2024

• Record 61 of
  
  Title:Efficient single-cycle mid-infrared femtosecond laser pulse generation by spectrally temporally cascaded optical parametric amplification with pump energy recycling
  
  Author(s):Yuan, Hao; Huang, Pei; Feng, Tongyu; Ma, Yahui; Wang, Xianglin; Cao, Huabao; Wang, Yishan; Zhao, Wei; Fu, Yuxi
  Source: OPTICS LETTERS  Volume: 49  Issue: 9  DOI: 10.1364/OL.519729  Published: 2024  
  Abstract:We proposed spectrally temporally cascaded optical parametric amplification (STOPA) using pump energy recycling to simultaneously increase spectral bandwidth and conversion efficiency in optical parametric amplification (OPA). Using BiB 3 O 6 and KTiOAsO 4 nonlinear crystals, near -single -cycle mid -infrared (MIR) pulses with maximum energy conversion efficiencies exceeding 25% were obtained in simulations. We successfully demonstrated sub -two-cycle, CEP -stable pulse generation at 1.8 mu m using a four -step STOPA system in the experiment. This method provides a solution to solve the limitations of the gain bandwidth of nonlinear crystals and the low conversion efficiency in broadband OPA systems, which is helpful for intense attosecond pulse generation and strong laser field physics studies. (c) 2024 Optica Publishing Group
  Accession Number:
  ISSN: 0146-9592
  eISSN: 1539-4794
• Record 62 of
  
  Title:Tracking control of a flexible-link manipulator based on an improved barrier function adaptive sliding mode
  
  Author(s):Jing, Feng; Ma, Caiwen; Wang, Fan; Xie, Meilin; Feng, Xubin; Fan, Xiao; Wang, Xuan; Liu, Peng
  Source: ASIAN JOURNAL OF CONTROL  Volume:   Issue:   DOI: 10.1002/asjc.3383  Published: 2024  
  Abstract:In this paper, a novel controller designed for robust tracking control of a flexible-link manipulator operating in the presence of parameter uncertainties and external disturbances within the joint space is introduced. The proposed controller employs an adaptive sliding mode control approach, incorporating an improved barrier function, to ensure that trajectory errors remain within predefined performance bounds. This design enhances the tracking performance without overestimating control-switching gains. Additionally, a fixed-time adaptive sliding mode control, featuring a rapid nonsingular terminal sliding mode variable, is introduced to expedite the convergence rate of the system state during the initial stages. The efficacy of the proposed control scheme is established through the Lyapunov method, demonstrating finite-time convergence of the trajectory error to a specified neighborhood of zero. Experimental validation on a flexible-link system supports the effectiveness and advantages of the proposed control strategy, as evidenced via comparisons with two existing adaptive control schemes.
  Accession Number:
  ISSN: 1561-8625
  eISSN: 1934-6093
• Record 63 of
  
  Title:Content-illumination coupling guided low-light image enhancement network
  
  Author(s):Zhao, Ruini; Xie, Meilin; Feng, Xubin; Su, Xiuqin; Zhang, Huiming; Yang, Wei
  Source: SCIENTIFIC REPORTS  Volume: 14  Issue: 1  DOI: 10.1038/s41598-024-58965-0  Published: 2024  
  Abstract:Current low-light enhancement algorithms fail to suppress noise when enhancing brightness, and may introduces structural distortion and color distortion caused by halos or artifacts. This paper proposes a content-illumination coupling guided low-light image enhancement network (CICGNet), it develops a truss topology based on Retinex as backbone to decompose low-light image component in an end-to-end way. The preservation of content features and the enhancement of illumination features are carried out along with depth and width direction of the truss topology. Each submodule uses the same resolution input and output to avoid the introduction of noise. Illumination component prevents misestimation of global and local illumination by using pre- and post-activation features at different depth levels, this way could avoid possible halos and artifacts. The network progressively enhances the illumination component and maintains the content component stage-by-stage. The proposed algorithm demonstrates better performance compared with advanced attention-based low-light enhancement algorithms and state-of-the-art image restoration algorithms. We also perform extensive ablation studies and demonstrate the impact of low-light enhancement algorithm on the downstream task of computer vision. Code is available at: https://github.com/Ruini94/CICGNet.
  Accession Number: 8456
  ISSN: 2045-2322
  eISSN:
• Record 64 of
  
  Title:Design and fabrication of a tellurite hollow-core anti-resonant fiber for mid-infrared
  
