2020

• Record 505 of
  
  Title:Strongly enhanced four wave mixing in micro-ring resonators integrated with 2D graphene oxide films
  
  Author(s):Moss, David J.(1); Wu, Jiayang(1); Yang, Yunyi(1); Zhang, Yuning(1); Qu, Yang(1); Jia, Linnan(1); Xu, Xingyuan(1); Chu, Sai T.(2); Little, Brent E.(3); Morandotti, Roberto(4); Jia, Baohua(1)
  Source: TechRxiv  Volume:   Issue:   DOI: 10.36227/techrxiv.12893333  Published: August 29, 2020  
  Abstract:Two-dimensional layered graphene oxide films are integrated with micro-ring resonators to experimentally demonstrate enhanced four-wave mixing, achieving up to ~7.6-dB enhancement in conversion efficiency for a uniformly coated device and ~10.3-dB for a patterned device. © 2020, CC BY.
  Accession Number: 20220138455
• Record 506 of
  
  Title:Long distance measurement using single soliton microcomb
  
  Author(s):Wang, Jindong(1); Lu, Zhizhou(2,3); Wang, Weiqiang(2); Zhang, Fumin(1); Chen, Jiawei(1); Wang, Yang(2,3); Zhao, Xianyu(1); Zheng, Jihui(1); Chu, Sai T.(4); Zhao, Wei(2,3); Little, Brent E.(2,3); Qu, Xinghua(1); Zhang, Wenfu(2,3)
  Source: arXiv  Volume:   Issue:   DOI: null  Published: February 18, 2020  
  Abstract:Dispersive interferometry (DPI) takes a major interest in optical frequency comb (OFC) based long distance laser-based light detection and ranging (LIDAR) for the merits of strong anti-interference ability and long coherent length. However, the mismatch between the repetition rate of OFC and the resolution of optical spectrum acquisition system induces a large dead-zone which is a major obstacle for practical applications. Here, a new DPI LIDAR on the strength of high-repetition-rate soliton microcomb is demonstrated, which reaches a minimum Allan deviation of 27 nm for an outdoor 1179 m ranging experiment. The proposed scheme approaches a compact, high-accuracy, and none-dead-zone long distance ranging system, opening up new opportunities for emerging applications of frontier scientific researches and advanced manufacturing. Copyright © 2020, The Authors. All rights reserved.
  Accession Number: 20200525471
• Record 507 of
  
  Title:Imaging properties of generalized composite aperiodic zone plates
  
  Author(s):Xia, Tian(1,2,3); Cheng, Shubo(4); Tao, Shaohua(1,5); Yu, Weixing(2)
  Source: Optics Express  Volume: 28  Issue: 18  DOI: 10.1364/OE.402957  Published: August 31, 2020  
  Abstract:Generalized composite aperiodic zone plates (GCAZPs) are proposed to generate clearer images at focal planes. The images can be produced by a target object at infinity based on a collimator. The proposed zone plate consists of the proposed radial zone plate (RZP), whose original radius is not zero, and the common aperiodic zone plate, which has the coincident first-order diffraction area and the same axial first-order diffraction intensity distribution. The GCAZPs are applicable for the other aperiodic zone plates. Moreover, the modulation transfer function curve of the GCAZP is basically above that of the corresponding common aperiodic zone plate. Compared with the common aperiodic zone plates, the GCAZPs have the foci with higher intensity and the images with higher contrast at the same focal planes. In addition, a GCAZP with an arbitrary size can be designed. The construction method of the GCAZP is illustrated in details. Furthermore, it has been also proved numerically and experimentally that the GCAZPs are used to generate the clearer images than the corresponding common aperiodic zone plates. The proposed zone plates are applicable to generate clear images and trap particles stably at multiple planes simultaneously. © 2020 Optical Society of America under the terms of the OSA Open Access Publishing Agreement
  Accession Number: 20203709164861
• Record 508 of
  
