2024

• Record 37 of
  
  Title:Cold shield matching of cooled infrared system based on telecentric optical structure
  
  Author(s):Hu, Xinrong(1); Wang, Jing(1); Chen, Su(1); Li, Jing(2); Feng, Ye(2)
  Source:Proceedings of SPIE - The International Society for Optical Engineering
  Volume: 13104  Issue:   DOI: 10.1117/12.3023902  Published: 2024  
  Abstract:To solve the problem of cold shield matching in a cooled infrared (IR) imaging optical system with aperture stop placed away from the lens, a pupil matching method based on the telecentric optical structure is proposed. The formulae of Gaussian parameters between the relay lens and the objective lens are derived by using the ideal imaging process. A specific discussion and numerical analysis are carried out. The objective lens is designed as image-space telecentric and the relay lens is designed as object-space telecentric to achieve the requirement that the aperture stop far away from the objective lens. And a specific designing example is added to show the effectiveness of the analysis. © COPYRIGHT SPIE. Downloading of the abstract is permitted for personal use only.
  Accession Number: 20241816027603
• Record 38 of
  
  Title:Tracking control of flexible link manipulator with joint space constraints
  
  Author(s):Jing, Feng(1,2); Ma, Caiwen(1,2); Cao, Yu(1); Xie, Meilin(1); Wang, Fan(1); Liu, Peng(1); Fan, Xiao(1)
  Source:Journal of Physics: Conference Series
  Volume: 2787  Issue: 1  DOI: 10.1088/1742-6596/2787/1/012043  Published: 2024  
  Abstract:A controller design with system uncertainties, external disturbances, and joint space constraints for a flexible link manipulator (FLM) is presented in this paper. To overcome the lumped disturbance and ensure that the joint space constraints are not violated, a finite-time extended state observer (ESO) and a barrier Lyapunov function are constructed. Using Lyapunov's theory, the error of the system is proved to be semi-globally ultimately uniformly bounded without violating the constraints. Finally, the rationality of the proposed methodology is verified by numerical simulation. © Published under licence by IOP Publishing Ltd.
  Accession Number: 20242816660786
• Record 39 of
  
  Title:A 4×112Gbps Compact Polarization-Insensitive Silicon Photonic WDM Receiver
  
  Author(s):Xue, Jintao(1,2); Wu, Jinyi(1,3); Cheng, Chao(1,3); Zhang, Wenfu(1,2); Wang, Binhao(1,2)
  Source:2024 Optical Fiber Communications Conference and Exhibition, OFC 2024 - Proceedings
  Volume:   Issue:   DOI:   Published: 2024  
  Abstract:A 4×112Gbps polarization-insensitive silicon photonic WDM receiver with a two-dimensional grating coupler, cascaded dual-ring filters and bidirectional photodiodes is demonstrated. A polarization-dependent loss of 0.45dB is achieved. © 2024 OSA.
  Accession Number: 20242216177152
• Record 40 of
  
  Title:Broadband Mid-infrared Kerr Comb Generation in Suspended AlGaAs Microresonators
  
  Author(s):Zhang, Yuqian(1); Sun, Qibing(2,3); Xiong, Bing(1); Wang, Jian(1); Hao, Zhibiao(1); Wang, Lai(1); Han, Yanjun(1); Li, Hongtao(1); Can, Lin(1); Luo, Yi(1); Wang, Leiran(2,3); Zhang, Wenfu(2,3); Sun, Changzheng(1)
  Source:16th Pacific Rim Conference on Lasers and Electro-Optics, CLEO-PR 2024
  Volume:   Issue:   DOI: 10.1109/CLEO-PR60912.2024.10676524  Published: 2024  
  Abstract:Suspended AlGaAs microring resonator is formed by optimized plasma dry-etching and surface treatment. Mid-infrared Kerr comb generation covering from 1250 nm to 5450 nm is demonstrated with a pump at 2.7 μm. © 2024 IEEE.
  Accession Number: 20244217212834
• Record 41 of
  
  Title:Design of a large-range dispersive objective for line-sweep spectral confocal displacement sensors
  
