2023
2023
-
Record 61 of
Title:Layer by Layer Assembly Cs/Paa for High Sensitivity Detection of Heavy Metal Ions Using Mode Interference Sensor
Author(s):Yan, Minglu(1); Wang, Ruiduo(1,2); Liu, Beibei(1,2); Li, Yangyang(1); Li, Yarong(1); Jiang, Man(1)Source: SSRN Volume: null Issue: null Article Number: null DOI: 10.2139/ssrn.4364067 Published: February 19, 2023Abstract:A low-cost and ease-fabricated mode interference sensor for zinc ion detection is proposed in our work. The sensor is constructed by direct fusion splicing of single-mode fiber (SMF) and no-core fiber (NCF). Experiment and simulation results of the sensor exhibits consistent good response characteristics in the refractive index (RI) range of 1.3324-1.3791. The zinc ion sensitive film was functionalized on the sensor surface by electrostatic self-assembly of chitosan (CS) and polyacrylic acid (PAA), and the experimental results show the optimal detection performance with 12 layers of CS/PAA coated. RI changes in the CS/PAA polymeric film induced by adsorbing zinc ions, which affects the internal energy distribution inside NCF and eventually causes the wavelength shifts. Finally, the high sensitivity of 0.78 nm/ppb and lowest detection limit of 0.01 ppb for zinc ions detection were obtained. Furthermore, the sensing properties of cobalt, sodium and potassium ions were also investigated to evaluate the detection capability for different species metal ions. As a result, the proposed sensor shows well performance on the stability and sensitivity, it has good development prospect in the future water quality environmental monitoring. ? 2023, The Authors. All rights reserved.Accession Number: 20230061243 -
Record 62 of
Title:Lensless coaxial digital holographic imaging based on open-source hardware and deep learning
Author(s):Wang, Junxue(1,2); Lin, Lichen(1,2); Liu, Shiqi(1,2); Ma, Suodong(1,2,3); Shen, Xianmeng(1,2)Source: Proceedings of SPIE - The International Society for Optical Engineering Volume: 12550 Issue: null Article Number: 125501M DOI: 10.1117/12.2666519 Published: 2023Abstract:Lensless coaxial digital holographic imaging (LCDHI) has great advantages of wide-field, high resolution and nondestructive measurement. By removing traditional lenses and utilizing a coaxial optical path, the lens-aberration can be avoided and the imaging process is greatly simplified, which is one of the powerful tools for observing of micro components and biological cells. With the help of an open-source hardware and deep learning technology, a simple and portable experimental device based on the principle of lensless coaxial digital holography is designed and set up in this study. In order to avoid the problems of difficult data-acquisition and time-consuming training caused by supervised learning, a deep convolutional neural network (CNN) based on an auto-encoder is embedded into the Gerchberg-Saxton (GS) iterative process of LCDHI to accomplish phase retrieval. Compared with the traditional GS algorithm, more accurate amplitude and phase results can be reconstructed by the proposed low-cost device and the designed CNN through several experiments. ? 2022 SPIE.Accession Number: 20230813601943 -
Record 63 of
Title:Compact lensless convolution processor for an optoelectronic convolutional neural network
Author(s):Zhang, Zaikun(1,2,3); Kong, Depeng(1); Da, Zhengshang(3); Wang, Ruiduo(1); Wang, Shijie(1); Geng, Yi(4); He, Zhengquan(1)Source: Journal of Physics D: Applied Physics Volume: 56 Issue: 35 Article Number: 355103 DOI: 10.1088/1361-6463/acd06d Published: August 31, 2023Abstract:To our knowledge, optical 4f systems have been widely used as a convolutional layer to perform convolutional computation in free-space optical neural networks (ONNs), which makes ONNs too bulky to be easily applied to miniaturized smart systems. Hence, we propose a compact lensless optoelectronic convolutional neural network (LOE-CNN) architecture in which a single optimized diffractive phase mask acts as an analog convolution processor to perform convolutional operation without a Fourier lens or lenslet array. We demonstrate that this LOE-CNN can be functionally comparable to existing electronic counterparts in classification performance, achieving a classification accuracy of 98.07% and 95% over the Modified National Institute of Standards and Technology dataset in simulation and experiment, respectively, which not only opens new application prospects for free-space ONNs based on a compact single-chip convolution processor, but also facilitates the development of ONN-based smart devices. ? 2023 IOP Publishing Ltd.Accession Number: 20232214173123 -
Record 64 of
Title:Effect of Ce doping on radiation resistance of erbium-doped fiber for space laser communication