  Author(s):Zhu, Jun; Feng, Shaohua; Liu, Chengzhen; Cai, Liyang; Xu, Yantao; Xiao, Xusheng; Guo, Haitao
  Source: OPTICS EXPRESS  Volume: 32  Issue: 8  DOI: 10.1364/OE.519034  Published: 2024  
  Abstract:The hollow core anti -resonant fibers (HC-ARFs) based on soft glass are in high demand for 3-6 pm laser delivery. A HC-ARF based on tellurite glass with 6 touching capillaries as cladding was designed and fabricated for the first time, to the best of our knowledge. A relatively low loss of 3.75 dB/m at 4.45 pm was realized in it. The effects of capillary number, core diameter, wall thickness of capillary, and material absorption loss on the loss of the HC-ARF were analyzed by the numerically simulation. The output beam quality was measured and the influence of bending on the fiber loss was discussed. The results of numerical simulation suggested that the theoretical loss of the prepared fiber can be reduced to 0.1 dB/m, indicating that tellurite HC-ARFs have great potential for mid -infrared laser applications. (c) 2024 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement
  Accession Number:
  ISSN: 1094-4087
  eISSN:
• Record 65 of
  
  Title:Circularly polarized RABBITT applied to a Rabi-cycling atom
  
  Author(s):Liao, Yijie; Olofsson, Edvin; Dahlstrom, Jan Marcus; Pi, Liang-Wen; Zhou, Yueming; Lu, Peixiang
  Source: PHYSICAL REVIEW A  Volume: 109  Issue: 4  DOI: 10.1103/PhysRevA.109.043104  Published: 2024  
  Abstract:We utilize the reconstruction of attosecond beating by interference of two-photon transitions (RABBITT) technique to study the phase of a Rabi-cycling atom using circularly polarized extreme ultraviolet and infrared fields, where the infrared field induces Rabi oscillations between the 2s and 2p states of lithium. Autler-Townes splittings are observed in sidebands of the photoelectron spectra and the relative phases of outgoing electron wave packets are retrieved from the azimuthal angle. In this RABBITT scheme, more ionization pathways beyond the usual two-photon pathways are required. Our results show that the polar-angle-integrated and polar-angleresolved RABBITT phases have different behaviors when the extreme ultraviolet and infrared fields have coand counter-rotating circular polarizations, which are traced back to the different ionization channels according to the selection rules in these two cases and their competition relying on the propensity rule in laser-assisted photoionization.
  Accession Number: 43104
  ISSN: 2469-9926
  eISSN: 2469-9934
• Record 66 of
  
  Title:Optimization of multilayer capacitive charge division anode for MCP imaging detectors
  
  Author(s):Yang, Kai; Bai, Yonglin; Wang, Bo; Cao, Weiwei; Zhu, Bingli; Bai, Xiaohong; Zheng, Jinkun; Zhang, Shengdan; Wang, Chao; Chen, Zhen; Yang, Yang
  Source: NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT  Volume: 1063  Issue:   DOI: 10.1016/j.nima.2024.169285  Published: 2024  
  Abstract:A three-dimensional numerical model developed based on the finite element method to simulate the positionreconstruction performance of multilayer capacitive anodes is presented. The charge collection efficiency and position nonlinearity are calculated for different electrode layers, patterns, and sizes, as well as the distance between the bottom microchannel plate (MCP) and induction layer. The position nonlinearity exhibits an approximately linear relationship with the electrode size and the distance between the bottom MCP and induction layer. By increasing the electrode area in the perimeter region and designing 2.2 mm square electrodes in the central region, a position nonlinearity of 3.36% with a distance of 5 mm between the bottom MCP and induction layer is achieved. The imaging performance of the six multilayer capacitive anodes is evaluated using a custom-designed detector prototype, and the experimental results validate the simulation results. The comprehensively optimized capacitive anode shows an imaging nonlinearity of 0.91% in the experiment.
  Accession Number: 169285
  ISSN: 0168-9002
  eISSN: 1872-9576
• Record 67 of
  
  Title:Environmentally stable all-fiber femtosecond laser for industrial application based on a SESAM mode-locked ytterbium-doped laser
  