  Title:Development of space-based diffractive telescopes
  
  Author(s):Zhao, Wei(1,3,4); Wang, Xin(1); Liu, Hua(2,4); Lu, Zi-feng(2,4); Lu, Zhen-wu(5)
  Source: Frontiers of Information Technology and Electronic Engineering  Volume: 21  Issue: 6  DOI: 10.1631/FITEE.1900529  Published: June 1, 2020  
  Abstract:Membrane diffractive optical elements formed by fabricating microstructures on the substrates have two important characteristics, ultra-light mass (surface mass density 2) and loose surface shape tolerances (surface accuracy requirements are on the order of magnitude of centimeter). Large-aperture telescopes using a membrane diffractive optical element as the primary lens have super large aperture, light weight, and low cost at launch. In this paper, the research and development on space-based diffractive telescopes are classified and summarized. First, the imaging theory and the configuration of diffractive-optics telescopes are discussed. Then, the developments in diffractive telescopes are introduced. Finally, the development prospects for this technology used as a high-resolution space reconnaissance system in the future are summarized, and the critical and relevant work that China should carry out is put forward. © 2020, Zhejiang University and Springer-Verlag GmbH Germany, part of Springer Nature.
  Accession Number: 20201708505402
• Record 509 of
  
  Title:Novel direct remaining useful life estimation of aero-engines with randomly assigned hidden nodes
  
  Author(s):Bai, Jian-Ming(1,2); Zhao, Guang-She(3); Rong, Hai-Jun(1)
  Source: Neural Computing and Applications  Volume: 32  Issue: 18  DOI: 10.1007/s00521-019-04478-1  Published: September 1, 2020  
  Abstract:This paper aims to improve data-driven prognostics by presenting a novel approach of directly estimating the remaining useful life (RUL) of aero-engines without requiring setting any failure threshold information or estimating degradation states. Specifically, based on the sensory data, RUL estimations are directly obtained through the universal function approximation capability of the extreme learning machine (ELM) algorithm. To achieve this, the features related with the RUL are first extracted from the sensory data as the inputs of the ELM model.Besides, to optimize the number of observed sensors, three evaluation metrics of correlation, monotonicity and robustness are defined and combined to automatically select the most relevant sensor values for more effective and efficient remaining useful life predictions. The validity and superiority of the proposed approach is evaluated by the widely used turbofan engine datasets from NASA Ames prognostics data repository.The proposed approach shows improved RUL estimation applicability at any time instant of the degradation process without determining the failure thresholds. This also simplifies the RUL estimation procedure. Moreover, the random properties of hidden nodes in the ELM learning mechanisms ensures the simplification and efficiency for real-time implementation. Therefore, the proposed approach suits to real-world applications in which prognostics estimations are required to be fast. © 2019, Springer-Verlag London Ltd., part of Springer Nature.
  Accession Number: 20194407592745
• Record 510 of
  
  Title:High-Resolution Hyperspectral Microscopic Imaging with Single Acousto-Optic Tunable Filter Based on Double Filtering
  
  Author(s):Zhang, Xiaofa(1); Zhang, Chunguang(1); Wang, Yupuyun(1); Wang, Hao(1,2); Sheng, Zhenfei(1); Tan, Zhiwei(1); Qiu, Weijie(1); Huang, Xi(1); Wang, Pengchong(1,2); Liu, Wenyao(3); Tong, Haiping(1); Liu, Yuhao(1); Wang, Xiansheng(1)
  Source: IEEE Access  Volume: 8  Issue:   DOI: 10.1109/ACCESS.2019.2963369  Published: 2020  
  Abstract:Hyperspectral imaging is a technique that integrates multiple spectral bands and image information. Its applications range from improving the accuracy of cancer diagnosis to testing the quality of products. Here, we introduce a double-filtering technique that provides high-resolution diagnostic histological images within minutes. The hyperspectral microscopic imaging system is built based on an acousto-optic tunable filter (AOTF). The optimized system is analyzed from the perspective of spectrum and imaging. The spectral resolution can be improved by 37.08 % to 59.95% in the visible light range. The side lobe is obviously inhibited and the purity of spectrum is improved. Furthermore, the example of hyperspectral microscopic imaging is demonstrated with unstained gastric cancer tissue sections to assess the ability of the system in terms of its spectral performances and image quality. The microscopic imaging results of single filtering optical path system and single crystal double filtering optical path system are compared. In general, the optimized double filtering system achieves excellent performance in bandwidth compression and side lobe suppression, especially the first application of hyperspectral microscopy combined with microscope in the visible light range. © 2013 IEEE.
  Accession Number: 20200508112959
• Record 511 of
  
