2024

• Record 97 of
  
  Title:Infrared imaging of magnetic octupole domains in non-collinear antiferromagnets
  
  Author(s):Wang, Peng; Xia, Wei; Shen, Jinhui; Chen, Yulong; Peng, Wenzhi; Zhang, Jiachen; Pan, Haolin; Yu, Xuhao; Liu, Zheng; Gao, Yang; Niu, Qian; Xu, Zhian; Yang, Hongtao; Guo, Yanfeng; Hou, Dazhi
  Source: NATIONAL SCIENCE REVIEW  Volume: 11  Issue: 6  DOI: 10.1093/nsr/nwad308  Published: 2024  
  Abstract:Magnetic structure plays a pivotal role in the functionality of antiferromagnets (AFMs), which not only can be employed to encode digital data but also yields novel phenomena. Despite its growing significance, visualizing the antiferromagnetic domain structure remains a challenge, particularly for non-collinear AFMs. Currently, the observation of magnetic domains in non-collinear antiferromagnetic materials is feasible only in Mn3Sn, underscoring the limitations of existing techniques that necessitate distinct methods for in-plane and out-of-plane magnetic domain imaging. In this study, we present a versatile method for imaging the antiferromagnetic domain structure in a series of non-collinear antiferromagnetic materials by utilizing the anomalous Ettingshausen effect (AEE), which resolves both the magnetic octupole moments parallel and perpendicular to the sample surface. Temperature modulation due to AEE originating from different magnetic domains is measured by lock-in thermography, revealing distinct behaviors of octupole domains in different antiferromagnets. This work delivers an efficient technique for the visualization of magnetic domains in non-collinear AFMs, which enables comprehensive study of the magnetization process at the microscopic level and paves the way for potential advancements in applications. Infrared imaging employing the anomalous Ettingshausen effect unveils magnetic domain structures in non-collinear antiferromagnets, unlocking new possibilities in spintronics and memory device development.
  Accession Number:
  ISSN: 2095-5138
  eISSN: 2053-714X
• Record 98 of
  
  Title:Flexible fiberbotic laser scalpels: Material and fabrication challenges
  
  Author(s):Zou, Yuqi; Ren, Zhihe; Xiang, Yuanzhuo; Liu, Chao; Gao, Anzhu; Huang, Shaoping; Yang, Lvyun; Hou, Chong; Guo, Haitao; Yang, Guang-Zhong; Tao, Guangming
  Source: MATTER  Volume: 7  Issue: 3  DOI: 10.1016/j.matt.2024.01.007  Published: 2024  
  Abstract:Rapidly developed fiber lasers have shown great potential in interventional urology, inspiring the use of advanced laser delivery to meet the demand for manipulation in other complex surgical scenarios. While medical robots are enhancing precision in the field of minimally invasive surgery, laser ablation has been demonstrated as a promising candidate compared to traditional mechanical cutting tools in interventions. Nevertheless, based on their ablation mechanisms, the advantages of lasers are still not fully leveraged. In this Perspective, we outline how fiber -shaped robots combined with laser scalpels are primed to emerge as the next generation of medical robots to achieve minimally invasive surgery. We review the mechanisms involved, analyze their applications, and discuss several prospects for future applications.
  Accession Number:
  ISSN: 2590-2393
  eISSN: 2590-2385
• Record 99 of
  
  Title:Scalable parallel ultrafast optical random bit generation based on a single chaotic microcomb
  
  Author(s):Li, Pu; Li, Qizhi; Tang, Wenye; Wang, Weiqiang; Zhang, Wenfu; Little, Brent E.; Chu, Sai Tek; Shore, K. Alan; Qin, Yuwen; Wang, Yuncai
  Source: LIGHT-SCIENCE & APPLICATIONS  Volume: 13  Issue: 1  DOI: 10.1038/s41377-024-01411-7  Published: 2024  
  Abstract:Random bit generators are critical for information security, cryptography, stochastic modeling, and simulations. Speed and scalability are key challenges faced by current physical random bit generation. Herein, we propose a massively parallel scheme for ultrafast random bit generation towards rates of order 100 terabit per second based on a single micro-ring resonator. A modulation-instability-driven chaotic comb in a micro-ring resonator enables the simultaneous generation of hundreds of independent and unbiased random bit streams. A proof-of-concept experiment demonstrates that using our method, random bit streams beyond 2 terabit per second can be successfully generated with only 7 comb lines. This bit rate can be easily enhanced by further increasing the number of comb lines used. Our approach provides a chip-scale solution to random bit generation for secure communication and high-performance computation, and offers superhigh speed and large scalability.
  Accession Number: 66
  ISSN: 2095-5545
  eISSN: 2047-7538
• Record 100 of
  