  Author(s):Yang, Weiguang(1,2); Qi, Meijie(1); Yan, Jiayue(1,2); Cheng, Mohan(1,2); Zhang, Zhoufeng(1)
  Source:Proceedings of SPIE - The International Society for Optical Engineering
  Volume: 13153  Issue:   DOI: 10.1117/12.3013278  Published: 2024  
  Abstract:Spectral Confocal Displacement Sensor is a new type of displacement sensor that can meet the requirements of high precision, high speed and non-destructive testing, and can be applied in aerospace, medical and industrial testing fields. The traditional point-scan spectral confocal displacement sensor only collects depth information of one point at a time, which is slow and has a large amount of back-end data. In order to improve the scanning speed of the point-scan spectral confocal displacement sensor and reduce the workload of data processing, it is proposed to extend the point-scan type to line-scan type, which can obtain the depth information of thousands of points at one time, improve the scanning speed and reduce the workload of data processing by processing all the points on the scanning line at one time. Aiming at the dispersive objective lens design in the line-scan spectral confocal displacement sensor, a dispersive lens with a large linear dispersion range is designed based on the principle of linear axial chromatic aberration design. The lens consists of four single lenses and two double-glued lenses and a beam-splitting prism, in order to solve the problem of energy uniformity into the spectrometer and the problem of uniformity of illumination on the image surface, the double telecentric optical path design is adopted, and the size of the detector element selected is 5.5 um, and the Nyquist cutoff frequency is 91 Lp/mm. The design results show that: the dispersive range of the lens reaches 3 mm, and the length of the scanning line reaches 10 mm. At the Nyquist cutoff frequency, the MTF value of the whole field of view is greater than 0.6, which indicates that the system has good imaging quality. © COPYRIGHT SPIE. Downloading of the abstract is permitted for personal use only.
  Accession Number: 20242016087065
• Record 42 of
  
  Title:Excitation of pure quartic platicon in optical microresonators
  
  Author(s):Liu, Mulong(1); Zhu, Haotong(1); Huang, Huimin(2); Lu, Zhizhou(3); Dang, Yaai(1); Mei, Sen(1); Cai, Yanan(1); Wang, Yuanyuan(1); Zhou, Wenquan(1); Zhao, Wei(4)
  Source:Optics Express
  Volume: 32  Issue: 21  DOI: 10.1364/OE.532950  Published: October 7, 2024  
  Abstract:We analytically derive the formulas of the threshold pump intensity and the range of possible detuning for the initiation of the pure quartic platicon (PQP) in the presence of multiphoton absorption, free-carrier absorption, and free-carrier dispersion. Theoretical investigations demonstrate a feasible approach for the excitation of PQP in the normal quartic dispersion regime via the free-carrier effects in platforms such as silicon, germanium, and their derivates. Due to the time-variant nonlinear loss related to free-carrier absorption or additional nonlinear detuning induced by free-carrier plasma dispersion, PQP can be generated through turn-key or laser frequency scanning schemes in both the three- and four-photon absorption regimes. Parameter spaces associated with varying detuning and free-carrier lifetime for the different dark, oscillating, and bright PQP states are revealed in the turn-key generation case. Such solitonic pulses are more energetic than conventional quadratic solitons with the same pulse width, especially for shorter pulse operations. In the spectral domain, PQP microcombs in the mid-infrared are desired for spectroscopy. These findings will facilitate the generation and manipulation of PQP and present promising potential for Kerr microcomb related applications. © 2024 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement.
  Accession Number: 20244117179466
• Record 43 of
  
  Title:Simplified design method for optical imaging systems based on deep learning
  
