author(s):Jiang, Bo(1); Chu, Yuanbo(2); Guo, Yifan(2); Dong, Yiming(1)
  Source: Proceedings of SPIE - The International Society for Optical Engineering  Volume: 13080  Issue:   DOI: 10.1117/12.3025729  Published: 2024  
  Abstract:With the development of scientific research, the stability of synchrotron radiation has been paid more attention. The liquid vibration will change the liquid flow state, cause the vibration of the pipe surface, and lead to the crystal jitter. Aiming at the stability requirements of the high-stability monochromator of the partial beam line of SSRF, ANSYS workbench software was used to analyze and optimize the structure, and a cooling pipe system with more stable structure was designed. This paper also analyzes the effect of cooling system vibration on crystal. The test results of the prototype show that the resolution of the device can reach 1 urad and the repetition accuracy is less than 1.071 urad. All the indexes meet the needs of the monochromator. © 2024 SPIE.
  Accession Number: 20241115749947
• Record 308 of
  
  Title:Key assembling and alignment technology of laser communication opto-mechanical system
  
  Author(s):Cao, Mingqiang(1); Lei, Yu(1); Shi, Yuanyuan(1); Ren, Wangtao(1); Liu, Yong(1); Li, Xiaoyan(1); Hou, Xiaohua(1)
  Source: Proceedings of SPIE - The International Society for Optical Engineering  Volume: 13104  Issue:   DOI: 10.1117/12.3024118  Published: 2024  
  Abstract:The optical mechanical system of laser communication has the characteristics of compact structure, highly integration, and multi optical axes integration. The consistency between transmission and reception, divergence angle, and wavefront of the optical telescope of the system are very important indicators. In response to the above difficulties and characteristics, this article conducts research on computer-Aided adjustment, fiber optic coupling, and transceiver consistency testing. Currently, coaxial and off-Axis optical telescope aligning technologies, high-precision fiber optic coupling debugging technology, and turntable linked space optical path transceiver consistency assembling technology have been formed, which can achieve the target requirements of transceiver consistency of 3μrad and system divergence angle of 30μrad. © COPYRIGHT SPIE. Downloading of the abstract is permitted for personal use only.
  Accession Number: 20241816027441
• Record 309 of
  
  Title:Simulation of evaporation ablation dynamics of materials by nanosecond pulse laser of Gaussian beam and flat-top beam
  
  Author(s):Yin, Pei-Qi(1,2); Xu, Bo-Ping(1,2); Liu, Ying-Hua(1,2); Wang, Yi-Shan(1,2); Zhao, Wei(1,2); Tang, Jie(1,2)
  Source: Wuli Xuebao/Acta Physica Sinica  Volume: 73  Issue: 9  DOI: 10.7498/aps.73.20231625  Published: May 5, 2024  
  Abstract:Based on the established two-dimensional asymmetric model of the interaction between a nanosecond pulse laser and metallic aluminum, the effect of beam shaping on the evaporation ablation dynamics during the ablation of metallic aluminum by a nanosecond pulse laser is simulated. The results show that plasma shielding, which has a significant influence on the ablation properties of the target, occurs mainly in the middle phase and late phase of the pulse. Among the three laser profiles, the Gaussian beam has the strongest shielding effect. As the diameter of the reshaped flat-top beam increases, the shielding effect gradually weakens. The two-dimensional spatial distribution of target temperature is relatively different between ablation by a Gaussian beam and that by a flat-top beam. For the Gaussian beam, the center of the target is first heated, and then the temperature spreads in radial direction and axial direction. For the flat-top beam, due to the uniform energy distribution, the target is heated within a certain radial range simultaneously. Beam shaping has a great influence on the evaporation ablation dynamics of the target. For the Gaussian beam, the center of the target is first ablated, followed by the radial ablation. For the flat-top beam, the evaporation time of the target surface is delayed due to the lower energy density after the beam has been shaped. In addition, the target evaporates simultaneously in a certain radial range due to the more uniform distribution of laser energy. For each of the three laser profiles, the evaporation morphology of the target resembles the intensity distribution of the laser beam. The crater produced by the Gaussian beam is deep in the center and shallow on both sides, while it becomes relatively flat by the flat-top beam. © 2024 Institute of Physics, Chinese Academy of Sciences. All rights reserved.
  Accession Number: 20241916068119
• Record 310 of
  
  Title:Random laser emission at 1064 and 1550 nm in a Er/Yb co-doped fiber-based dual-wavelength random fiber laser
  
