2023

• Record 493 of
  
  Title:Asymmetric Calibration and Characterization for Diff-Port Magnetic Field Probing System
  
  Author(s):Shao, Weiheng(1,2); Li, Hui(3); Huang, Zhanjun(4); Tian, Xin-Xin(3); Ye, Lianghua(3); Chen, Yiqiang(1); He, Xiao(1)
  Source: IEEE Sensors Journal  Volume: 23  Issue: 10  Article Number: null  DOI: 10.1109/JSEN.2023.3265773  Published: May 15, 2023  
  Abstract:Strict symmetry limits the application of the differential port (diff-port) magnetic field probing system (DMPS). Asymmetric calibration is very meaningful for DMPS. Ultrawindband asymmetric calibration theory was first proposed and applied to the electromagnetic field measurement system. However, the asymmetric calibration theory is not clear for the DMPS because only the magnetic field is concerned. This article proposes an ultrawideband asymmetric calibration method (UACM) for the DMPS. The output voltage and asymmetric factor of the DMPS are redefined using the UACM. Compared with the previous asymmetric calibration method, the proposed method is based on a symmetry calibrator with a grounded coplanar waveguide (GCPW) structure. The proposed method is validated by eliminating a severe asymmetry in the DMPS, whose severe asymmetry is achieved by introducing a connector intentionally. The proposed method has been verified with a frequency of up to 20 GHz by measuring a standing wave magnetic field on an open-terminated transmission line. The key parameters of the DMPS, including unwanted field suppression, spatial resolution, and sensitivity, are also estimated. © 2001-2012 IEEE.
  Accession Number: 20231714017291
• Record 494 of
  
  Title:Quantifying the Accuracy of Microcomb-Based Photonic RF Transversal Signal Processors
  
  Author(s):Sun, Yang(1); Wu, Jiayang(1); Li, Yang(1); Tan, Mengxi(2); Xu, Xingyuan(3); Chu, Sai Tak(4); Little, Brent E.(5); Morandotti, Roberto(6); Mitchell, Arnan(2); Moss, David J.(1)
  Source: IEEE Journal of Selected Topics in Quantum Electronics  Volume: 29  Issue: 6  Article Number: 7500317  DOI: 10.1109/JSTQE.2023.3266276  Published: November 1, 2023  
  Abstract:Photonic RF transversal signal processors, which are equivalent to reconfigurable electrical digital signal processors but implemented with photonic technologies, are attractive for high-speed information processing. Optical microcombs are extremely powerful as sources for RF photonics since they can generate many wavelength channels from compact micro-resonators, offering greatly reduced size, power consumption, and complexity. Recently, a variety of signal processing functions have been demonstrated using microcomb-based photonic RF transversal signal processors. Here, we provide a detailed analysis for quantifying the processing accuracy of microcomb-based photonic RF transversal signal processors. First, we investigate the theoretical limitations of the processing accuracy determined by tap number, signal bandwidth, and pulse waveform. Next, we discuss the practical error sources from different experimental components of the signal processors. Finally, we assess the relative contributions of the two to the overall accuracy. We find that the overall accuracy is mainly limited by experimental factors when the processors are properly designed to minimize the theoretical limitations, and that these remaining errors can be further greatly reduced by introducing feedback control to calibrate the processors' impulse response. These results provide a useful guide for designing microcomb-based photonic RF transversal signal processors to optimize their accuracy. © 1995-2012 IEEE.
  Accession Number: 20231714015091
• Record 495 of
  