  Author(s):Cao, Xue; Li, Feng; Song, Dongdong; Wang, Yishan; Li, Qianglong; Zhao, Hualong; Zhao, Wei; Wen, Wenlong; Si, Jinhai
  Source: MICROWAVE AND OPTICAL TECHNOLOGY LETTERS  Volume: 66  Issue: 4  DOI: 10.1002/mop.34119  Published: 2024  
  Abstract:We demonstrate an environmentally stable femtosecond laser for industrial application based on all polarization-maintaining Yb-doped laser and experimentally explore the effect of the net cavity dispersion (NCD) on output characteristics. The oscillator emits pulses with 5.1 ps and a 23 nm spectral bandwidth, then the pulse is compressed to 88 fs. The instabilities over 120 h gives 0.32% relative root mean square noise, indicating high stability of the pulse laser. With effective regulation of NCD, we obtained the maximum spectral bandwidth of 27 nm. Such broadband oscillator with compact all-fiber configurations provide extremely high stability should be very attractive for long-term industrial application.
  Accession Number: e34119
  ISSN: 0895-2477
  eISSN: 1098-2760
• Record 68 of
  
  Title:Multi-Dimensional Fusion of Spectral and Polarimetric Images Followed by Pseudo-Color Algorithm Integration and Mapping in HSI Space
  
  Author(s):Guo, Fengqi; Zhu, Jingping; Huang, Liqing; Li, Feng; Zhang, Ning; Deng, Jinxin; Li, Haoxiang; Zhang, Xiangzhe; Zhao, Yuanchen; Jiang, Huilin; Hou, Xun
  Source: REMOTE SENSING  Volume: 16  Issue: 7  DOI: 10.3390/rs16071119  Published: 2024  
  Abstract:Spectral-polarization imaging technology plays a crucial role in remote sensing detection, enhancing target identification and tracking capabilities by capturing both spectral and polarization information reflected from object surfaces. However, the acquisition of multi-dimensional data often leads to extensive datasets that necessitate comprehensive analysis, thereby impeding the convenience and efficiency of remote sensing detection. To address this challenge, we propose a fusion algorithm based on spectral-polarization characteristics, incorporating principal component analysis (PCA) and energy weighting. This algorithm effectively consolidates multi-dimensional features within the scene into a single image, enhancing object details and enriching edge features. The robustness and universality of our proposed algorithm are demonstrated through experimentally obtained datasets and verified with publicly available datasets. Additionally, to meet the requirements of remote sensing tracking, we meticulously designed a pseudo-color mapping scheme consistent with human vision. This scheme maps polarization degree to color saturation, polarization angle to hue, and the fused image to intensity, resulting in a visual display aligned with human visual perception. We also discuss the application of this technique in processing data generated by the Channel-modulated static birefringent Fourier transform imaging spectropolarimeter (CSBFTIS). Experimental results demonstrate a significant enhancement in the information entropy and average gradient of the fused image compared to the optimal image before fusion, achieving maximum increases of 88% and 94%, respectively. This provides a solid foundation for target recognition and tracking in airborne remote sensing detection.
  Accession Number: 1119
  ISSN:
  eISSN: 2072-4292
• Record 69 of
  
  Title:Memory deficit in patients with cerebral small vessel disease: evidence from eye tracking technology
  
  Author(s):Huang, Kailing; Zhao, Tingting; Sun, Weifeng; Feng, Li; Wang, Quan; Feng, Jie
  Source: CEREBRAL CORTEX  Volume: 34  Issue: 4  DOI: 10.1093/cercor/bhae138  Published: 2024  
  Abstract:Cerebral small vessel disease is the one of the most prevalent causes of vascular cognitive impairment. We aimed to find objective and process-based indicators related to memory function to assist in the detection of memory impairment in patients with cerebral small vessel disease. Thirty-nine cerebral small vessel disease patients and 22 healthy controls were invited to complete neurological examinations, neuropsychological assessments, and eye tracking tasks. Eye tracking indicators were recorded and analyzed in combination with imaging features. The cerebral small vessel disease patients scored lower on traditional memory task and performed worse on eye tracking memory task performance compared to the healthy controls. The cerebral small vessel disease patients exhibited longer visit duration and more visit count within areas of interest and targets and decreased percentage value of total visit duration on target images to total visit duration on areas of interest during decoding stage among all levels. Our results demonstrated the cerebral small vessel disease patients performed worse in memory scale and eye tracking memory task, potentially due to their heightened attentional allocation to nontarget images during the retrieval stage. The eye tracking memory task could provide process-based indicators to be a beneficial complement to memory assessment and new insights into mechanism of memory impairment in cerebral small vessel disease patients.
  Accession Number: bhae138
  ISSN: 1047-3211
  eISSN: 1460-2199
• Record 70 of
  
