2023

• Record 37 of
  
  Title:RGB-guided hyperspectral image super-resolution with deep progressive learning
  
  Author(s):Zhang, Tao(1); Fu, Ying(1); Huang, Liwei(2); Li, Siyuan(3); You, Shaodi(4); Yan, Chenggang(5)
  Source: CAAI Transactions on Intelligence Technology  Volume: null  Issue: null  Article Number: null  DOI: 10.1049/cit2.12256  Published: 2023  
  Abstract:Due to hardware limitations, existing hyperspectral (HS) camera often suffer from low spatial/temporal resolution. Recently, it has been prevalent to super-resolve a low resolution (LR) HS image into a high resolution (HR) HS image with a HR RGB (or multispectral) image guidance. Previous approaches for this guided super-resolution task often model the intrinsic characteristic of the desired HR HS image using hand-crafted priors. Recently, researchers pay more attention to deep learning methods with direct supervised or unsupervised learning, which exploit deep prior only from training dataset or testing data. In this article, an efficient convolutional neural network-based method is presented to progressively super-resolve HS image with RGB image guidance. Specifically, a progressive HS image super-resolution network is proposed, which progressively super-resolve the LR HS image with pixel shuffled HR RGB image guidance. Then, the super-resolution network is progressively trained with supervised pre-training and unsupervised adaption, where supervised pre-training learns the general prior on training data and unsupervised adaptation generalises the general prior to specific prior for variant testing scenes. The proposed method can effectively exploit prior from training dataset and testing HS and RGB images with spectral-spatial constraint. It has a good generalisation capability, especially for blind HS image super-resolution. Comprehensive experimental results show that the proposed deep progressive learning method outperforms the existing state-of-the-art methods for HS image super-resolution in non-blind and blind cases. © 2023 The Authors. CAAI Transactions on Intelligence Technology published by John Wiley & Sons Ltd on behalf of The Institution of Engineering and Technology and Chongqing University of Technology.
  Accession Number: 20233014425959
• Record 38 of
  
  Title:Near-noiseless and small-footprint phase sensitive optical parametric amplifier using AlGaAs-on-insulator waveguides
  
  Author(s):Xie, Zhuang(1,2,3); Jia, Shuaiwei(1,2,3); Shao, Wen(1,2,3); Han, Xiaotian(1,2,3); Su, Yulong(4); Meng, Jiacheng(1,3); Gao, Duorui(1,3); Wang, Wei(1,3); Xie, Xiaoping(1,2,3)
  Source: Applied Optics  Volume: 62  Issue: 27  Article Number: null  DOI: 10.1364/AO.501279  Published: September 20, 2023  
  Abstract:Phase sensitive amplifiers (PSAs) based on optical parametric amplification feature near noiseless amplification, which is of considerable benefit for improving the performance of optical communication systems. Currently, the majority of research on PSAs is carried out on the basis of highly nonlinear fibers or periodically poled lithium niobite waveguides, with the impediments of being susceptible to environmental interference and requiring complex temperature control systems to maintain quasi-phase matching conditions, respectively. Here, a near-noiseless and small-footprint PSA based on dispersion-engineered AlGaAs-on-insulator (AlGaAsOI) waveguides is proposed and demonstrated theoretically. The phase-dependent gain and the phase-to-phase transfer function of the PSA are calculated to analyze its characteristics. Furthermore, we investigate in detail the effects of linear loss, nonlinear coefficient, and pump power on the PSA gain and noise figure (NF) in AlGaAsOI waveguides. The results show that a PSA based on an AlGaAsOI waveguide is feasible with a maximum phase sensitive gain of 33 dB, achieving an NF of less than 1 dB over a gain bandwidth of 245 nm with a gain of >15 dB, which completely covers the S + C + L band. This investigation is worthwhile for noiseless PSAs on photonic integrated chips, which are promising for low-noise optical amplification, multifunctional photonic integrated chips, quantum communication, and spectroscopy, and as a reference for low-noise PSAs depending on the third-order nonlinearity, χ(3), of the waveguide material. © 2023 Optica Publishing Group.
  Accession Number: 20233914802712
• Record 39 of
  
  Title:Free-space transmission of picosecond-level, high-speed optical pulse streams in the 3 µm band
  