  Title:Redundant information model for Fourier ptychographic microscopy
  
  Author(s):Gao, Huiqin(1,2,3); Pan, An(1,3); Gao, Yuting(1,3); Zhang, Yu(1,4); Wan, Quanzhen(1,5); Mu, Tingkui(2); Yao, Baoli(1,3)
  Source: Optics Express  Volume: 31  Issue: 26  Article Number: null  DOI: 10.1364/OE.505407  Published: December 18, 2023  
  Abstract:Fourier ptychographic microscopy (FPM) is a computational optical imaging technique that overcomes the traditional trade-off between resolution and field of view (FOV) by exploiting abundant redundant information in both spatial and frequency domains for high-quality image reconstruction. However, the redundant information in FPM remains ambiguous or abstract, which presents challenges to further enhance imaging capabilities and deepen our understanding of the FPM technique. Inspired by Shannon’s information theory and extensive experimental experience in FPM, we defined the specimen complexity and reconstruction algorithm utilization rate and reported a model of redundant information for FPM to predict reconstruction results and guide the optimization of imaging parameters. The model has been validated through extensive simulations and experiments. In addition, it provides a useful tool to evaluate different algorithms, revealing a utilization rate of 24%±1% for the Gauss-Newton algorithm, LED Multiplexing, Wavelength Multiplexing, EPRY-FPM, and GS. In contrast, mPIE exhibits a lower utilization rate of 19%±1%. © 2023 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement.
  Accession Number: 20235115262618
• Record 496 of
  
  Title:Scalable Colored Subambient Radiative Coolers Based on a Polymer-Tamm Photonic Structure
  
  Author(s):Huang, Tianzhe(1,3); Chen, Qixiang(2); Huang, Jinhua(1); Lu, Yuehui(1); Xu, Hua(2); Zhao, Meng(4); Xu, Yao(5); Song, Weijie(1)
  Source: ACS Applied Materials and Interfaces  Volume: 15  Issue: 12  Article Number: null  DOI: 10.1021/acsami.2c23270  Published: March 29, 2023  
  Abstract:Daytime radiative coolers cool objects below the air temperature without any electricity input, while most of them are limited by a silvery or whitish appearance. Colored daytime radiative coolers (CDRCs) with diverse colors, scalable manufacture, and subambient cooling have not been achieved. We introduce a polymer-Tamm photonic structure to enable a high infrared emittance and an engineered absorbed solar irradiance, governed by the quality factor (Q-factor). We theoretically determine the theoretical thresholds for subambient cooling through yellow, magenta, and cyan CDRCs. We experimentally fabricate and observe a temperature drop of 2.6-8.8 °C on average during the daytime and 4.0-4.4 °C during the nighttime. Furthermore, we demonstrate a scalable-manufactured magenta CDRC with a width of 60 cm and a length of 500 cm by a roll-to-roll deposition technique. This work provides guidelines for large-scale CDRCs and offers unprecedented opportunities for potential applications with energy-saving, aesthetic, and visual comfort demands. © 2023 American Chemical Society.
  Accession Number: 20231213785680
• Record 497 of
  
  Title:Non-defocus high transmittance image slicer
  
  Author(s):Wei, Ruyi(1,2,3,4,5); Liu, Bin(2,5); Xie, Zhengmao(5); Wang, Yidong(2,5); Chen, Shasha(2,5); Zhang, Kai(6)
  Source: Optics Express  Volume: 31  Issue: 8  Article Number: null  DOI: 10.1364/OE.479623  Published: April 10, 2023  
  Abstract:The first non-defocus high transmittance non-fiber image slicer is presented. In order to solve the problem of image blur caused by the defocus between different sliced sub-images, an optical path compensation method based on stepped prism plate is proposed. Design results show that both the maximal defocus amount between the four sliced sub-images is reduced from 2.363 mm to nearly 0. The diameter of the dispersion spot on the focal plane is reduced from 98.47 µm to close to 0. The optical transmittance of the image slicer is up to 91.89%. This new image slicer is greatly valuable for high resolution and high transmittance spectrometer. © 2023 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement.
  Accession Number: 20231613895922
• Record 498 of
  
  Title:Kerr Frequency Comb and Stimulated Raman Comb Covering S+C+L+U Band Based on a Packaged Silica Spherical Microcavity
  