  Title:Long-distance ranging with high precision using a soliton microcomb
  
  Author(s):Wang, Jindong(1); Lu, Zhizhou(2,3); Wang, Weiqiang(2); Zhang, Fumin(1); Chen, Jiawei(1); Wang, Yang(2,3); Zheng, Jihui(1); Chu, Sai T.(4); Zhao, Wei(2,3); Little, Brent E.(2,3); Qu, Xinghua(1); Zhang, Wenfu(2,3)
  Source: Photonics Research  Volume: 8  Issue: 12  DOI: 10.1364/PRJ.408923  Published: 2020  
  Abstract:Laser-based light detection and ranging (lidar) plays a significant role in both scientific and industrial areas. However, it is difficult for existing lidars to achieve high speed, high precision, and long distance simultaneously. Here, we demonstrate a high-performance lidar based on a chip-scaled soliton microcomb (SMC) that can realize all three specialties simultaneously. Aided by the excellent properties of ultrahigh repetition rate and the smooth envelope of the SMC, traditional optical frequency comb (OFC)-based dispersive interferometry is heavily improved and the measuring dead zone induced by the mismatch between the repetition rate of the OFC and resolution of the optical spectrum analyzer is totally eliminated. Combined with an auxiliary dual-frequency phase-modulated laser range finder, the none-dead-zone measurable range ambiguity is extended up to 1500 m. The proposed SMC lidar is experimentally implemented in both indoor and outdoor environment. In the outdoor baseline field, real-time, high-speed (up to 35 kHz) measurement of a long distance of ∼1179 m is achieved with a minimum Allan deviation of 5.6 μm at an average time of 0.2 ms (27 nm at an average time of 1.8 s after high-pass filtering). The present SMC lidar approaches a compact, fast, high-precision, and none-dead zone long-distance ranging system, aimed at emerging applications of frontier basic scientific research and advances in industrial manufacturing. © 2020 Chinese Laser Press
  Accession Number: 20210109713625
• Record 512 of
  
  Title:Third-harmonic generation in CMOS-compatible highly doped silica micro-ring resonator
  
  Author(s):Li, Yuhua(1); Wang, Shao Hao(2); Tian, Yayuan(3); Ho, Wai Lok(1); Li, Yangyang(3); Wang, Leiran(4,5); Davidson, Roy R.(6); Little, Brent E.(4); Chu, Sai Tak(1)
  Source: Optics Express  Volume: 28  Issue: 1  DOI: 10.1364/OE.28.000641  Published: 2020  
  Abstract:We present the first demonstration of visible emission from highly doped silica glass micro-ring resonators (MRRs) through a third-harmonic generation (THG) nonlinear process. We obtain green light conversion efficiency of 2.7×10−5 W−2 in a MRR with loaded Q-factor of 1.4×106 pumped in the telecom band. A thermal nonlinear model is developed to account for the in-cavity power dependence of the resonance detuning. Using the extracted thermal nonlinear coefficients, the measured TH resonance shift is calibrated by subtracting the thermal nonlinear-induced phase mismatch to obtain the theoretical threefold wavelength relationship along with the measured cubic power relationship. © 2020 Optical Society of America under the terms of the OSA Open Access Publishing Agreement.
  Accession Number: 20200408064945
• Record 513 of
  
  Title:The backbone-residual model: Accurately characterising the instrumental profile of a fibre-fed echelle spectrograph
  
  Author(s):Hao, Zhibo(1,2,4); Ye, Huiqi(1,2); Han, Jian(1,2); Tang, Liang(1,2); Zhai, Yang(1,2); Xiao, Dong(1,2); Zhu, Yongtian(1,2,4); Zhang, Kai(1,2); Wang, Liang(1,2); Zhao, Gang(3); Zhao, Fei(3); Wang, Huijuan(3,4); Zheng, Jie(3); Liu, Yujuan(3); Wang, Jiaqi(3,4); Wei, Ruyi(5); Yan, Qiangqiang(5)
  Source: arXiv  Volume:   Issue:   DOI: null  Published: May 16, 2020  
  Abstract:Context. Instrumental profile (IP) is the basic property of a spectrograph. Accurate IP characterisation is the prerequisite of accurate wavelength solution. It also facilitates new spectral acquisition methods such as the forward modeling and deconvolution. Aims. We investigate an IP modeling method for the fibre-fed echelle spectrograph with the emission lines of the ThAr lamp, and explore the method to evaluate the accuracy of IP characterisation. Methods. The backbone-residual (BR) model is put forward and tested on the fibre-fed High Resolution Spectrograph (HRS) at the Chinese Xinglong 2.16-m Telescope, which is the sum of the backbone function and the residual function. The backbone function is a bell-shaped function to describe the main component and the spatial variation of IP. The residual function, which is expressed as the cubic spline function, accounts for the difference between the bell-shaped function and the actual IP. The method of evaluating the accuracy of IP characterisation is based on the spectral reconstruction and Monte Carlo simulation. Results. The IP of HRS is characterised with the BR model, and the accuracy of the characterised IP reaches 0.006 of the peak value of the backbone function. This result demonstrates that the accurate IP characterisation has been achieved on HRS with the BR model, and the BR model is an excellent choice for accurate IP characterisation of fibre-fed echelle spectrographs. Copyright © 2020, The Authors. All rights reserved.
  Accession Number: 20200571714
• Record 514 of
  
