2020
2020
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Record 361 of
Title:Optical Path Design for Catadioptric Star Sensor with Large Aperture
Author(s):Li, Jian-Lin(1,2); Lei, Guang-Zhi(1); Bai, Yang(2); Wen, Yan(1); Lin, Shang-Min(1)Source: Guangzi Xuebao/Acta Photonica Sinica Volume: 49 Issue: 6 DOI: 10.3788/gzxb20204906.0611002 Published: June 1, 2020Abstract:In order to improve the ability of the star sensor to detect limited magnitude, a combination of the improved Cassegrain system, aperture-corrected spherical lens group and field-of-view corrected spherical lens group is adopted to design an optical system of a large aperture catadioptric star sensor capable of correcting astigmatism, field curvature and distortion, with the spectral range of 450~950 nm, the semifield of 1.4°, an entrance pupil diameter of 250 mm and the focal length of 425 mm. According to the calculation of the initial structure parameters of the system based on the aberration theory and the optimization design of Ray tracing in Zemax software, the blocking ratio of the secondary mirror of the optical system reaches 0.43, the energy concentration of the imaging point is 80% within 30 μm, and the maximum distortion is 0.081%. The modulation transfer function is greater than 0.75 at a Nyquist frequency of 34 lp/mm, and the maximum magnification chromatic aberration is 1.138 μm, which meets the imaging requirements of star sensor pairs. Through the tolerance analysis of optical system, in the 20 Monte Carlo analysis results, the best structure is the 13th structure with the performance function of 4.975 16 μm, the worst structure is the 20th structure with the performance function of 7.799 57 μm. Through the performance function analysis of 20 times Monte Carlo structure, the selected tolerance value can well meet the basic requirements of optical system performance, and provide the basis for the errors in the process of processing and installation. ? 2020, Science Press. All right reserved.Accession Number: 20202708899068 -
Record 362 of
Title:Design of hybrid refractive-diffractive infrared dual-band zoom optical system
Author(s):Yang, Hongtao(1); Yang, Xiaofan(1,2); Mei, Chao(1); Chen, Weining(1)Source: Hongwai yu Jiguang Gongcheng/Infrared and Laser Engineering Volume: 49 Issue: 10 DOI: 10.3788/IRLA20200036 Published: October 25, 2020Abstract:In this paper, the influence models of different diffraction elements on diffraction efficiency were established, and the diffraction efficiency among single diffraction element, harmonic diffraction element and double diffraction element was compared. The advantages of using double diffraction elements in infrared optical system were analyzed. The average diffraction efficiency of different material combinations was calculated. Based on this, a hybrid infrared dual-band and dual-field optical system suitable for airborne platform was designed. The resolution of the large field of view was 1.5 m@16 km. The long and the short focal length were 960 mm and 480 mm respectively. The zoom function was realized by switching the mirror to ensure the optical axis stability. The simulation results show that the MTF curves are smooth and close to the diffraction limit under the large temperature difference of ?40 - +60 ℃. The RMS radius is within the radius of airy spots, and the minimum characteristic size of the binary diffraction surface is 6.9 μm. The design results meet the engineering requirements. Copyright ?2020 Infrared and Laser Engineering. All rights reserved.Accession Number: 20204509457905 -
Record 363 of
Title:Design of Co-aperture Wide Spectrum Compound Eye Optical System
Author(s):Chen, Yang(1); Gao, Ming(1); Hu, Xue-Lei(1); Zhang, Xi-Bin(2); Jiao, Yang(3)Source: Guangzi Xuebao/Acta Photonica Sinica Volume: 49 Issue: 3 DOI: 10.3788/gzxb20204903.0322002 Published: March 1, 2020Abstract:In order to expand the receiving spectrum of the compound eye optical system, a visible light and long wave infrared wide spectrum compound eye optical system was studied. The dual-band ommatidia common image equation was derived, and the matching requirement between ommatidia and the receiving system was established. The ommatidia optical system has working bandwidths of 0.38~0.78 μm and 8~12 μm, a focal length of 5 mm, a relative aperture of 1:3, and a field of view of 10°. The imaging position of the ommatidia system in both the bands is 2.92 mm. The angle between two neighboring center optical axes of the neighboring ommatidia is 4.016°, with 650 ommatidia, and the combined field of view is 90°.The receiving optical system has a focal length of 4 mm, a field of view of 80° and a relative aperture of 1:3. The ommatidia system and receiving system show good image quality, without any thermal effects in the temperature range of -40℃ to 60℃. ? 2020, Science Press. All right reserved.Accession Number: 20201508406616 -
Record 364 of
Title:Experimental Investigation of Power-Scaled Dissipative Soliton Generation