  Title:Optimizing centroiding using indexed table lookup: Application to crossed-strip readout
  
  Author(s):La, An-Peng; Zhang, Wen-Wen; Yang, Yang; Zheng, Jin-Kun; Bai, Yong-Lin; Song, Yu-Chao; Duan, Jin-Yao; Zhang, Yanxin; Wang, Fang; Zhao, Hua
  Source: AIP ADVANCES  Volume: 14  Issue: 4  DOI: 10.1063/5.0186696  Published: 2024  
  Abstract:This paper introduces a hybrid readout system for a cross-strip position-sensitive anode detector that combines a lookup table and weighted averaging. The lookup table approach is used to identify event channels and select appropriate weights based on the corresponding index code for calculating the centroid of the electron cloud. This effectively enhances the readout system's processing speed while preserving the high-resolution advantage of the cross-strip position-sensitive anode. Simulations were performed to evaluate the performance of the system. Experimental results demonstrate that this readout method achieves an event processing speed exceeding 10 MHz while maintaining a resolution of 17.96 lp/mm.
  Accession Number: 45103
  ISSN:
  eISSN: 2158-3226
• Record 71 of
  
  Title:Sub-50 fs pulses generation from an all-fiber monolithic gain-managed nonlinear amplifier with CFBG-based pre-compressor
  
  Author(s):Li, Qianglong; Li, Feng; Liu, Hongjun; Zhao, Wei; Cao, Xue; Zhao, Hualong; Wang, Yishan; Wen, Wenlong; Si, Jinhai
  Source: LASER PHYSICS LETTERS  Volume: 21  Issue: 4  DOI: 10.1088/1612-202X/ad291f  Published: 2024  
  Abstract:We demonstrate an all-fiber monolithic laser source from a gain-managed nonlinear (GMN) fiber amplifier with a CFBG-based pre-compressor that generates high-contrast pulses with a repetition rate of 80 MHz, average power of 1.6 W, and pulse duration of sub-50 fs. The compressed pulse quality can be optimized by tuning the parameters of the seed pulses injected into the GMN amplifier by controlling the pump power of the fiber pre-amplifier. This compact and cost-effective laser system is a simplified design of the GMN amplification-based femtosecond fiber laser systems. With alignment-free characteristics in the amplifiers and clean compressed pulses, it is easy to assemble and use in applications such as multi-photon microscopy.
  Accession Number: 45101
  ISSN: 1612-2011
  eISSN: 1612-202X
• Record 72 of
  
  Title:Temperature Measurement Method for Small Target Medium-Wave Infrared Spectral Radiation Based on Distance Correction
  
  Author(s):Li Wen-kai; Zhou Liang; Liu Zhao-hui; Cui Kai; Liu Kai; Li Zhi-guo; Xie Mei-lin
  Source: SPECTROSCOPY AND SPECTRAL ANALYSIS  Volume: 44  Issue: 4  DOI: 10.3964/j.issn.1000-0593(2024)04-1158-07  Published: 2024  
  Abstract:For long-distance space targets moving at high speeds, temperature is one of the important parameters to characterize their working state and performance. Accurately obtaining the temperature of the target has an important reference value for judging its motion state and predicting its situation development. At present, the commonly used processing method of surface target or point target is no longer applicable to the measurement of the radiation characteristics of small targets. At the same time, spectral detection increases the distinguishable information of the target in the wavelength dimension, which can accurately obtain the distribution of the target energy with wavelength, providing a possibility for the inversion of the target temperature, and has great application potential. The slitless spectrometer can reduce the requirements for tracking and stabilization accuracy of space targets, has the characteristics of simple structure, high frame rate and fast response speed, and has high application value in astronomical observation and spacecraft observation. In this paper, we analyzed the spectral calibration model of target infrared radiation characteristic measurement and determined the main parameters in the linear response model of infrared detector pixels. In order to reduce the influence of imaging distance on temperature measurement accuracy, we proposed a target temperature inversion model based on distance correction. The improved temperature measurement accuracy meets the accuracy requirements in practical engineering applications and greatly affects infrared radiation spectrum temperature measurement. Certain guiding significance.
  Accession Number:
  ISSN: 1000-0593
  eISSN: