2024

• Record 133 of
  
  Title:Accurate two-step random phase retrieval approach without pre-filtering based on hyper ellipse fitting
  
  Author Full Names:Li, Ziwen(1); Du, Hubing(1); Feng, Leijie(1); Gu, Feifei(2); Li, Yanjie(1); Zhu, Qian(1); Wei, Pengfei(1); Zhang, Gaopeng(3)

  Source Title:Optics Express

  Language:English

  Document Type:Journal article (JA)

  Abstract:In this work, we propose a hyper ellipse fitting-based high-precision random two-frame phase shifting algorithm to improve the accuracy of phase retrieval. This method includes a process of Gram-Schmidt orthonormalization, followed by a hyper ellipse fitting procedure. The Gram-Schmidt orthonormalization algorithm constructs a quadrature fringe pattern relative to the original fringe pattern. These two quadrature fringe patterns are then fed into the hyper ellipse fitting procedure, which reconstructs the phase map and refines the background light to produce the final accurate phase of interest. Due to the hyper ellipse fitting procedure, the demodulation results are significantly improved in many cases. This method allows us to design a two-shot phase reconstruction algorithm without the need for least squares iteration or pre-filtering, effectively mitigating residual background to the greatest extent. It combines the advantages of both the Gram-Schmidt orthonormalization method and the Lissajous ellipse fitting method, making our hyper ellipse fitting approach a simple, flexible, and accurate phase retrieval algorithm. Experiments show that by using the weighted least squares method and adjusting the weights, this method can prioritize data points with more significant information or higher reliability, ensuring more accurate estimation of the ellipse parameters. © 2024 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement.

  Affiliations:(1) School of Mechatronic Engineering, Xi’an Technological University, Shaanxi, Xi’an; 710032, China; (2) Guangdong-Hong Kong-Macao Joint Laboratory of Human-Machine Intelligence Synergy Systems, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen; 518055, China; (3) Xi’an Institute of Optics and Precision Mechanics, CAS, Xi’an; 710119, China

  Publication Year:2024

  Volume:32

  Issue:18

  Start Page:31984-32001

  DOI Link:10.1364/OE.533121

  数据库ID（收录号）:20243616971492
• Record 134 of
  
  Title:Real-Time Registration of Unmanned Aerial Vehicle Hyperspectral Remote Sensing Images Using an Acousto-Optic Tunable Filter Spectrometer
  
  Author Full Names:Liu, Hong(1,2,3,4); Hu, Bingliang(1,3,4); Hou, Xingsong(2); Yu, Tao(1,3,4); Zhang, Zhoufeng(1,3); Liu, Xiao(1,3); Liu, Jiacheng(1,3,4); Wang, Xueji(1,3)

  Source Title:Drones

  Language:English

  Document Type:Journal article (JA)

  Abstract:Differences in field of view may occur during unmanned aerial remote sensing imaging applications with acousto-optic tunable filter (AOTF) spectral imagers using zoom lenses. These differences may stem from image size deformation caused by the zoom lens, image drift caused by AOTF wavelength switching, and drone platform jitter. However, they can be addressed using hyperspectral image registration. This article proposes a new coarse-to-fine remote sensing image registration framework based on feature and optical flow theory, comparing its performance with that of existing registration algorithms using the same dataset. The proposed method increases the structure similarity index by 5.2 times, reduces the root mean square error by 3.1 times, and increases the mutual information by 1.9 times. To meet the real-time processing requirements of the AOTF spectrometer in remote sensing, a development environment using VS2023+CUDA+OPENCV was established to improve the demons registration algorithm. The registration algorithm for the central processing unit+graphics processing unit (CPU+GPU) achieved an acceleration ratio of ~30 times compared to that of a CPU alone. Finally, the real-time registration effect of spectral data during flight was verified. The proposed method demonstrates that AOTF hyperspectral imagers can be used in real-time remote sensing applications on unmanned aerial vehicles. © 2024 by the authors.