  Author(s):Li, Zhe(1,2); She, Shengfei(1,2); Li, Gang(1,2); Gao, Qi(1,2); Ju, Pei(1,2); Gao, Wei(1,2); Sun, Chuandong(1); Wang, Yishan(1)
  Source: Optics Express  Volume: 32  Issue: 4  DOI: 10.1364/OE.508025  Published: February 12, 2024  
  Abstract:Dual-wavelength fiber lasers operating with a wide spectral separation are of considerable importance for many applications. In this study, we propose and experimentally explore an all-fiberized dual-wavelength random fiber laser with bi-directional laser output operating at 1064 and 1550 nm, respectively. A specially designed Er/Yb co-doped fiber, by optimizing the concentrations of the co-doped Er, Yb, Al and P, was developed for simultaneously providing Er ions gain and Yb ions gain for RFL. Two spans of single mode passive fibers are employed to providing random feedback for 1064 and 1550 nm random lasing, respectively. The RFL generates 5.35 W at 1064 nm and 6.61 W at 1550 nm random lasers. Two power amplifiers (PA) enhance the seed laser to 50 W at 1064 nm with a 3 dB bandwidth of 0.31 nm and 20 W at 1550 nm with a 3 dB bandwidth of 1.18 nm. Both the short- and long-term time domain stabilities are crucial for practical applications. The output lasers of 1064 and 1550 nm PAs are in the single transverse mode operating with a nearly Gaussian profile. To the best of our knowledge, this is the first demonstration of a dual-wavelength RFL, with a spectral separation as far as about 500 nm in an all-fiber configuration. © 2024 Optica Publishing Group.
  Accession Number: 20240815569595
• Record 311 of
  
  Title:Single-photon ranging lidar based on multi-repetition-rate pulse train correlation and accumulation
  
  Author(s):Kang, Yan(1); Wang, Xiaofang(1,2); Zhang, Tongyi(1,2); Zhao, Wei(1,2)
  Source: Optics Letters  Volume: 49  Issue: 6  DOI: 10.1364/OL.511411  Published: March 15, 2024  
  Abstract:A single-photon lidar based on multi-repetition-rate pulse train correlation and accumulation is proposed, and a ranging experiment is conducted on a 32 m target. By accumulating the correlation ranging results of pulse trains with internal spacings of 80, 100, and 125 ns, the signal-to-noise ratio of the cross correlation function is improved by about three-fold, which enables our method to improve the ranging precisions by more than 20% compared with the single repetition-rate method, and the shorter the acquisition time, the more obvious the advantage will be. Experimental results show that at an acquisition time of 0.01 s, our method can still achieve a ranging precision of 2.59 cm, while the single repetition-rate method can no longer obtain effective ranging results at this time. This method will be of great significance for realizing high-speed, large-scale unambiguous single-photon lidar ranging. © 2024 Optica Publishing Group.
  Accession Number: 20241215777230
• Record 312 of
  
  Title:Inverse design of high efficiency and large bandwidth power splitter for arbitrary power ratio based on deep residual network
  
  Author(s):Wen, Jin(1,2); Wu, Zhengwei(1); Zhang, Hui(1); Wang, Qian(1); Yu, Huimin(1); Zhang, Ying(1); Pan, Yu(1); Liu, Zhanzhi(1)
  Source: Optical and Quantum Electronics  Volume: 56  Issue: 4  DOI: 10.1007/s11082-023-06165-x  Published: April 2024  
  Abstract:In this research, we propose the deep Residual Network to realize the inverse design of a low loss 1 × 3 port power splitter with an area of 2.6 × 2.6 μm2 on a standard silicon-on-insulator platform. Then the area is used as the inverse design region and discretized into 20 × 20 square pixels, where each pixel can be switched between the two random initial states of silicon square with and without holes. Besides, we use the direct binary search algorithm to change the state of the pixels so that the distribution of all pixels in the inverse design region reaches the optimal value of the algorithm. While training the network, inputting spectral transmission response, and using the etched hole vector positions as a label for the inverse design, it achieved an accuracy of 0.9111 and a correlation coefficient greater than 0.88 for all three ports. Finally, we demonstrated 1 × 3 power splitters with 1:2:1, 1:2:1.5, 1:3:1, and 1:3:2 distribution ratios and a more than 90% maximum transmission efficiency with bandwidth from 1450 to 1650 nm while having a low insertion loss of less than 0.45 dB. This research can be found potential applications in the design of photonic devices with high performance and small size. © 2024, The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.
  Accession Number: 20240515480379