  Title:Four-wave mixing in integrated ring resonators integrated with 2D graphene oxide
  
  Author(s):Moss, David J.(1); Wu, Jiayang(1); Yang, Yunyi(1); Zhang, Yuning(1); Qu, Yang(1); Jia, Linnan(1); Xu, Xingyuan(1); Chu, Sai T.(2); Little, Brent E.(3); Morandotti, Roberto(4,5); Jia, Baohua(1)
  Source: TechRxiv  Volume:   Issue:   DOI: 10.36227/techrxiv.12749840  Published: August 1, 2020  
  Abstract:We experimentally demonstrate enhanced four-wave mixing in micro-ring resonators (MRRs) integrated with graphene oxide films. We achieve up to ~7.6-dB enhancement in conversion efficiency for a uniformly coated MRR and ~10.3-dB for a patterned device. © 2020, CC BY.
  Accession Number: 20220139793
• Record 515 of
  
  Title:Construction and investigation of a planar waveguide in photo-thermal-refractive glass by proton implantation
  
  Author(s):Chen, Jing-Yi(1); Xie, Zhong-Hu(1); Li, Wei-Nan(2); Lin, She-Bao(3); Zhang, Liao-Lin(4); Liu, Chun-Xiao(1)
  Source: Optik  Volume: 207  Issue:   DOI: 10.1016/j.ijleo.2020.164461  Published: April 2020  
  Abstract:In this paper, the fabrication of optical planar waveguide in PTR glass by proton implantation is reported for the first time to our knowledge. The planar waveguide with a width of approximately 3.4 μm was generated under the condition of 400 keV H+ ion implantation with a dose of 8.0 × 1016 ions ‧ cm−2 at room temperature. The formation mechanism of PTR glass waveguide was illustrated with the aid of the SRIM program. The optical characteristics of the PTR waveguide, such as refractive index profile and near-field intensity distribution, were investigated in detail. The fabricated PTR waveguide presents a structure of both index-well and optical barrier according to the reconstructed refractive index profile. The finite-difference beam propagation method was carried out to simulate guiding modal distribution. Besides, in order to study the thermal stability of the H+-implanted PTR waveguide, annealing treatment was conducted at different temperatures. © 2020 Elsevier GmbH
  Accession Number: 20200908228845
• Record 516 of
  
  Title:Reversible optical binding force in a plasmonic heterodimer under radially polarized beam illumination
  
  Author(s):Xiao, Fajun(1,2); Zhang, Jiachen(1); Yu, Weixing(2); Zhu, Weiren(3); Mei, Ting(1); Premaratne, Malin(4); Zhao, Jianlin(1)
  Source: Optics Express  Volume: 28  Issue: 3  DOI: 10.1364/OE.380057  Published: February 3, 2020  
  Abstract:We investigated the optical binding force in a plasmonic heterodimer structure consisting of two nano-disks. It is found that when illuminated by a tightly focused radially polarized beam (RPB), the plasmon modes of the two nano-disks are strongly hybridized, forming bonding/antibonding modes. An interesting observation of this setup is that the direction of the optical binding force can be controlled by changing the wavelength of illumination, the location of the dimer, the diameter of the nano-disks, and the dimer gap size. Further analysis yields that the inhomogeneous polarization state of RPB can be utilized to readily control the bonding type of plasmon modes and distribute the underlying local field confined in the gap (the periphery) of the dimer, leading to a positive (negative) optical binding force. Our findings provide a clear strategy to engineer optical binding forces via changes in device geometry and its illumination profile. Thus, we envision a significant role for our device in emerging nanophotonics structures. © 2020 Optical Society of America under the terms of the OSA Open Access Publishing Agreement
  Accession Number: 20200608125151