Author(s):Wen, Xuan(1); Wang, Gencheng(2,3); Gao, Xin(1); Feng, Zhanzu(1); An, Heng(1); Yin, Hong(1); Wang, Jun(1); She, Shengfei(2,3); Hou, Chaoqi(2,3); Yang, Shengsheng(1)Source: Hongwai yu Jiguang Gongcheng/Infrared and Laser Engineering Volume: 52 Issue: 3 Article Number: 20220871 DOI: 10.3788/IRLA20220871 Published: March 2023Abstract:Objective Space laser communication has the advantages of fast transmission speed, large bandwidth and good confidentiality, and is one of the key development directions of future interplanetary communication. Laser communication requires fast enough transmission rate and high enough transmission power, and erbium-doped fiber amplifier with erbium-doped fiber as the core device is widely used as a signal amplifier in the transmitter and receiver of space laser communication. However, erbium-doped fibers are inevitably affected by the irradiation of space particles in space, which can cause a large number of color-centered defects inside the erbium-doped fiber, resulting in a dramatic decrease in the gain capability and slope efficiency of the device, and then affect the smooth implementation of space laser communication missions. Cerium (Ce) doping is considered as an option to suppress the irradiation loss in optical fibers. Ce can be easily doped into SiO2 glass together with Al, and Ce can suppress the formation of color-centered defects in optical fibers by trapping carriers. Further understanding of the radiation-induced absorption mechanism of Ce doped erbium-doped fibers and enhancing the gain performance of fibers in irradiated environments is essential for the development of space laser communications. Methods Three kinds of erbium-doped optical fibers, namely, high Ce doped(HCe), low Ce doped(LCe) and nonCe doped(NCe) fibers were prepared by chelate vapor deposition. The fibers were irradiated at a cumulative dose of 100 krad and a dose rate of 6.17 rad/s using a 60Co irradiation source at room temperature. The effect of Ce doping on the performance of the erbium-doped fibers under 100 krad gamma irradiation was investigated. The changes of the fiber color center defects were analyzed by absorption coefficient, loss, and Electron Paramagnetic Resonance (EPR) spectra before and after irradiation of the fiber. By testing the fluorescence lifetime and gain coefficient of the fiber, verification of Ce doping enhances the irradiation resistance of erbium-doped fibers. Results and Discussions The fiber loss and absorption spectra were tested and found that the loss values of all three fibers decreased gradually with the increase of wavelength after irradiation, and the loss changes in the range of 900-1600 nm showed the characteristics of short wavelength and high loss, and it was speculated that there might be higher absorption peaks before 900 nm. Through the EPR test, The paramagnetic defects are mainly Al-OHC, Ge(1), Ge(2) and other Ge/Si related defects, and the EPR test verified that the irradiation loss in the operating band of the fiber is mainly due to Al-OHC, and Ce3+/Ce4+ can effectively reduce the number of AlOHC and Ge(1)/Ge(2) related defects number. Thus making the absorption of radiation-induced color-centered defects suppressed. The fluorescence lifetime and gain performance tests showed that the fluorescence lifetime was reduced by 1.099 ms for the NCe and 0.578 ms for the HCe, and the gain of the HCe was 4.15 dB higher than that of the NCe after irradiation. This is due to the fact that Ce doping reduces the AL-OHC defects, decreases the irradiation loss in the working band of the fiber, makes the pump light of the fiber more absorbed by rare-earth ions rather than by color-center defects, and improves the irradiation resistance of the erbium-doped fiber. Conclusions Ce doping can reduce the number of carriers during fiber irradiation and thus suppress the formation of color-centered defects during fiber irradiation. Three types of erbium-doped fibers containing different ratios of Ce ions were selected to study the radiation damage from both macroscopic gain performance and microstructural changes. The loss spectra and absorption spectra before and after irradiation were tested, and it was assumed that the main cause of irradiation loss was the trailing of the color-centered absorption peak before 900 nm in the infrared band. Through the EPR test, it was found that the irradiation loss of fibers with high Ce content is smaller and less color-centered defects appear. The analysis is due to the opposite change induced by the valence state of Ce3+/4+ which tends to keep the balance of the ratio of Ce3+ and Ce4+ ions in the glass, The fluorescence lifetime test before and after fiber irradiation shows that the samples with less change in fluorescence lifetime have stronger irradiation resistance, and Ce doping can suppress the shortening of fluorescence lifetime of erbium-doped fibers, which verifies that Ce doping can effectively improve the irradiation resistance of erbium-doped fibers. The gain performance of the fiber before and after irradiation shows that Ce doping can effectively reduce the number of color center defects in the fiber due to irradiation, which can improve the gain performance of the fiber after irradiation. The results of this study can be used as a reference for the subsequent spatially irradiation-resistant reinforcement technology and space applications of erbium-doped fibers. ? 2023 Chinese Society of Astronautics. All rights reserved.Accession Number: 20232614323400 -