  Author(s):Su, Yulong(1); Tian, Wenlong(1); Yu, Yang(2); Meng, Jiacheng(3,4); Zheng, Yunqiang(1,3,4); Jia, Shuaiwei(3,4); Xie, Zhuang(3,4); Wang, Yishan(3,4); Zhu, Jiangfeng(1); Wang, Wei(3,4)
  Source: Optics Express  Volume: 31  Issue: 17  Article Number: null  DOI: 10.1364/OE.497175  Published: August 14, 2023  
  Abstract:The utilization of mid-infrared (mid-IR) light spanning the 3-5 µm range presents notable merits over the 1.5 µm band when operating in adverse atmospheric conditions. Consequently, it emerges as a promising prospect for serving as optical carriers in free-space communication (FSO) through atmospheric channels. However, due to the insufficient performance level of devices in the mid-IR band, the capability of mid-IR communication is hindered in terms of transmission capacity and signal format. In this study, we conduct experimental investigations on the transmission of time-domain multiplexed ultra-short optical pulse streams, with a pulse width of 1.8 ps and a data rate of up to 40 Gbps at 3.6 µm, based on the difference frequency generation (DFG) effect. The mid-IR transmitter realizes an effective wavelength conversion of optical time division multiplexing (OTDM) signals from 1.5 µm to 3.6 µm, and the obtained power of the 40 Gbps mid-IR OTDM signal at the optimum temperature of 54.8 °C is 7.4 dBm. The mid-IR receiver successfully achieves the regeneration of the 40 Gbps 1.5 µm OTDM signal, and the corresponding regenerated power at the optimum temperature of 51.5 °C is -30.56 dBm. Detailed results pertaining to the demodulation of regeneration 1.5 µm OTDM signal have been acquired, encompassing parameters such as pulse waveform diagram, bit error rate (BER), and Q factor. The estimated power penalty of the 40 Gbps mid-IR OTDM transmission is 2.4 dB at a BER of 1E-6, compared with the back-to-back (BTB) transmission. Moreover, it is feasible by using chirped PPLN crystals with wider bandwidth to increase the data rate to the order of one hundred gigabits. © 2023 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement.
  Accession Number: 20233614674344
• Record 40 of
  
  Title:Study on surface and subsurface qualities in rotary ultrasonic vibration-assisted peripheral grinding of ULE
  
  Author(s):Guoyan, Sun(1,2,3); Feng, Shi(2); Yongsheng, Yao(1); Jiaoteng, Ding(1); Yongjie, Wang(1)
  Source: Proceedings of SPIE - The International Society for Optical Engineering  Volume: 12507  Issue: null  Article Number: 1250715  DOI: 10.1117/12.2655438  Published: 2023  
  Abstract:UlE, as a kind of ultra-low thermal expansion glass, has been widely applied in large-aperture optical mirrors and space telescopes. However, hard-brittle material feature of ULE brings certain difficulty for machining. In this paper, rotary ultrasonic vibration-assisted peripheral grinding (RUPG), combining rotary ultrasonic vibration（UV）and conventional grinding (CG) is proposed, and grinding process and quality characteristic are investigated in terms of surface morphology, grinding force, surface roughness, subsurface damage depth, and subsurface morphology. A serious of comparative experiments for between RUPG and CG were conducted. The results show that rotary UV in RUPG can markedly decrease the grinding force with a factor of 46.78%. The change rule of grinding force with the varying of grinding parameters in RUPG is consistent with that in CG, i.e., grinding force increases as the increasing of grinding depth and feed rate, while it decreases with the growth of spindle speed. Grinding surface marks were found to be obviously weakened by UV and surface consistency was accordingly improved. Besides, measurement results of surface roughness also real that UV plays a positive role in diminishing surface roughness by almost 23.01%, and reducing the subsurface damage depth by a factor of 17.19%. © 2023 SPIE. All rights reserved.
  Accession Number: 20230613538009
• Record 41 of
  
  Title:Effect of UV Scattering on Detection Limit of SO2 Cameras
  
  Author(s):Wu, Kuijun(1); Zhang, Zihao(1); Guo, Jianjun(1); Hu, Xiangrui(1); Li, Juan(2); Li, Faquan(3); He, Weiwei(1)
  Source: Remote Sensing  Volume: 15  Issue: 3  Article Number: 705  DOI: 10.3390/rs15030705  Published: February 2023  
  Abstract:SO2 ultraviolet (UV) camera technology has been successfully applied to the accurate imaging detection of pollutant gas concentration; however, the actual detection ability of this technology has not been intensively studied, especially the detection accuracy and limit under the influence of the light dilution effect. Here, we theoretically and experimentally investigate the UV scattering on SO2 concentration inversion. The radiation transfer model of the light dilution effect is reconstructed, and the concept of the optimized detection limit is discussed. An outfield experiment is conducted on a ship exhaust, and the results are compared with the theoretical calculations, which indicates that the detection limit of the SO2 UV camera is 15 ppm·m at close range and increases to 25 ppm·m when the detection distance is 3.5 km. This study proves that the detection limit of the SO2 UV camera deteriorates with the decreasing atmospheric visibility, the lengthening detection distance, and the increasing aerosol content within the plume. In addition, the hardware indicators of the camera systems also play a key role in the detection limit, and taking reasonable image processing can significantly release the instruments’ performance and extend the applicability of the SO2 UV camera. © 2023 by the authors.
  Accession Number: 20230713592888
• Record 42 of
  
  Title:On-orbit demonstration of inter-satellite free-space optical stable communication enabled by integrated optical amplification of HPA and LNA
  
  Author(s):Bai, Zhaofeng(1,2,3); Meng, Jiacheng(1,3); Su, Yulong(4); Zheng, Yunqiang(1,4); Chang, Zhiyuan(1); Wei, Sentao(1); Gao, Duorui(1,3); Nie, Wenchao(1); Meng, Xiangsheng(1,3); Han, Junfeng(1); Xue, Bin(1); Zhang, Chunmin(2); Wang, Wei(1); Xie, Xiaoping(1,3)
  Source: Applied Optics  Volume: 62  Issue: 23  Article Number: null  DOI: 10.1364/AO.484983  Published: August 10, 2023  
  Abstract:Satellite free-space optical (FSO) communication is very promising in improving the bandwidth and capacity of space information networks in the future. However, the inter-satellite transmission distance of over 1000 km leads to unstable optical beam pointing, acquisition, and tracking and then generates optical power jitter by a large margin before detection–demodulation. Therefore, it is difficult to realize high-stability and long-time FSO communication between satellites due to the generated bit error rate (BER) by jitter. In this paper, we report an autonomously self-designed and high-integration laser communication payload (LCP) and on-orbit-demonstrated inter-satellite 145 min, zero-BER FSO stable communication with a line rate of 2.8 Gbps. Moreover, based on the inter-satellite laser communication link, a video phone was clearly implemented for more than 10 min, and authentic user data transmitted 459,149 packets, achieving results of zero-packet loss. Summarily, this on-orbit experiment demonstrated an excellent performance of the LCP owing to the distinctive design of integrating a high-power amplifier and low-noise amplifier optical amplification function. Our space mission was successfully completed, and the on-orbit demonstration results may offer a significant reference for the field of satellite laser communication and space information networks. © 2023 Optica Publishing Group.
  Accession Number: 20232614321971
• Record 43 of
  
  Title:Investigation of Critical Determinants in Photoacoustic Imaging Systems: An Analysis of Key Factors Impacting Performance
  
  Author(s):Qiao, Wenlong(1,2,3,4); Jiang, Le(1); Zhou, Liang(1,3); Liu, Zhaohui(1,3); Lv, Yuanyuan(1,2,3); Chen, Peiquan(1,2,3); Zhang, Haiyang(1,2,3)
  Source: SSRN  Volume: null  Issue: null  Article Number: null  DOI: 10.2139/ssrn.4416294  Published: April 11, 2023  
  Abstract:Photoacoustic imaging is an emerging non-invasive, non-ionizing, and safe method for imaging biological tissues. The design and development of clinically available photoacoustic imaging devices will help advance this technology, however, today there is no reliable reference for the selection of major instrument parameters in photoacoustic imaging devices, and most of them are based on the experience of previous researchers. In this work, we present a simulation model for photoacoustic imaging, our simulation model is based on the finite element analysis method and considers the four physical processes of photoacoustic effect, including light energy absorption distribution, transient temperature rise, thermal expansion and acoustic pressure generation and transmission in biological tissues. Our results provide insights into the impact of laser pulse widths, laser wavelengths and absorber sizes on photoacoustic signals. We observe that the pulse width affects the sound pressure value, center frequency, and spectral range of the photoacoustic signals, and that the laser wavelength only affects the amplitude of the time-domain photoacoustic signals. Our findings also demonstrate that multispectral photoacoustic imaging can identify the same absorbers based on the acoustic spectrum. Furthermore, our analysis of the time-frequency domain characteristics of photoacoustic signals generated by different absorber sizes indicates that larger absorber sizes result in lower center frequencies of the signals. These results provide a solid foundation for the design and optimization of photoacoustic imaging systems. © 2023, The Authors. All rights reserved.
  Accession Number: 20230117612
• Record 44 of
  
  Title:Investigation of the interference phenomenon between ultrashort pulses based on an all-fiber laser
  