  Author(s):Xue, Ben(1,2); Wei, Shijie(1); Yang, Xihang(1); Ma, Yinpeng(1,2); Xi, Teli(1,3); Shao, Xiaopeng(4)
  Source:Applied Optics
  Volume: 63  Issue: 28  DOI: 10.1364/AO.530390  Published: October 1, 2024  
  Abstract:Modern optical design methods pursue achieving zero aberrations in optical imaging systems by adding lenses, which also leads to increased structural complexity of imaging systems. For given optical imaging systems, directly reducing the number of lenses would result in a decrease in design degrees of freedom. Even if the simplified imaging system can satisfy the basic first-order imaging parameters, it lacks sufficient design degrees of freedom to constrain aberrations to maintain the clear imaging quality. Therefore, in order to address the issue of image quality defects in the simplified imaging system, with support of computational imaging technology, we proposed a simplified spherical optical imaging system design method. The method adopts an optical-algorithm joint design strategy to design a simplified optical system to correct partial aberrations and combines a reconstruction algorithm based on the ResUNet++ network to correct residual aberrations, achieving mutual compensation correction of aberrations between the optical system and the algorithm. We validated our method on a two-lens optical imaging system and compared the imaging performance with that of a three-lens optical imaging system with similar first-order imaging parameters. The imaging results show that the quality of reconstructed images of the two-lens imaging system has improved (SSIM improved 13.94%, PSNR improved 21.28%), and the quality of the reconstructed image is close to the quality of the direct imaging results of the three-lens optical imaging system. © 2024 Optica Publishing Group. All rights, including for text and data mining (TDM), Artificial Intelligence (AI) training, and similar technologies, are reserved.
  Accession Number: 20244217188408
• Record 44 of
  
  Title:Depth-resolved imaging through dynamic scattering media via speckle cross-correlation under near-infrared illumination
  
  Author(s):Wang, Ping(1,2); Zhou, Meiling(2); Zhang, Yang(2,3); Li, Runze(2); Peng, Tong(2); Zhou, Yuan(2,3); Min, Junwei(2); Yao, Cuiping(1); Yao, Baoli(2,3)
  Source:Journal of Physics D: Applied Physics
  Volume: 57  Issue: 39  DOI: 10.1088/1361-6463/ad5c70  Published: October 4, 2024  
  Abstract:Speckle cross-correlation imaging (SCCI) method has the depth-resolved capability, benefiting from the introduction of a reference point. However, the quality of the reconstructed image is degraded due to the background noise, which becomes more prominent when imaging through dynamic scattering media. Here, we propose a composite-differential filter-assisted (CDF-SCCI) method, allowing for effectively reducing the background noise of the reconstructed image. The signal-to-background ratios of the reconstructed images by employing the CDF-SCCI method can be enhanced by a maximum of 4.15 dB (corresponding to 2.6 times) compared to the SCCI method. Furthermore, we apply the near-infrared (NIR) illumination to the imaging system of dynamic scattering media and prove that the NIR illumination not only enhances the penetration depth of imaging, but also improves the quality of reconstructed images compared to the visible illumination. The depth-resolved imaging through various dynamic biological scattering media, including the milk and anticoagulated pig blood, further demonstrates the potential application of the proposed CDF-SCCI method in biomedical imaging. © 2024 IOP Publishing Ltd.
  Accession Number: 20242816696258
• Record 45 of
  
  Title:Archimedes spiral optical vortex array emitter
  
  Author(s):Xin, M.A.(1); Wang, Ruoyu(1); Zhang, Hao(1); Tang, Miaomiao(1); Yuping, T.A.I.(1,2); Xinzhong, L.I.(1,2,3)
  Source:Optics Express
  Volume: 32  Issue: 13  DOI: 10.1364/OE.523806  Published: June 17, 2024  
  Abstract:Optical vortex arrays (OVAs) are important for large-capacity optical communications, optical tweezers, and optical imaging. However, there is an urgent need to generate an optical vortex emitter to construct a specific OVA with a functional structure for the accurate transport of particles. To address this issue, we propose an Archimedes spiral OVA emitter that uses an Archimedes spiral parametric equation and coordinate localization techniques to dynamically regulate the position of each optical vortex. We discuss the phenomena of the location coordinates and Archimedes spiral from unclosed to closed on the OVA emitter. Furthermore, the propose of multiple OVA emitters demonstrates a chiral structure that has the potential for optical material processing. This study lays the foundation for generating OVAs with functional structures, which will facilitate advanced applications in the complex manipulation, separation, and transport of multiple particles. © 2024 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement.
  Accession Number: 20242616421937
• Record 46 of
  
  Title:Topological edge states in a photonic Floquet insulator with unpaired Dirac cones
  