Record 65 of
Title:High Performance Infrared Selective Emissivity Film Tailored for Thermal-Stable Camouflage
Author(s):Kang, Yifan(1,2,3); Yang, Hongtao(1); Wang, Cheng(3); Fan, Qi(3); Lei, Xiaomei(3); Zhang, Haifang(3); Zhu, Guanfang(3); Wang, Chao(4)Source: SSRN Volume: null Issue: null Article Number: null DOI: 10.2139/ssrn.4438400 Published: May 4, 2023Abstract:A polarization-independent broadband infrared selective absorber/emitter (ISAE) based on multilaminar architecture is proposed and demonstrated. The salient features are that it has both much low emissivity in two atmospheric windows (3-5 μm and 8-14 μm) and otherwise high emissivity in two non-atmospheric windows (2.5-3 μm and 5-8 μm), which renders it tailored infrared camouflage performance with thermal stability. Meanwhile, there is sharp narrowband absorption around at 10.6 μm, which allows it to additionally possess desirable laser camouflage performance. The comprehensive dependences of multispectral selective emissivity properties on the structural parameters, the polarization and incident angle of incoming excitation are analyzed and the underlying physical mechanisms are explored. It is found that the selective absorption/emissivity in band 5-8 μm is originated from the fundamental mode plasmonic resonances, while that in 2.5-5 μm is originated from the high-order hybrid mode plasmonic resonances therein. Meanwhile, there does exist a coupled competition effect between the hybrid modes in 2.5-3 μm and in 3-5 μm. All the results construct the basic guideline for designing these kinds of ISAE materials. Furthermore, we reexamine the physical essence of infrared camouflage based on multispectral bands selective emissivity with thermal management and establish an optimized generalized method for evaluating the camouflage performance of ISAE. The proposed ISAE prove to have much better infrared camouflage property throughout the range of 2.5-14 μm than the existing designs reported. The proof-of-principle ISAE is prepared and the selective emission spectrum is characterized, which is in good agreement with the simulations. ? 2023, The Authors. All rights reserved.Accession Number: 20230139345 -
Record 66 of
Title:Optomechanical design analysis and development of space-based visible coded spectrometer based on curved prism dispersion
Author(s):Jia, Xinyin(1); Wang, Feicheng(1); Liu, Jia(1,2,3,4); Zhang, Zhanghui(1); Li, Siyuan(1); Yang, Ying(1); Hu, Bingliang(1); He, Xianqiang(2); Liu, Yupeng(3)Source: Journal of Optics (India) Volume: null Issue: null Article Number: null DOI: 10.1007/s12596-023-01544-9 Published: 2023Abstract:The coded spectrometer, a relatively new instrument, has the advantage of high signal-to-noise ratio, giving it great application potential. We report the optical design of a space-based visible coded spectrometer based on curved prism dispersion (SVCS-CPD) and further explore the design and analysis of its support structure. A static simulation and modal analysis, sinusoidal vibration mechanical analysis, and random vibration mechanical analysis were performed to demonstrate the excellent mechanical and thermal stability of the support structure. To realize rapid assembly and integration of the off-axis optical system, a point source microscope and three-coordinate measuring machines were employed. In addition, tests of optical design parameters and outdoor push-scan imaging were conducted to validate the high imaging performance of the SVCS-CPD. The results showed that the modulation transfer functions of the SVCS-CPD in the central and marginal fields of view were 0.61 at 31.25 line pairs/mm and 0.53 at 31.25 line pairs/mm, respectively. In addition, the spectral smile and spectral keystone were ? 2023, The Author(s), under exclusive licence to The Optical Society of India.Accession Number: 20235215294376 -
Record 67 of
Title:Automated pattern generation for swarm robots using constrained multi-objective genetic programming
Author(s):Fan, Zhun(1,2,3); Wang, Zhaojun(1); Li, Wenji(1); Zhu, Xiaomin(5,6); Hu, Bingliang(7); Zou, An-Min(1); Bao, Weidong(6); Gu, Minqiang(4); Hao, Zhifeng(4); Jin, Yaochu(8)Source: Swarm and Evolutionary Computation Volume: 81 Issue: null Article Number: 101337 DOI: 10.1016/j.swevo.2023.101337 Published: August 2023Abstract:Swarm robotic systems (SRSs), which are widely used in many fields, such as search and rescue, usually comprise a number of robots with relatively simple mechanisms collaborating to accomplish complex tasks. A challenging task for SRSs is to design local interaction rules for self-organization of robots that can generate adaptive patterns to entrap moving targets. Biologically inspired approaches such as gene regulatory network (GRN) models provide a promising solution to this problem. However, the design of GRN models for generating entrapping patterns relies on the expertise of designers. As a result, the design of the GRN models is often a laborious and tedious trial-and-error process. In this study, we propose a modular design automation framework for GRN models that can generate entrapping patterns. The framework employs basic network motifs to construct GRN models automatically without requiring expertise. To this end, a constrained multi-objective genetic programming is utilized to simultaneously optimize the structures and parameters of the GRN models. A multi-criteria decision-making approach is adopted to choose the preferred GRN model for generating the entrapping pattern. Comprehensive simulation results demonstrate that the proposed framework can obtain novel GRN models with simpler structures than those designed by human experts yet better performance in complex and dynamic environments. Proof-of-concept experiments using e-puck robots confirmed the feasibility and effectiveness of the proposed GRN models. ? 2023 Elsevier B.V.Accession Number: 20232314198196 -
Record 68 of
Title:Enhanced Bayesian Factorization With Variant Scale Partitioning for Multivariate Time Series Analysis
Author(s):Tang, Yunbo(1); Chen, Dan(1); Zuo, Yiping(1); Lu, Xiaoqiang(2,3); Ranjan, Rajiv(4); Zomaya, Albert Y.(5); Yao, Quanming(6); Li, Xiaoli(7)Source: IEEE Transactions on Knowledge and Data Engineering Volume: 35 Issue: 4 Article Number: null DOI: 10.1109/TKDE.2021.3128770 Published: April 1, 2023Abstract:Multivariate time series data (Mv-TSD) portray the evolving processes of the system(s) under examination in a 'multi-view' manner. Factorization methods are salient for Mv-TSD analysis with the potentials of structural feature construction correlating various data attributes. However, research challenges remain in the derivation of factors due to highly scattered data distribution of Mv-TSD and intensive interferences/outliers embedded in the source data. The proposed Enhanced Bayesian Factorization approach (Enhanced-BF) addresses the challenges in three phases: (1) variant scale partitioning applies to Mv-TSD according to degree of amplitude and obtains the blocks of variant scales; (2) hierarchical Bayesian model for tensor factorization automatically derives the factors of each block with interferences suppressed; (3) Bayesian unification model merges those block factors to construct the final structural features. Enhanced-BF has been evaluated using a case study of brain data engineering with multivariate electroencephalogram (EEG). Experimental results indicate that the proposed method manifests robustness to the interferences and outperforms the counterparts in terms of operation efficiency and error when factorizing EEG tensor. Besides, Enhanced-BF excels in factorization-based analysis of ongoing autism spectrum disorder (ASD) EEG: 3 times speed-up in factorization and 87.35% accuracy in ASD discrimination. The latent factors ('biomarkers') can distinctly interpret the typical EEG characteristics of ASD subjects. ? 1989-2012 IEEE.Accession Number: 20231113742086 -
Record 69 of
Title:A new Einstein coefficient method for mesopause–lower thermosphere atmosphere temperature retrieval under a non-local thermal equilibrium situation
Author(s):Li, Haotian(1); Feng, Yutao(2); Li, Faquan(3); Wang, Houmao(4); Hu, Xiangrui(1); He, Weiwei(1); Wu, Kuijun(1)Source: Optics Express Volume: 31 Issue: 19 Article Number: null DOI: 10.1364/OE.498765 Published: September 11, 2023Abstract:The mesopause–lower thermosphere (MLT) region is an important spatial region in the Earth’s atmosphere, making it a valuable area to investigate the temperature variations. Kirchhoff’s law fails with the altitude increase due to the non-local thermal equilibrium effect, resulting in an increase in the error of the method to retrieve the atmospheric temperature in the MLT region using the A-band spectral line intensity. In the non-LTE state, the temperature retrieval method based on the Einstein coefficients is proposed to retrieve atmospheric temperature in the 92–140 km height range using the airglow radiation intensity images obtained from the Michelson Interferometer for global high-resolution thermospheric imaging (MIGHTI) measurements. Results show that the temperature deviation of the two-channel combinations does not exceed 15 K in the altitude range of 92–120 km. This deviation increases up to 45 K when the altitude is in the range of 120–140 km due to the influence of the N2 airglow spectrum. The two-channel combinations self-consistency is increased by 85 K compared with the temperature obtained using the spectral line intensity retrieval. Additionally, the comparison of the retrieval results with the spectral line intensity method and the comparison with the atmospheric chemistry experiment Fourier transform spectrometer (ACE-FTS) temperature measurement data shows that the Einstein coefficient method is significantly more rational and accurate than the spectral line intensity method. ? 2023 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement.Accession Number: 20234014824700 -
Record 70 of
Title:Development and prospect of digital twin model for stray light of spaceborne telescope
Author(s):Wu, Yunan(1); Huang, Yi(1); Li, Xuyang(2); Chen, Qinfang(2); Li, Yunfei(3); Chang, Jun(1)Source: Proceedings of SPIE - The International Society for Optical Engineering Volume: 12921 Issue: null Article Number: 129211Q DOI: 10.1117/12.2688626 Published: 2023Abstract:With the continuous deepening of research and development in the field of aerospace, the requirements for aerospace payloads are also increasing. The stray light received by the spaceborne telescope in the space environment will be one of the most important factors affecting its performance. The optical mechanical surface of spaceborne telescope will deviate from the original design due to various objective factors during the whole link process, and the actual optical mechanical surface is not ideal. In order to ensure that it can work normally, it is necessary to simulate and analyze the stray light situation of the whole link. This paper mainly introduces the complex environment and complex characteristics experienced from the ground section to the orbit section, analyzes and summarizes the sources of stray light, and finally proposes a framework for establishing a digital twin model of stray light for spaceborne telescopes. Through data-driven and model-driven methods, finally build a complete set of ground, launch, and in-orbit digital twin models. ? 2023 SPIE.Accession Number: 20234815132578 -
Record 71 of
Title:Simulation of a multichannel vacuum transistor with high cut-off frequency
Author(s):Shen, Zhihua(1); Wang, Xiao(2); Ge, Bin(1); Wu, Shengli(3); Tian, Jinshou(4)Source: Journal of Vacuum Science and Technology B Volume: 41 Issue: 4 Article Number: 043203 DOI: 10.1116/6.0002675 Published: July 1, 2023Abstract:A multichannel vertical vacuum transistor based on the Fowler-Nordheim tunneling emission mechanism was proposed and numerically investigated. The multichannel structure was demonstrated to be effective in enhancing the drain current when compared to the traditional single-channel structure with the same device size. For example, transconductance increased from 0.42 mS of the single-channel structure to 0.86 mS of the four-channel structure. In addition, when the vacuum channel number increases, the size of a single channel decreases correspondingly, leading to a reduction in electric field intensity on the electron emission surface. Thus, the off-state current dramatically reduced by two orders of magnitude reaching10?15 A according to the simulated results. In other words, the ON/OFF drain current ratio of the multichannel structure is significantly enhanced. Furthermore, the simulation results indicate that the cut-off frequency of the multichannel device is 33% higher than that of the traditional single-channel one reaching 0.19 THz. ? 2023 Author(s).Accession Number: 20233014428494 -
Record 72 of
Title:Feature Fusion Semantic Segmentation Model Based on Infrared-RGB Image
Author(s):Qiu, Shi(1,2); Zhang, Ning(2); Cheng, Keyang(3); Song, Yang(4)Source: SSRN Volume: null Issue: null Article Number: null DOI: 10.2139/ssrn.4429183 Published: April 26, 2023Abstract:In order to solve the problem of insufficient segmentation effect of images collected by single source detector, a feature fusion semantic segmentation model is proposed based on infrared and visible shadow images. The complementarity of visible images and infrared images has been given full play to establish detail branch and semantic branch, introduce attention mechanism and suppress the relationship of irrelevant information. Through the analysis of cross entropy loss function and Jaccard loss function, the improved loss function can balance the attributes of features and realize image semantic segmentation. ? 2023, The Authors. All rights reserved.Accession Number: 20230140556