  Affiliations:(1) Xi’an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi’an; 710119, China; (2) School of Electronic and Information Engineering, Xi’an Jiao Tong University, Xi’an; 710049, China; (3) Key Laboratory of Spectral Imaging Technology, Chinese Academy of Sciences, Xi’an; 710119, China; (4) University of Chinese Academy of Sciences, Beijing; 100049, China

  Publication Year:2024

  Volume:8

  Issue:7

  Article Number:329

  DOI Link:10.3390/drones8070329

  数据库ID（收录号）:20243116775992
• Record 135 of
  
  Title:Development current status and trends analysis of deep space laser communication (cover paper·invited)
  
  Author Full Names:Gao, Duorui(1,2,3); Sun, Mingyang(1,2,3); He, Mingze(1,2,3); Jia, Shuaiwei(1,2,3); Xie, Zhuang(1,2,3); Yao, Bin(1,2,3); Wang, Wei(1,2)

  Source Title:Hongwai yu Jiguang Gongcheng/Infrared and Laser Engineering

  Language:Chinese

  Document Type:Journal article (JA)

  Abstract:Significance Deep space exploration is the cornerstone of humanity to explore and understand the universe, and it is one of the frontier fields of scientific research. Deep space communication serves as the information bridge that establishes contact between deep space detectors and Earth, acting as a spatial link to ensure the successful completion of deep space exploration missions. The communication system that uses lasers as carrier, characterized by high communication rates, small size, and light weight, has become the main direction for the future development of deep space communication and has also become an international research hotspot in recent years. Progress The article summarizes the characteristics of deep space optical communication technology. Deep space laser communication has the following features: long link distance, significant space loss, extended transmission delay, non-cooperative pointing acquisition and tracking, high relative velocity, large point ahead angle, substantial Doppler frequency shift, and long mission duration. Using examples such as LLCD, DSOC, O2O, LunaNet, OPTEL-D, and DOCS, the article provides a detailed overview of the development trends, latest research progress, and future plans in deep space laser communication technology across the United States, Europe, and China. In the future, deep space laser communication will continue to evolve towards longer communication distances, network integration, terminal miniaturization, integration and type serialization. Key areas of focus include ultra-long-distance PAT, high photon utilization modulation and coding, high-power optical emission, terrestrial large-aperture optical antenna, and ultra-sensitive single-photon reception. The article concludes with a summary and prospects, offering valuable insights for the development of deep space laser communication and interstellar laser communication networks in China. Conclusions and Prospects Both the United States and Europe have been pioneers in deep space laser communication technology research. They have conducted in-orbit technology verification for lunar-to-Earth laser communication and achieved breakthroughs in several key technologies related to deep space laser communication. In contrast, domestic deep space laser communication in China is still in its early stages. Laser communication is an inevitable choice for the future development of deep space communication and is a crucial component of space exploration activities. The moon is the closest celestial body to the earth, carrying out the moon - earth laser communication will provide a more efficient means of data transmission for lunar exploration. Additionally, this effort contributes to building a solid technological foundation for more distant deep space laser communication, marking the first step in China’s research on deep space laser communication technology. Simultaneously, China has initiated planetary exploration projects, and future plans include launching missions to more distant targets such as asteroids and Mars sample return missions. To ensure the successful completion of these long-distance exploration tasks, establishing a matching deep space communication capability is of paramount importance. As laser communication technology continues to evolve, deep space laser communication will become a critical component of the interstellar internet. It will play essential roles in interstellar backbone networks, extension networks, and planetary networks. Furthermore, the development of deep space laser communication complements space optical communication network technologies, mutually reinforcing each other. Ultimately, this progress will lead to the establishment of a near-Earth laser communication network based on ground stations and near-Earth orbit satellites, which will serve as the foundation for an interstellar laser communication network. © 2024 Chinese Society of Astronautics. All rights reserved.

  Affiliations:(1) State Key Laboratory of Transient Optics and Photonics, Xi’an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi’an; 710119, China; (2) Laboratory of Photonics and Network, Xi’an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi’an; 710119, China; (3) University of Chinese Academy of Sciences, Beijing; 100049, China

  Publication Year:2024

  Volume:53

  Issue:7

  Article Number:20240247

  DOI Link:10.3788/IRLA20240247

  数据库ID（收录号）:20243717021107
• Record 136 of
  
  Title:Theoretical derivation and application of empirical Harvey scatter model
  
  Author Full Names:Ma, Zhanpeng(1,2); Wang, Hu(1,2,3); Chen, Qinfang(1,2); Xue, Yaoke(1,2,4,5); Yan, Haoyu(1,2,3); Liu, Jiawen(1,2,3)

  Source Title:Optics Express

  Language:English

  Document Type:Journal article (JA)

  Abstract:Starting from the Rayleigh-Rice perturbation theory, this paper derives the empirical Harvey scatter model and ABg scatter model applied extensively in optical analysis software packages and verifies the shift-invariant behavior of the scattered radiance in direction cosine space. Using data obtained from multi-wavelength laser scatterometer on carbon nanotube black coating and pineblack coating, we establish the polynomial model based on the sine of the scattering angle plus the sine of the specular reflection angle, i.e., sin θs+sin θ0 and the dual-Harvey model based on sin θs-sin θ0 , respectively. The models are in good accordance with the experimental data and further extend the valid range of empirical models. © 2024 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement.

  Affiliations:(1) Xi’an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi’an; 710119, China; (2) Xi’an Space Sensor Optical Technology Engineering Research Center, Xi’an; 710119, China; (3) University of Chinese Academy of Sciences, Beijing; 100049, China; (4) Beihang University, Beijing; 100191, China; (5) Youth Innovation Promotion Association of Chinese Academy of Sciences, Beijing; 100037, China

  Publication Year:2024

  Volume:32

  Issue:6

  Start Page:8986-8998

  DOI Link:10.1364/OE.519414

  数据库ID（收录号）:20241215761907
• Record 137 of
  
  Title:FPM-WSI: Fourier ptychographic whole slide imaging via feature-domain backdiffraction
  
  Author Full Names:Zhang, Shuhe(1,2,3); Wang, Aiye(1,4); Xu, Jinghao(1,4); Feng, Tianci(1,4); Zhou, Jinhua(3); Pan, An(1,4)

  Source Title:arXiv

  Language:English

  Document Type:Preprint (PP)

  Abstract:Fourier ptychographic microscopy (FPM), characterized by high-throughput computational imaging, theoretically provides a cunning solution to the trade-off between spatial resolution and field of view (FOV), which has a promising prospect in the application of digital pathology. However, block reconstruction and then stitching has currently become an unavoidable procedure due to vignetting effects. The stitched image tends to present color inconsistency in different image segments, or even stitching artifacts. Consequently, the advantages of FPM are not as pronounced when compared to the conventional scanning-and-stitching schemes widely employed in whole slide imaging (WSI) systems. This obstacle significantly impedes the profound advancement and practical implementation of FPM, explaining why, despite a decade of development, FPM has not gained widespread recognition in the field of biomedicine. In response, we reported a computational framework based on feature-domain backdiffraction to realize full-FOV, stitching-free FPM reconstruction. Different from conventional algorithms that establish the loss function in the image domain, our method formulates it in the feature domain, where effective information of images is extracted by a feature extractor to bypass the vignetting effect. The feature-domain error between predicted images based on estimation of model parameters and practically captured images is then digitally diffracted back through the optical system for complex amplitude reconstruction and aberration compensation. Through massive simulations and experiments, the method presents effective elimination of vignetting artifacts, and reduces the requirement of precise knowledge of illumination positions. We also found its great potential to recover the data with a lower overlapping rate of spectrum and to realize automatic blind-digital refocusing without a prior defocus distance. Furthermore, to the best of our knowledge, we firstly demonstrated application of FPM on a WSI system, termed FPM-WSI. This platform enables full-color, high-throughput imaging (4.7 mm diameter FOV, 336 nm half-pitch resolution with blue channel illumination) without blocking-and-stitching procedures for a batch of 4 slides. The platform also possesses autofocusing, shifting and regional recognition of slides that are completed by additional automatic mechanical hardware, and the acquisition time for a single slide is less than 4 s. In addition, we provide a user-friendly operation interface to facilitate the workflow, and alternative colorization schemes to choose from. The impact of the reported platform, with advantages of high-quality, high-speed imaging and low cost, will be far-reaching and desired in many fields of biomedical research, as well as in clinical applications. © 2024, CC BY-NC-SA.

  Affiliations:(1) State Key Laboratory of Transient Optics and Photonics, Xi’an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi’an; 710119, China; (2) Maastricht University Medical Center +, Maastricht; 6202 AZ, Netherlands; (3) School of Biomedical Engineering, Anhui Medical University, Hefei; 230032, China; (4) University of Chinese Academy of Sciences, Beijing; 100049, China

  Publication Year:2024

  DOI Link:10.48550/arXiv.2402.18270

  数据库ID（收录号）:20240098566
• Record 138 of
  
  Title:Event-Driven Maximum Correntropy Filter Based on Cauchy Kernel for Spatial Orientation Using Gyros/Star Sensor Integration
  
  Author Full Names:Cui, Kai(1,2,3); Liu, Zhaohui(1,2,3); Han, Junfeng(1,2,3); Ma, Yuke(4); Liu, Peng(1,2,3); Gao, Bingbing(4,5)

  Source Title:Sensors

  Language:English

  Document Type:Journal article (JA)

  Abstract:Gyros/star sensor integration provides a potential method to obtain high-accuracy spatial orientation for turntable structures. However, it is subjected to the problem of accuracy loss when the measurement noises become non-Gaussian due to the complex spatial environment. This paper presents an event-driven maximum correntropy filter based on Cauchy kernel to handle the above problem. In this method, a direct installation mode of gyros/star sensor integration is established and the associated mathematical model is derived to improve the turntable’s control stability. Based on this, a Cauchy kernel-based maximum correntropy filter is developed to curb the influence of non-Gaussian measurement noise for enhancing the gyros/star sensor integration’s robustness. Subsequently, an event-driven mechanism is constructed based on the filter’s innovation information for further reducing the unnecessary computational cost to optimize the real-time performance. The effectiveness of the proposed method has been validated by simulations of the gyros/star sensor integration for spatial orientation. This shows that the proposed filtering methodology not only has strong robustness to deal with the influence of non-Gaussian measurement noise but can also achieve superior real-time spatial applications with a small computational cost, leading to enhanced performance for the turntable’s spatial orientation using gyros/star sensor integration. © 2024 by the authors.

  Affiliations:(1) University of Chinese Academy of Sciences, Beijing; 100049, China; (2) Xi’an Institute of Optics and Precision Mechanics, Xi’an; 710119, China; (3) Key Laboratory of Space Precision Measurement, Chinese Academy of Sciences, Xi’an; 710119, China; (4) School of Automation, Northwestern Polytechnical University, Xi’an; 710072, China; (5) Research & Development Institute, Northwestern Polytechnical University in Shenzhen, Shenzhen; 518063, China

  Publication Year:2024

  Volume:24

  Issue:22

  Article Number:7164

  DOI Link:10.3390/s24227164

  数据库ID（收录号）:20244817452210
• Record 139 of
  
  Title:SPR based dual parameter wide range curling pot shaped photonic crystal fiber sensor
  
  Author Full Names:Guo, Pengxiao(1); Du, Huijing(1); Li, Jianshe(1); Li, Yuxin(1); Li, Shuguang(1); Yin, Zhiyong(1); Wang, Ruiduo(2); Li, Kaifeng(1); Li, Hongwei(1); Li, Xingwei(1)

  Source Title:Physica Scripta

  Language:English

  Document Type:Journal article (JA)

  Abstract:This article proposes a curling pot shaped photonic crystal fiber (PCF) sensor based on surface plasmon resonance (SPR), which utilizes two parallel polished surfaces in the cladding to achieve dual parameter measurements of liquid refractive index (RI) and temperature. The mode characteristics and sensing performance of the designed PCF sensor are studied using the finite element method, and the effects of changes in structural parameters such as pore radius, spacing, and gold film thickness on the resonance spectrum are analyzed. The sensing accuracy of the sensor is insensitive to the change of structural parameters, and it has the characteristics of a wide detection range, high sensitivity, and easy manufacture. When the measured RI is in the range of 1.33∼1.42, the maximum RI sensitivity is 20400 nm RIU−1, and the maximum FOM is 483.3 RIU−1. When the temperature ranges from −10 °C to 100 °C, the maximum sensitivity is 15.4 nm °C−1, and the maximum FOM is 0.43 RIU−1. The tight structure design of the sensor core close to the polishing surface and the anti-spill light design with a uniform arrangement of air holes enhance the SPR effect, which is the essential reason for achieving a wide detection range and high sensitivity. © 2024 IOP Publishing Ltd.

  Affiliations:(1) State Key Laboratory of Metastable Materials Science & Technology, Key Laboratory for Microstructural Material Physics of Hebei Province, School of Science, Yanshan University, Qinhuangdao; 066004, China; (2) State Key Laboratory of Transient Optics and Photonics, Xi’an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences (CAS), Xi’an; 710119, China

  Publication Year:2024

  Volume:99

  Issue:9

  Article Number:095902

  DOI Link:10.1088/1402-4896/ad6694

  数据库ID（收录号）:20243216819469
• Record 140 of
  
  Title:Adaptive decision threshold algorithm based on a sliding window to reduce BER of free-space optical communication systems
  
  Author Full Names:Ying, Ruilei(1,2,3); Zheng, Yunqiang(1,3,4); Wei, Sentao(1); He, Yuanchen(1); Xie, Zhuang(1,3); He, Mingze(1,2,3); Wang, Wei(1,3)

  Source Title:Applied Optics

  Language:English

  Document Type:Journal article (JA)

  Abstract:Free-space optical communication (FSOC) systems face susceptibility to several factors, such as transmission distance, atmospheric turbulence, and alignment errors. These elements contribute to fluctuations in the signal strength reaching the receiver. The resultant signal fluctuations can result in misjudgments and an elevated bit error rate (BER). This paper proposes an adaptive decision threshold algorithm based on a sliding window (ADTSW). By estimating received signal parameters and delimiting the amplitude interval, the algorithm ensures that the decision threshold tracks signal fluctuations, thereby reducing signal misjudgment. The effectiveness of the algorithm is validated through simulations and experimentation. When the signal peak-to-peak value fluctuates, simulation results demonstrate that the proposed algorithm achieves a 1-order-of-magnitude reduction in BER compared to the traditional fixed decision threshold (FDT) method. Under the influence of weak atmospheric turbulence with different scintillation variance, both simulation and experimentation indicate a 1-order-of-magnitude reduction in BER compared to the FDT method. The ADTSW algorithm proves its capability in minimizing misjudgments, thereby effectively reducing BER and improving communication quality. © 2024 Optica Publishing Group © 2024 Optica Publishing Group (formerly OSA). All rights reserved.

  Affiliations:(1) State Key Laboratory of Transient Optics and Photonics, Xi’an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi’an; 710119, China; (2) School of Optoelectronics, University of Chinese Academy of Sciences, Beijing; 100049, China; (3) University of Chinese Academy of Sciences, Beijing; 100049, China; (4) School of Optoelectronic Engineering, Xidian University, Xi’an; 710071, China

  Publication Year:2024

  Volume:63

  Issue:13

  Start Page:3625-3635

  DOI Link:10.1364/AO.519321

  数据库ID（收录号）:20242016084687
• Record 141 of
  
  Title:Ultra-precision intelligent modification strategy of pulsed ion beam for optical components (cover paper·invited)
  
  Author Full Names:Xie, Lingbo(1,2); Shi, Feng(1,2); Tian, Ye(1,2); Gong, Baoqi(1,2); Qiao, Dongyang(1,2); Sun, Guoyan(1,3); Guo, Shuangpeng(1,2); Zhou, Gang(1,2)

  Source Title:Hongwai yu Jiguang Gongcheng/Infrared and Laser Engineering

  Language:Chinese

  Document Type:Journal article (JA)

  Abstract:Objective With the ongoing advancement of optical systems, there has been a growing demand in recent years for precision optical components across various cutting-edge research fields, including EUV lithography lenses, synchrotron radiation X-ray mirrors, and strapdown inertial navigation laser gyro resonators. Ion Beam Polishing (IBP) technology is characterized by its ability to remove complex shapes with excellent stability, absence of edge effects, non-contact non-destructive processing, and high precision. It is commonly employed as the final finishing process for high-precision optical components. While there exist various optimization schemes for the current ion beam shaping machining paths and their velocity distributions, there are still instances where the machine tool's dynamic performance cannot meet the requirements of the optimized machining schemes when processing components with large gradient errors. We introduce a novel Pulsed Ion Beam (PIB) machining technique to overcome the limitations associated with current ion beams in the processing of high-precision optical components. This method not only offers ultra-high removal resolution but also significantly reduces the demands on machine tool dynamics, prevents the formation of extra removal layers, and adeptly achieves precise dwell times at each machining point on the component. Methods This article proposes a new PIB processing method, which adjusts the frequency of the pulse power supply to adjust the period of PIB, and controls the duty cycle to control the duration of the pulse beam current in a single period. It can achieve accurate and controllable material removal in the area that does not require processing by turning off the ion beam current in the non-processing area (Fig.1). Intelligent planning of machining paths using ant colony algorithm (Fig.9). Using ZYGO interferometer to measure the final processing results. Results and Discussions The stability and linearity of PIB have been confirmed (Fig.2), with its removal resolution demonstrated to achieve material removal of 0.33 nm using just 5 pulses. The machining capabilities of traditional IBF and PIB in addressing gradient errors were compared through simulations. The results indicated that when the wavefront gradient of the surface shape error exceeds 0.5 λ/cm, the PIB offers a pronounced advantage in shaping (Fig.6). The implementation of the ant colony algorithm cut ineffective processing paths by 57% (Fig.9). Ultimately, the new processing strategy enabled the acquisition of surfaces with sub-nanometer precision. Following three stages of processing, the RMS error was reduced from 343.438 nm to 0.552 nm (Fig.15). Conclusions This study introduces a new generation of ion beam processing techniques. Compared to traditional IBF methods, the PIB offers superior material removal resolution. By comparing the amounts of material removed with the same sputtering time but varying duty cycles, the PIB system's outstanding stability and linearity in material removal were confirmed. Additionally, five pulses were applied at a frequency of 1 Hz and a 10% duty cycle to sputter hafnium oxide thin films. The comparison of film thicknesses before and after processing confirmed that PIB achieves a sub-nanometer removal resolution of 0.066 nanometers per pulse. Simultaneously, the ACO algorithm was employed to optimize and plan the PIB machining paths, reducing ineffective paths by 57.7%. Ultimately, this processing strategy was used to fabricate an actual monocrystalline silicon mirror, achieving a sub-nanometer precision optical surface of 0.552 nm. This verifies the superior performance of the PIB processing strategy and system in achieving high-precision optical surfaces. It represents a more flexible, accurate, and efficient ion beam processing technique. © 2024 Chinese Society of Astronautics. All rights reserved.

  Affiliations:(1) College of Intelligence Science and Technology, National University of Defense Technology, Changsha; 410003, China; (2) Laboratory of Science and Technology on Integrated Logistics Support, College of Intelligence Science and Technology, National University of Defense Technology, Changsha; 410003, China; (3) Xi’an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi’an; 710119, China

  Publication Year:2024

  Volume:53

  Issue:10

  Article Number:20240283

  DOI Link:10.3788/IRLA20240283

  数据库ID（收录号）:20244317254044
• Record 142 of
  
  Title:FPM-WSI: Fourier ptychographic whole slide imaging via feature-domain backdiffraction
  
  Author Full Names:Zhang, Shuhe(1,2,3); Wang, Aiye(1,4); Xu, Jinghao(1,4); Feng, Tianci(1,4); Zhou, Jinhua(3); Pan, An(1,4)

  Source Title:Optica

  Language:English

  Document Type:Journal article (JA)

  Abstract:Fourier ptychographic microscopy (FPM) theoretically provides a solution to the trade-off between spatial resolution and field of view (FOV), and has promising prospects in digital pathology. However, block reconstruction and then stitching has become an unavoidable procedure for reconstruction of large FOV due to vignetting artifacts. This introduces digital stitching artifacts, as the existing image-domain optimization algorithms are highly sensitive to systematic errors. Such obstacles significantly impede the advancement and practical implementation of FPM, explaining why, despite a decade of development, FPM has not gained widespread recognition in the field of biomedicine. We report a feature-domain FPM (FD-FPM) based on the structure-aware forward model to realize stitching-free, full-FOV reconstruction. The loss function is uniquely formulated in the feature domain of images, which bypasses the troublesome vignetting effect and algorithmic vulnerability via feature-domain backdiffraction. Through massive simulations and experiments, we show that FD-FPM effectively eliminates vignetting artifacts for full-FOV reconstruction, and still achieves impressive reconstructions despite the presence of various systematic errors. We also found it has great potential in recovering the data with a lower spectrum overlapping rate, and in realizing digital refocusing without a prior defocus distance. With FD-FPM, we achieved full-color and high-throughput imaging (4.7 mm diameter FOV, 336 nm resolution in the blue channel) free of blocking-and-stitching procedures on a self-developed Fourier ptychographic microscopy whole slide imaging platform. The reported FD-FPM shows the value of FPM for various experimental circumstances, and offers physical insights useful for the developments of models for other computational imaging techniques. The reported platform demonstrates high-quality, high-speed imaging and low cost, and could find applications in many fields of biomedical research, as well as in clinical applications. © 2024 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement.

  Affiliations:(1) State Key Laboratory of Transient Optics and Photonics, Xi’an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi’an; 710119, China; (2) Maastricht University Medical Center +, Maastricht; 6202 AZ, Netherlands; (3) School of Biomedical Engineering, Anhui Medical University, Hefei; 230032, China; (4) University of Chinese Academy of Sciences, Beijing; 100049, China

  Publication Year:2024

  Volume:11

  Issue:5

  Start Page:634-646

  DOI Link:10.1364/OPTICA.517277

  数据库ID（收录号）:20242116151728
• Record 143 of
  
  Title:ViT Spatio-Temporal Feature Fusion for Aerial Object Tracking
  
  Author Full Names:Guo, Chuangye(1,2,3); Liu, Kang(1,2); Deng, Donghu(1,2); Li, Xuelong(1,2,4)

  Source Title:IEEE Transactions on Circuits and Systems for Video Technology

  Language:English

  Document Type:Journal article (JA)

  Abstract:The object tracking technology for aerial remote sensing images has made significant development, but it is still a very challenging work. The related difficulties of object tracking include the accumulation of long-term tracking errors, similar object interference, partial or full occlusion, scale change, etc, which can lead to object tracking failure. In this paper, an aerial object tracker with ViT Spatio-Temporal Feature Fusion (STFF) for the aerial remote sensing images is proposed, which can achieve accurate tracking of aviation objects. Firstly, we propose a spatial-temporal feature fusion strategy based on the characteristics of object tracking timing. In this strategy, the object information of the previous frames is applied to enhance both the real-time responsiveness of the model and the performance of the tracker. Secondly, the dynamic change information of objects in space and time context is used for spatio-temporal feature information fusion, which can further enhance the appropriate correlation and promote the feature aggregation and information transmission of visual tracking. Finally, a dataset with real and virtual scenarios is collected and constructed to address training data requirements for aviation object tracking. According to our experiments, STFF can achieve accurate tracking of aerial objects and has achieved excellent performance on UAV123, DTB70 and our benchmarks. © 1991-2012 IEEE.

  Affiliations:(1) Northwestern Polytechnical University, School of Artificial Intelligence, OPtics and ElectroNics (IOPEN), Xi'an; 710072, China; (2) Northwestern Polytechnical University, Key Lab. of Intelligent Intrac. and Applications of Ministry of Industry and Information Technology, Xi'an; 710072, China; (3) Avic Xi'an Aeronautics Computing Technique Research Institute, Xi'an; 710068, China; (4) Shanghai Artificial Intelligence Laboratory, Shanghai; 200232, China

  Publication Year:2024

  Volume:34

  Issue:8

  Start Page:6749-6761

  DOI Link:10.1109/TCSVT.2023.3326695

  数据库ID（收录号）:20234615059313
• Record 144 of
  
  Title:Snapshot compressive imaging at 855 million frames per second for aluminium planar wire array Z-pinch
  
  Author Full Names:Yao, Zhiming(1); Ji, Chao(2); Sheng, Liang(1); Song, Yan(1); Liu, Zhen(1); Han, Changcai(1); Zhou, Haoyu(1,3); Duan, Baojun(1); Li, Yang(1); Hei, Dongwei(1); Tian, Jinshou(2); Xue, Yanhua(2)

  Source Title:Optics Express

  Language:English

  Document Type:Journal article (JA)

  Abstract:This paper present a novel, integrated compressed ultrafast photography system for comprehensive measurement of the aluminium planar wire array Z-Pinch evolution process. The system incorporates a large array streak camera and embedded encoding to improve the signal-to-noise ratio. Based on the "QiangGuang-I" pulsed power facility, we recorded the complete continuous 2D implosion process of planar wire array Z-Pinch for the first time. Our results contribute valuable understanding of imploding plasma instabilities and offer direction for the optimization of Z-Pinch facilities. © 2024 Optica Publishing Group.

  Affiliations:(1) National Key Laboratory of Intense Pulsed Radiation Simulation and Effect, Northwest Institute of Nuclear Technology, Xi’an; 710024, China; (2) Key Laboratory of Ultra-Fast Photoelectric Diagnostics Technology, Xi’an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi’an; 710119, China; (3) Department of Engineering Physics, Tsinghua University, Beijing; 100085, China

  Publication Year:2024

  Volume:32

  Issue:4

  Start Page:6567-6574

  DOI Link:10.1364/OE.512450

  数据库ID（收录号）:20240815569617