  Title:Extending UWOC System Applications through Photon Transmission Dynamics Study in Harbor Waters
  
  Author(s):Chang, Chang; Han, Xiaotian; Li, Guangying; Li, Peng; Nie, Wenchao; Liao, Peixuan; Li, Cong; Wang, Wei; Xie, Xiaoping
  Source: APPLIED SCIENCES-BASEL  Volume: 14  Issue: 6  DOI: 10.3390/app14062493  Published: 2024  
  Abstract:Underwater wireless optical communication (UWOC) in harbor waters can facilitate real-time monitoring underwater instruments for environmental monitoring, underwater inspection, and maintenance tasks. This study delves into the complex dynamics of UWOC in four distinct harbor waters. The research employs Monte Carlo method incorporated with Fournier-Forand scattering phase function for simulating photon transmission. Key parameters such as the Transmitted full divergence angle, received aperture, and Field of View (FOV) are meticulously evaluated for their impact on power loss and time delay spread. Notably, the normalized power loss and time delay spread are found to be more significantly affected by communication distance than water quality, and the traditional Beer-Lambert law is ineffective in harbor water. The power loss of Harbor II, III, and IV are found to be 14.00 dB, 31.59 dB, and 41.59 dB lower than that of Harbor I, and the time delay spread of Harbor II, III, and IV is 30.56%, 9.67%, and 0.49% times that of the Harbor I under certain conditions. In addition, increasing the received aperture and FOV, particularly over longer distance, make little contribution to reduce the power loss and mitigate the time delay spread. Based on the fixed transmitted full divergence angle, the most applicable received FOV range is 1-3.2 rad, and the most ideal received aperture is 0.15-0.4 m. Under these conditions, the variation in normalized power loss is less than 2 dB. Additionally, the time delay spread remains within the same order of magnitude with the attenuation length (AL) held constant. These conclusions hold substantial technical relevance for the engineering design of UWOC systems in harbor waters.
  Accession Number: 2493
  ISSN:
  eISSN: 2076-3417
• Record 101 of
  
  Title:Saturable absorption properties and ultrafast photonics applications of HfS3
  
  Author(s):Li, Lu; Xue, Ze; Pang, Lihui; Xiao, Xusheng; Yang, Huiran; Zhang, Jinniu; Zhang, Yarning; Zhao, Qiyi; Liu, Wenjun
  Source: OPTICS LETTERS  Volume: 49  Issue: 5  DOI: 10.1364/OL.513573  Published: 2024  
  Abstract:In this Letter, we focus on investigating the ultrafast photonics applications of two -layer HfS3 nanosheets. We prepared two -layer HfS3 nanosheets and carried out experiments to study their nonlinear saturable absorption properties. The results showed that the two -layer HfS3-based saturable absorber exhibited a modulation depth of 16.8%. Additionally, we conducted theoretical calculations using first principles to estimate the structural and electronic band properties of the two -layer HfS3 material. Furthermore, we utilized the two -layer HfS3 materials as SAs in an erbiumdoped fiber cavity to generate mode -locked laser pulses. We measured a repetition frequency of 8.74 MHz, a pulse duration of 540 fs, and a signal-to-noise ratio of 77 dB. Overall, our findings demonstrate that the two -layer HfS3 material can serve as a reliable saturable absorber, possessing properties comparable to currently used two-dimensional materials. This expands the application fields of HfS3 materials and highlights their potential for advanced optoelectronic devices. (c) 2024 Optica Publishing Group
  Accession Number:
  ISSN: 0146-9592
  eISSN: 1539-4794
• Record 102 of
  
  Title:Computational Imaging: The Next Revolution for Biophotonics and Biomedicine
  
  Author(s):Pan, An; Yao, Baoli; Zuo, Chao; Liu, Fei; Yang, Jiamiao; Cao, Liangcai
  Source: CELLS  Volume: 13  Issue: 5  DOI: 10.3390/cells13050433  Published: 2024  
  Abstract:
  Accession Number: 433
  ISSN:
  eISSN: 2073-4409
• Record 103 of
  
  Title:High linear sensitivity humidity and temperature sensing based on chiral long-period fiber grating
  