  Author(s):Wang, Mengyu(1); Fan, Lekang(1); Lu, Zhizhou(2); Guo, Zhuang(1); Cai, Ruitao(1); Tan, Qinggui(3); Jiang, Guangyu(1); Wu, Tao(1); Xie, Chengfeng(1); Fu, Yanjun(1); Wang, Keyi(4)
  Source: Journal of Lightwave Technology  Volume: 41  Issue: 1  Article Number: null  DOI: 10.1109/JLT.2022.3210647  Published: January 1, 2023  
  Abstract:Optical microresonators supported whispering gallery modes (WGMs) are one of the most cost-effective platforms for optical frequency comb generated due to their advantages of ultra-high quality (Q) factor and ultra-low mode volume. In this paper, we report a portable and robust packaged silica spherical microcavity by melting the end of a standard single-mode fiber with ultra-high Q factor up to 8$, and theoretically and experimentally demonstrate a broadband optical frequency comb (OFC) generation including Kerr OFC and stimulated Raman comb. Kerr OFCs are separated by one, two, eight and twelve free spectral ranges corresponding to 1.4, 2.8, 11.2, and 16.8 nm, respectively. The transition between Kerr OFC and stimulated Raman comb is achieved by changing the pump laser power and the detuning frequency resulting from gain competition between modulation instability and Raman gain. Benefitting from the dispersion control and ultra-high Q factor persistence in our packaged microcavity, OFC can be adjusted continuously covering from S-band to C-band, L-band and U-band. We also explain these results by numerical simulations using a model framework combined with the Lugiato-Lefever equation and Raman response function. © 1983-2012 IEEE.
  Accession Number: 20224112877781
• Record 499 of
  
  Title:3D-printed high-birefringence THz hollow-core anti-resonant fiber with an elliptical core
  
  Author(s):Xue, Lu(1); Sheng, Xinzhi(1); Mu, Qiyuan(2); Kong, Depeng(2); Wang, Zhaojin(3); Chu, Paul K.(4); Lou, Shuqin(5)
  Source: Optics Express  Volume: 31  Issue: 16  Article Number: null  DOI: 10.1364/OE.497258  Published: July 31, 2023  
  Abstract:A high-birefringence and low-loss terahertz (THz) hollow-core anti-resonant fiber (THz HC-ARF) is designed and analyzed numerically by the finite element method (FEM). The THz HC-ARF is composed of an elliptical tube as the core for high birefringence guidance and a pair of symmetrical slabs arranged vertically as the cladding to attain low loss. Numerical analysis indicates that the birefringence reaches 10-2 in the transmission window between 0.21 and 0.35 THz. The highest birefringence is 4.61 × 10-2 at 0.21 THz with a loss of 0.15 cm-1. To verify the theoretical results, the THz HC-ARF is produced by three-dimensional (3D) printing, and the transmission characteristics are determined by THz time-domain spectroscopy (THz-TDS). High birefringence in the range of 2.17 × 10-2 to 3.72 × 10-2 and low loss in the range of 0.12 to 0.18 cm-1 are demonstrated experimentally in the 0.2 to 0.27 THz transmission window. The highest birefringence is 3.72 × 10-2 at 0.22 THz and the corresponding loss is 0.18 cm-1. The THz HC-ARF shows the highest birefringence besides relatively low loss compared to similar THz HC-ARFs reported recently. © 2023 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement.
  Accession Number: 20233514642369
• Record 500 of
  