  Author(s):Duan, Lina(1); Wang, Yishan(2); Guo, Huinan(3); Wang, Hushan(2); Fan, Wei(1); Li, Yan(1); Hao, Minru(1); Liu, Pandi(1)
  Source: Laser Physics  Volume: 33  Issue: 4  Article Number: 045101  DOI: 10.1088/1555-6611/acbb78  Published: April 1, 2023  
  Abstract:We experimentally report on the interference phenomenon between ultrashort pulses in fiber media. When the pulse interval goes further to a certain small scale, the interference effects can arise. As a result, the spectrum appears to be a modulation phenomenon. Different from the phenomenon of bound-state pulses in a fiber laser cavity, the relationship between the modulation period of the spectrum and the pulse interval in the time domain seems to go against the interference principle. At the same time, the time interval between the two pulses is far greater than the time difference caused by the optical path difference. We are very confused. It seems that when two pulses overlap by a certain proportion in time, they will push each other apart to increase the time interval. Moreover, when the pulse interval becomes smaller and the two pulses are overlapped in time, the corresponding autocorrelation trace exhibits only one peak with regular modulation instead of the conventional three peaks with equal spacing, which looks very strange and is hard to explain. Limited by our technical tools, we could not illustrate the physical causes, but there is no doubt that it will be very meaningful to research what happens. Our observations have found some novel optical phenomena in experiment, which may provide some reference for further exploration of interference phenomena between ultrashort pulses. © 2023 Astro Ltd.
  Accession Number: 20231013659587
• Record 45 of
  
  Title:Fourier Ptychography Reconstruction Based on Reweighted Amplitude Flow With Regularization by Denoising and Deep Decoder
  
  Author(s):Li, Baopeng(1,2,3); Ma, Caiwen(4); Ersoy, Okan K.(5); Pan, Zhibin(2); Wen, Wansha(4); Sun, Zhonghan(4); Gao, Wei(4)
  Source: IEEE Photonics Journal  Volume: 15  Issue: 1  Article Number: 8500110  DOI: 10.1109/JPHOT.2022.3230422  Published: February 1, 2023  
  Abstract:Fourier ptychography (FP) is a computational imaging technique with the advantage that it can obtain large field-of-view (FOV) and high-resolution (HR) imaging. We propose an algorithm for Fourier ptychography based on reweighted amplitude flow (RAF) with regularization by denoising (RED) and deep decoder (DD), which is an untrained deep generative model. The proposed method includes two loops, using reweighted amplitude flow with regularization by denoising as an inner loop for phase retrieval and deep decoder for further denoising as an outer loop in the Fourier ptychography recovery system. The proposed method does not need any training dataset, just adds a little computer time during the image recovery process. The proposed method has no bias due to training images, which is different from other deep learning methods. The experimental results show that the proposed method can improve the reconstruction quality in both PSNR and SSIM. © 2009-2012 IEEE.
  Accession Number: 20230313393249
• Record 46 of
  
  Title:Vector solitonic pulses excitation in microresonators via free carrier effects
  
  Author(s):Mulong, L.I.U.(1); Dang, Yaai(1); Huang, Huimin(2); Zhizhou, L.U.(3); Sen, M.E.I.(1); Yanan, C.A.I.(1); Zhou, Wenquan(1); Zhao, And W.E.I.(4)
  Source: Optics Express  Volume: 31  Issue: 20  Article Number: null  DOI: 10.1364/OE.498671  Published: September 25, 2023  
  Abstract:We numerically investigate the excitation of vector solitonic pulse with orthogonally polarized components via free-carrier effects in microresonators with normal group velocity dispersion (GVD). The dynamics of single, dual and oscillated vector pulses are unveiled under turn-key excitation with a single frequency-fixed CW laser source. Parameter spaces associated with detuning, polarization angle, interval between the pumped orthogonal resonances and pump amplitude have been revealed. Different vector pulse states can also be observed exploiting the traditional pump scanning scheme. Simultaneous and independent excitation regimes are identified due to varying interval of the orthogonal pump modes. The nonlinear coupling between two modes contributes to the distortion of the vector pulses’ profile. The free-carrier effects and the pump polarization angle provide additional degrees of freedom for efficiently controlling the properties of the vector solitonic microcombs. Moreover, the crucial thermal dynamics in microcavities is discussed and weak thermal effects are found to be favorable for delayed vector pulse formation. These findings reveal complex excitation mechanism of solitonic structures and could provide novel routes for microcomb generation. © 2023 OSA - The Optical Society. All rights reserved.
  Accession Number: 20234214923610
• Record 47 of
  