  Author(s):Ren, Kaili; Hu, Jiayue; Jia, Aochi; Xi, Jiawei; Ren, Yuchong; Yan, Xuewen; Li, Jinze; Dong, Jun; Liu, Jihong
  Source: OPTICAL ENGINEERING  Volume: 63  Issue: 3  DOI: 10.1117/1.OE.63.3.036103  Published: 2024  
  Abstract:A highly sensitive, reversible, and linear sensor, exhibiting excellent stability in response to temperature and humidity, has been successfully proposed and demonstrated for the first time. This sensor is achieved by wrapping a polyvinyl alcohol/graphene nanofiber film onto a chiral long-period fiber grating (CLPG), which is fabricated by periodically twisting single mode fiber. In the experiment, the CLPG sensor demonstrates a temperature sensitivity of 74 pm/degrees C, which is approximately twice as high as that of conventional fiber grating sensors. Note that, by wrapping the graphene nanofiber film on CLPG, the temperature sensitivity of the sensor is up to 115.23 pm/degrees C in the range of 30 degrees C to 75 degrees C. In addition, CLPG using for humidity sensing is first demonstrated. The humidity sensitivity measures -9.92 pm/%RH with linearity of 0.995 during a change from 40%RH to 80%RH. In comparison to other humidity sensors, the sensitivity of the CLPG is comparable, whereas its sensing linearity stands out notably above the rest. The results show that CLPG has the characteristics of simple fabrication, easy combination with materials, stable performance, and high sensitivity and holds significant development potential in optical fiber sensing application fields. (c) 2024 Society of Photo-Optical Instrumentation Engineers (SPIE)
  Accession Number: 36103
  ISSN: 0091-3286
  eISSN: 1560-2303
• Record 104 of
  
  Title:Hybrid Grid Pattern Star Identification Algorithm Based on Multi-Calibration Star Verification
  
  Author(s):Shen, Chao; Ma, Caiwen; Gao, Wei; Wang, Yuanbo
  Source: SENSORS  Volume: 24  Issue: 5  DOI: 10.3390/s24051661  Published: 2024  
  Abstract:In order to solve the star identification problem in the lost space mode for scientific cameras with small fields of view and higher instruction magnitudes, this paper proposes a star identification algorithm based on a hybrid grid pattern. The application of a hybrid pattern generated by multi-calibration stars in the initial matching enables the position distribution features of neighboring stars around the main star to be more comprehensively described and avoids the interference of position noise and magnitude noise as much as possible. Moreover, calibration star filtering is adopted to eliminate incorrect candidates and pick the true matched navigation star from candidate stars in the initial match. Then, the reference star image is utilized to efficiently verify and determine the final identification results of the algorithm via the nearest principle. The performance of the proposed algorithm in simulation experiments shows that, when the position noise is 2 pixels, the identification rate of the algorithm is 96.43%, which is higher than that of the optimized grid algorithm by 2.21% and the grid algorithm by 4.05%; when the magnitude noise is 0.3 mag, the star identification rate of the algorithm is 96.45%, which is superior to the optimized grid algorithm by 2.03% and to the grid algorithm by 3.82%. In addition, in the actual star image test, star magnitude values of <= 12 mag can be successfully identified using the proposed algorithm.
  Accession Number: 1661
  ISSN:
  eISSN: 1424-8220
• Record 105 of
  
  Title:Adaptive Dual Aggregation Network with Normalizing Flows for Low-Light Image Enhancement
  
  Author(s):Wang, Hua; Cao, Jianzhong; Huang, Jijiang
  Source: ENTROPY  Volume: 26  Issue: 3  DOI: 10.3390/e26030184  Published: 2024  
  Abstract:Low-light image enhancement (LLIE) aims to improve the visual quality of images taken under complex low-light conditions. Recent works focus on carefully designing Retinex-based methods or end-to-end networks based on deep learning for LLIE. However, these works usually utilize pixel-level error functions to optimize models and have difficulty effectively modeling the real visual errors between the enhanced images and the normally exposed images. In this paper, we propose an adaptive dual aggregation network with normalizing flows (ADANF) for LLIE. First, an adaptive dual aggregation encoder is built to fully explore the global properties and local details of the low-light images for extracting illumination-robust features. Next, a reversible normalizing flow decoder is utilized to model real visual errors between enhanced and normally exposed images by mapping images into underlying data distributions. Finally, to further improve the quality of the enhanced images, a gated multi-scale information transmitting module is leveraged to introduce the multi-scale information from the adaptive dual aggregation encoder into the normalizing flow decoder. Extensive experiments on paired and unpaired datasets have verified the effectiveness of the proposed ADANF.
  Accession Number: 184
  ISSN:
  eISSN: 1099-4300
• Record 106 of
  