  Author(s):Zhong, Hua(1); Kartashov, Yaroslav V.(2); Li, Yongdong(1); Li, Ming(3); Zhang, Yiqi(1)
  Source:Photonics Research
  Volume: 12  Issue: 10  DOI: 10.1364/PRJ.524824  Published: October 1, 2024  
  Abstract:Topological insulators are most frequently constructed using lattices with specific degeneracies in their linear spectra, such as Dirac points. For a broad class of lattices, such as honeycomb ones, these points and associated Dirac cones generally appear in non-equivalent pairs. Simultaneous breakup of the time-reversal and inversion symmetry in systems based on such lattices may result in the formation of the unpaired Dirac cones in bulk spectrum, but the existence of topologically protected edge states in such structures remains an open problem. Here a photonic Floquet insulator on a honeycomb lattice with unpaired Dirac cones in its spectrum is introduced that can support unidirectional edge states appearing at the edge between two regions with opposite sublattice detuning. Topological properties of this system are characterized by the nonzero valley Chern number. Remarkably, edge states in this system can circumvent sharp corners without inter-valley scattering even though there is no total forbidden gap in the spectrum. Our results reveal unusual interplay between two different physical mechanisms of creation of topological edge states based on simultaneous breakup of different symmetries of the system. © 2024 Chinese Laser Press.
  Accession Number: 20244217196367
• Record 47 of
  
  Title:Efficient generation of broadband photon pairs in shallow-etched lithium niobate nanowaveguides
  
  Author(s):Fang, Xiao-Xu(1,2); Wang, Leiran(3,4); Lu, He(1,2)
  Source:Optics Express
  Volume: 32  Issue: 13  DOI: 10.1364/OE.519265  Published: June 17, 2024  
  Abstract:We design and fabricate shallow-etched periodically poled lithium niobate waveguides to realize highly efficient broadband spontaneous parametric down-conversion (SPDC) on nanophotonic chips. The shallow-etched waveguide can tolerate the non-uniformities of waveguide width induced by fabrication imperfections, enabling the generation of photon pairs with high count rate and bandwidth. We demonstrate photon-pair generation with a high brightness of 11.7 GHz/mW and bandwidth of 22 THz in a 5.7-mm-long PPLN waveguide. The generated photon pairs exhibit a strong temporal correlation with a coincidence-to-accidental ratio of up to 16262±850. Our results confirm the feasibility of shallow etching in the fabrication of an efficient SPDC device on the platform of lithium niobate on an insulator, and benefit quantum information processing with a broadband photon source. © 2024 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement.
  Accession Number: 20242616354357
• Record 48 of
  
  Title:Optomechanical design analysis and development of space-based visible coded spectrometer based on curved prism dispersion
  
  Author(s):Jia, Xinyin(1); Wang, Feicheng(1); Liu, Jia(1,2,3,4); Zhang, Zhanghui(1); Li, Siyuan(1); Yang, Ying(1); Hu, Bingliang(1); He, Xianqiang(2); Liu, Yupeng(3)
  Source:Journal of Optics (India)
  Volume: 53  Issue: 4  DOI: 10.1007/s12596-023-01544-9  Published: September 2024  
  Abstract:The coded spectrometer, a relatively new instrument, has the advantage of high signal-to-noise ratio, giving it great application potential. We report the optical design of a space-based visible coded spectrometer based on curved prism dispersion (SVCS-CPD) and further explore the design and analysis of its support structure. A static simulation and modal analysis, sinusoidal vibration mechanical analysis, and random vibration mechanical analysis were performed to demonstrate the excellent mechanical and thermal stability of the support structure. To realize rapid assembly and integration of the off-axis optical system, a point source microscope and three-coordinate measuring machines were employed. In addition, tests of optical design parameters and outdoor push-scan imaging were conducted to validate the high imaging performance of the SVCS-CPD. The results showed that the modulation transfer functions of the SVCS-CPD in the central and marginal fields of view were 0.61 at 31.25 line pairs/mm and 0.53 at 31.25 line pairs/mm, respectively. In addition, the spectral smile and spectral keystone were © The Author(s), under exclusive licence to The Optical Society of India 2023.
  Accession Number: 20235215294376