  Title:Blood Glucose Concentration Estimation by Raman Spectroscopy based on Particle Swarm Optimized SVR
  
  Author(s):Jing, Haonan(1,2,3); Fan, Qi(1,3); Gao, Chi(1,2,3); Li, Yiru(1,2,3); Fan, Bozhao(1,2); Hu, Bingliang(1,3); Feng, Yutao(1); Wang, Quan(1,3)
  Source: Proceedings of SPIE - The International Society for Optical Engineering  Volume: 12562  Issue: null  Article Number: 1256209  DOI: 10.1117/12.2651838  Published: 2023  
  Abstract:Blood glucose level has important significance for medical diagnosis. Blood glucose measurement in traditional methods requires collecting blood samples several times a day, which causes discomfort, environmental pollution and so on. As a "fingerprint" spectrum for molecular recognition, Raman spectroscopy has attracted attention in blood glucose measurement. However, blood glucose level is low and spectral signal of glucose is easy to be influenced by noise and other components. To improve accuracy of blood glucose concentration estimation by Raman spectroscopy, we carried out the Raman blood glucose measurement in vitro, the interferograms of blood samples in different glucose concentrations were measured by the self-developed Spatial Heterodyne Raman Spectrometer (SHRS), and converted the interferograms to one-dimensional spectroscopic data using Fourier transform. In order to get data with higher quality, we used wavelet decomposition to remove the noise and sparse representation to remove the signal baseline. Then, selected the spectroscopy at 500-2500 cm-1 as input, and the corresponding blood glucose concentration value as label, use particle swarm optimization-support vector regression (PSO-SVR) algorithm to construct the blood glucose concentration estimation model. The results show that the R2 of test set is 0.8041 and the RMSE is 1.8580. And the accuracy of blood glucose concentration estimation was evaluated by the Clark Error Grid. The model based on PSO-SVR can achieve accurate estimation of blood glucose concentration. This method has important research significance and application potential for blood glucose measurement. © 2023 SPIE.
  Accession Number: 20230613559811
• Record 48 of
  
  Title:Simultaneous detection of multi-component greenhouse gases based on an all-fibered near-infrared single-channel frequency-division multiplexing wavelength-modulated laser heterodyne radiometer
  
  Author(s):Sun, Chunyan(1,2,3); He, Xinyu(1); Zhang, Ke(4); Bai, Jin(1); Liu, Xin-shuang(1)
  Source: Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy  Volume: 293  Issue: null  Article Number: 122434  DOI: 10.1016/j.saa.2023.122434  Published: May 15, 2023  
  Abstract:The performance of an all fibered near-infrared (NIR) single-channel frequency-division multiplexing wavelength-modulated laser heterodyne radiometer (FDM WM-LHR) is demonstrated in ground-based solar occultation mode. The system modulates the laser through the high-frequency signal output by the lock-in amplifier to replace the traditional chopper modulation, making it more stable and compact. Moreover, personal computers are used to simultaneously control the operating current of two distributed feedback (DFB) lasers through a general purpose interface bus-universal serial bus (GPIB-USB), thereby controlling the central wavelength of the laser at 1602.88 and 1653.727 nm, which serve as the absorption lines for the local oscillator detection of the two main greenhouse gases: CO2 and CH4. Firstly, the performance of traditional laser heterodyne radiometer (LHR) and the wavelength-modulated laser heterodyne radiometer (WM-LHR) are compared. The results reveal that both the radiometers have an optimized 2f signal when the modulation amplitude m = 2.2. In the actual measurement, 0.25 V and 0.21 V are selected as the modulation amplitude of the laser for the detection of CH4 and CO2. Under the same experimental parameters, at 1602.88 nm, the signal-to-noise ratio (SNR) for the 2f signal of CO2 in the WM-LHR system is 500.24, while that for the direct absorption signal (DAS) of CO2 in the traditional LHR system is 337.94. At 1653.727 nm, the SNR for the 2f signal in the WM-LHR system and the DAS of CH4 in the traditional LHR system are 512.04 and 389.58, respectively. Obviously, the SNR for the WM-LHR system is greatly improved. Finally, the application of frequency-division multiplexing (FDM) technology in the WM-LHR system is discussed. The modulation frequency of the two lasers should be appropriately selected to avoid interference between the signals. Overall, the results show that the FDM WM-LHR system can not only detect multiple gases simultaneously but also reduce the implementation cost of the ground-based radiometer. In addition, this study provides useful insights on planetary atmosphere exploration. © 2023
  Accession Number: 20230713587297