  Title:X-ray telescope for pulsar deep space reference and its development vision
  
  Author(s):Zhou, Qingyong(1,2); Wei, Ziqing(1,2); Lei, Yaohu(3); Liu, Siwei(1,2); Hao, Xiaolong(4); Wu, Fumei(1,2); Yang, Yanji(5); Qiang, Pengfei(6)
  Source: Hangkong Xuebao/Acta Aeronautica et Astronautica Sinica  Volume: 44  Issue: 3  Article Number: 526608  DOI: 10.7527/S1000-6893.2021.26608  Published: February 15, 2023  
  Abstract:Deep space reference is the basis for entering and utilizing space. X-ray telescopes are important observa⁃ tion equipment for constructing pulsar deep space reference. Firstly，the role of pulsar timing in the establishment of deep space reference is discussed，and the requirements of millisecond pulsar space observation on X-ray telescopes are qualitatively analyzed. Then the technical status and development trend of X-ray telescopes at home and abroad are systematically summarized. Secondly，considering the fact that the pulse signal is generally weak and the non-pulse signal and spatial dispersion background are strong in X-ray millisecond pulsar observation，a method for suppressing the non-pulse noise by using high-resolution imaging observation is proposed. A high-resolution low-noise X-ray telescope is then preliminarily designed. Finally，the effects of different pulse signal flow，non-pulse signal flow，angular resolution and lens reflection efficiency on the signal-to-noise ratio during the pulsar observation obtained by focusing imaging，focusing non-imaging and collimating non-imaging X-ray telescopes are analyzed. It is found that the focusing imaging X-ray telescope has better detection ability in the flow of weak pulse signal and strong non-pulse signal. The calculation result also shows that the detection sensitivity of the focusing imaging telescope is better than that of the X-ray Timing Instrument（XTI）of the Neutron star Interior Composition Explorer（NICER）under the same conditions during the observation of five navigation pulsars. It can be seen that the designed focusing imaging X-ray telescope can effectively improve the observation ability of millisecond X-ray pulsars，and provide time service for national comprehensive Positioning，Navigation & Timing（PNT）and the construction of deep space reference system. © 2023 AAAS Press of Chinese Society of Aeronautics and Astronautics. All rights reserved.
  Accession Number: 20232314186032
• Record 501 of
  
  Title:Infrared Imaging of Magnetic Octupole Domains in Non-collinear Antiferromagnets
  
  Author(s):Wang, Peng(1,2); Xia, Wei(3,4); Shen, Jinhui(1,5); Chen, Yulong(1,5); Peng, Wenzhi(1,5); Zhang, Jiachen(1,5); Pan, Haolin(1,5); Yu, Xuhao(1,5); Liu, Zheng(5,6); Gao, Yang(5,6); Niu, Qian(5,6); Xu, Zhian(3); Yang, Hongtao(7); Guo, Yanfeng(3,4); Hou, Dazhi(1,5)
  Source: arXiv  Volume: null  Issue: null  Article Number: null  DOI: 10.48550/arXiv.2311.08762  Published: November 15, 2023  
  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 the AEE originating from different magnetic domains is measured by the 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. Copyright © 2023, The Authors. All rights reserved.
  Accession Number: 20230423551
• Record 502 of
  
  Title:Snapshot imaging Mueller matrix polarimeter using modified Savart polariscopes
  
  Author(s):Cao, Qizhi(1); Jiang, Min(1); Jia, Chenling(2); Jiang, Siyue(1); Zhang, Jing(1); Yao, Baoli(3); Jin, Mingwu(4); Dehoog, Edward(5); Duan, Lian(6); Wang, Huahua(1); Deng, Ting(1); Fan, Dongxin(6)
  Source: Applied Optics  Volume: 62  Issue: 8  Article Number: null  DOI: 10.1364/AO.481493  Published: March 10, 2023  
  Abstract:We present a snapshot imaging Mueller matrix polarimeter using modified Savart polariscopes (MSP-SIMMP). The MSP-SIMMP contains both the polarizing optics and the analyzing optics encoding all Mueller matrix components of the sample into the interferogram by the spatial modulation technique. An interference model and the methods of reconstruction and calibration are discussed. To demonstrate the feasibility of the proposed MSP-SIMMP, the numerical simulation and the laboratory experiment of a design example are presented. The remarkable advantage of the MSP-SIMMP is easy to calibrate. Moreover, compared with conventional imaging Mueller matrix polarimeters with rotating parts, the advantage of the proposed instrument is simple, compact, snapshot-enabled, and stationary (no moving parts). © 2023 Optica Publishing Group.
  Accession Number: 20231513879200
• Record 503 of
  
  Title:Single-Mode Hollow-Core Anti-Resonant Waveguides for Low-Loss THz Wave Propagation
  
  Author(s):Xue, Lu(1); Sheng, Xinzhi(1); Mu, Qiyuan(2); Kong, Depeng(2); Wang, Zhaojin(3); Chu, Paul K.(4); Lou, Shuqin(5)
  Source: Journal of Infrared, Millimeter, and Terahertz Waves  Volume: 44  Issue: 9-10  Article Number: null  DOI: 10.1007/s10762-023-00938-x  Published: October 2023  
  Abstract:A single-mode hollow-core anti-resonant (HC-AR) waveguide designed for low-loss terahertz (THz) wave propagation is fabricated by three-dimensional (3D) printing. Compared to similar structures reported recently, the rotating-nested semi-elliptical tubes (SETs) in the HC-AR THz waveguide cladding suppress multiple high-order modes (LP11, LP21, and LP02 modes) at the same time giving rise to enhanced single-mode transmission and low losses. Three HC-AR THz waveguides with different wall thicknesses are produced using two photosensitive resins and analyzed by THz time-domain spectroscopy (THz-TDS). The experimental results show that the electric field distributions at the output end of these waveguides have a Gaussian-like distribution reflecting that of the single mode. The smallest transmission losses determined by the ‘cut-back’ method are 0.03 cm−1 at 0.31 THz for sample A, 0.02 cm−1 at 0.4 THz for sample B, and 0.01 cm−1 at 0.23 THz for sample C. The consistent experimental and simulated results reveal that the HC-AR THz waveguide has many advantages over current ones by achieving low losses and single-mode operation simultaneously. © 2023, The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.
  Accession Number: 20233414605244
• Record 504 of
  
  Title:Ultralow-Noise K-Band Soliton Microwave Oscillator Using Optical Frequency Division
  
  Author(s):Niu, Rui(1,2,3); Hua, Tian-Peng(2,4); Shen, Zhen(1,2,3); Wang, Yu(1,2,3); Wan, Shuai(1,2,3); Sun, Yu Robert(2,4); Wang, Weiqiang(5,6); Zhao, Wei(5,6); Guo, Guang-Can(1,2,3); Zhang, Wenfu(5,6); Liu, Wen(7); Hu, Shui-Ming(2,3,4); Dong, Chun-Hua(1,2,3)
  Source: ACS Photonics  Volume: null  Issue: null  Article Number: null  DOI: 10.1021/acsphotonics.3c01247  Published: 2023  
  Abstract:Compact, low-noise microwave oscillators are required throughout a wide range of applications such as radar systems, wireless networks, and frequency metrology. Optical frequency division via an optical frequency comb provides a powerful tool for low-noise microwave signal generation. Here, we experimentally demonstrate an optical reference down to 26 GHz frequency division based on the dissipative Kerr soliton comb, which is generated on a CMOS-compatible, high-index doped silica glass platform. The optical reference is generated through two continuous wave lasers locked to an ultralow expansion cavity. The dissipative Kerr soliton comb with a repetition rate of 26 GHz acts as a frequency divider to derive an ultralow-noise microwave oscillator, with a phase noise level of −101.3 dBc/Hz at a 100 Hz offset frequency and −132.4 dBc/Hz at a 10 kHz offset frequency. Furthermore, the Allan deviation of the oscillator reaches 6.4 × 10-13 at a 1 s measurement time. Our system is expected to provide an ultralow-noise microwave oscillator for future radar systems and the next generation of wireless networks. © 2024 American Chemical Society.
  Accession Number: 20241215760586