  Title:A Lightweight Remote Sensing Aircraft Object Detection Network Based on Improved YOLOv5n
  
  Author(s):Wang, Jiale; Bai, Zhe; Zhang, Ximing; Qiu, Yuehong
  Source: REMOTE SENSING  Volume: 16  Issue: 5  DOI: 10.3390/rs16050857  Published: 2024  
  Abstract:Due to the issues of remote sensing object detection algorithms based on deep learning, such as a high number of network parameters, large model size, and high computational requirements, it is challenging to deploy them on small mobile devices. This paper proposes an extremely lightweight remote sensing aircraft object detection network based on the improved YOLOv5n. This network combines Shufflenet v2 and YOLOv5n, significantly reducing the network size while ensuring high detection accuracy. It substitutes the original CIoU and convolution with EIoU and deformable convolution, optimizing for the small-scale characteristics of aircraft objects and further accelerating convergence and improving regression accuracy. Additionally, a coordinate attention (CA) mechanism is introduced at the end of the backbone to focus on orientation perception and positional information. We conducted a series of experiments, comparing our method with networks like GhostNet, PP-LCNet, MobileNetV3, and MobileNetV3s, and performed detailed ablation studies. The experimental results on the Mar20 public dataset indicate that, compared to the original YOLOv5n network, our lightweight network has only about one-fifth of its parameter count, with only a slight decrease of 2.7% in mAP@0.5. At the same time, compared with other lightweight networks of the same magnitude, our network achieves an effective balance between detection accuracy and resource consumption such as memory and computing power, providing a novel solution for the implementation and hardware deployment of lightweight remote sensing object detection networks.
  Accession Number: 857
  ISSN:
  eISSN: 2072-4292
• Record 107 of
  
  Title:Design of Mantis-Shrimp-Inspired Multifunctional Imaging Sensors with Simultaneous Spectrum and Polarization Detection Capability at a Wide Waveband
  
  Author(s):Wang, Tianxin; Wang, Shuai; Gao, Bo; Li, Chenxi; Yu, Weixing
  Source: SENSORS  Volume: 24  Issue: 5  DOI: 10.3390/s24051689  Published: 2024  
  Abstract:The remarkable light perception abilities of the mantis shrimp, which span a broad spectrum ranging from 300 nm to 720 nm and include the detection of polarized light, serve as the inspiration for our exploration. Drawing insights from the mantis shrimp's unique visual system, we propose the design of a multifunctional imaging sensor capable of concurrently detecting spectrum and polarization across a wide waveband. This sensor is able to show spectral imaging capability through the utilization of a 16-channel multi-waveband Fabry-Perot (FP) resonator filter array. The design incorporates a composite thin film structure comprising metal and dielectric layers as the reflector of the resonant cavity. The resulting metal-dielectric composite film FP resonator extends the operating bandwidth to cover both visible and infrared regions, specifically spanning a broader range from 450 nm to 900 nm. Furthermore, within this operational bandwidth, the metal-dielectric composite film FP resonator demonstrates an average peak transmittance exceeding 60%, representing a notable improvement over the metallic resonator. Additionally, aluminum-based metallic grating arrays are incorporated beneath the FP filter array to capture polarization information. This innovative approach enables the simultaneous acquisition of spectrum and polarization information using a single sensor device. The outcomes of this research hold promise for advancing the development of high-performance, multifunctional optical sensors, thereby unlocking new possibilities in the field of optical information acquisition.
  Accession Number: 1689
  ISSN:
  eISSN: 1424-8220
• Record 108 of
  
  Title:Location and spectral extraction algorithm for a static broadband snapshot imaging spectrometer
  
  Author(s):Wang, Zhipeng; Yang, Qinghua; Li, Bingbin; Wang, Weiqiang
  Source: OPTICAL ENGINEERING  Volume: 63  Issue: 3  DOI: 10.1117/1.OE.63.3.035103  Published: 2024  
  Abstract:A location algorithm and a spectral extraction algorithm for a static broadband snapshot imaging spectrometer (SBSIS) are presented. The high-energy target is dispersed into a V-shaped pseudo-image (VPI) in the focal plane of the SBSIS. The location algorithm accurately calculates the target azimuth based on the one-to-one mapping relationship between the intersection position of the extension lines of the two arms of the VPI and the azimuth of the target. The spectral extraction algorithm is described to extract the characteristic spectrum of the target based on the azimuth angle of the target and the VPI.
  Accession Number:
  ISSN: 0091-3286
  eISSN: 1560-2303