Author(s):Lv, Zhiguo(1); Yang, Zhi(1); Li, Feng(1); Li, Qianglong(1); Yang, Xiaojun(1); Wang, Yishan(1); Zhao, Wei(1)Source: Frontiers in Physics Volume: 8 Issue: DOI: 10.3389/fphy.2020.00048 Published: March 20, 2020Abstract:We conduct a power scaling study for the femtosecond dissipative soliton generation with a 10-μm core diameter, fiber-based, compact-sized, and low-cost all-normal-dispersion laser configuration. Laser performance, in terms of spectra distribution, temporal characteristic, average power, and stability in 8 h, for different filtering bandwidths has been, respectively, investigated. In the experiment, the obtainable highest output power and shortest pulse duration are 4.5 W and 85 fs, respectively. To our best knowledge, this is the shortest pulse duration among the reported all-fiber pumped Watt-level mode-locked fiber lasers. ? Copyright ? 2020 Lv, Yang, Li, Li, Yang, Wang and Zhao.Accession Number: 20233514650438 -
Record 365 of
Title:Development of an In-Situ Laser Machining System Using a Three-Dimensional Galvanometer Scanner
Author(s):Li, Xiao(1,2); Liu, Bin(1,2); Mei, Xuesong(1,2); Wang, Wenjun(1,2); Wang, Xiaodong(1,2); Li, Xun(3)Source: Engineering Volume: 6 Issue: 1 DOI: 10.1016/j.eng.2019.07.024 Published: February 2020Abstract:In this study, a three-dimensional (3D) in-situ laser machining system integrating laser measurement and machining was built using a 3D galvanometer scanner equipped with a side-axis industrial camera. A line structured light measurement model based on a galvanometer scanner was proposed to obtain the 3D information of the workpiece. A height calibration method was proposed to further ensure measurement accuracy, so as to achieve accurate laser focusing. In-situ machining software was developed to realize time-saving and labor-saving 3D laser processing. The feasibility and practicability of this in-situ laser machining system were verified using specific cases. In comparison with the conventional line structured light measurement method, the proposed methods do not require light plane calibration, and do not need additional motion axes for 3D reconstruction; thus they provide technical and cost advantages. The in-situ laser machining system realizes a simple operation process by integrating measurement and machining, which greatly reduces labor and time costs. ? 2020 THE AUTHORSAccession Number: 20195007829418 -
Record 366 of
Title:Realized large field of view infrared imaging system of single lens with external field splicing
Author(s):Shan, Qiusha(1,2); Su, Xiuqin(1); Duan, Jing(1,2); Zhou, Liang(1); Liu, Kai(1); Yan, Peipei(1); Jiang, Kai(1)Source: Hongwai yu Jiguang Gongcheng/Infrared and Laser Engineering Volume: 49 Issue: 3 DOI: 10.3788/IRLA202049.0314002 Published: March 25, 2020Abstract:Based on the principle of external field splicing, a principle prototype of large-field mid-wave infrared was developed. A cooled mid-wave infrared optical system was designed. The secondary imaging structure of the optical exit aperture coincides with the cold screen was adopted to make sure 100% cold shielding efficiency of the system. The working wave band was 3.7-4.8 μm, the focus was 40 mm, the relative aperture was 1:2, the full field of view was 21.74°×17.46°(27.88°), the total length of the system was 145 mm. The principle of external field splicing with time-sharing exposure imaging of holes/mirrors was adopted, 2×1 field of view expansion was realized. The design result show that MTF>0.68 of the off-axis field of view at spatial frequency of 21 lp/mm, which closes to the diffraction limited. The system has compact constructure and has high imaging quality. The feasibility and rationality of the splicing principle were verified using prototype. ? 2020, Editorial Board of Journal of Infrared and Laser Engineering. All right reserved.Accession Number: 20201808589188 -
Record 367 of
Title:Quantum efficiency of transmission-mode graded bandgap AlxGa1-xAs/GaAs photocathode
Author(s):Yang, Yang(1); Cao, Weiwei(1); Xu, Peng(1); Bai, Yonglin(1); Zhu, Bingli(1); Wang, Bo(1); Qin, Junjun(1); Bai, Xiaohong(1)Source: Journal of Physics: Conference Series Volume: 1676 Issue: 1 DOI: 10.1088/1742-6596/1676/1/012220 Published: November 18, 2020Abstract:Graded bandgap AlxGa1-xAs/GaAs photocathode with enhanced quantum efficiency is analyzed in this study. We present the relevant quantum efficiency equations by solving onedimensional continuity equations for transmission-mode graded bandgap AlxGa1-xAs/GaAs and standard AlGaAs/GaAs photocathodes. The results show that the built-in electrical field from bandgap gradation efficiently collects photogenerated electrons in the buffer layer such that quantum efficiencies in the short regions are improved in transmission-mode AlxGa1-xAs/GaAs photocathode. The results also show that a thinner buffer layer improves the short-wavelength response of transmission-mode photocathode. Increasing the active layer thickness improves long-wavelength responses but reduces short-wavelength responses. The method presented in this work may provide better estimate of performance and guide the optimum design of graded bandgap AlxGa1-xAs/GaAs photocathode. ? Published under licence by IOP Publishing Ltd.Accession Number: 20204909581269 -
Record 368 of
Title:Optical design of portable Raman spectrometer based on-site rapid detection
Author(s):Luo, Weibo(1,2); Yang, Jianfeng(1)Source: Proceedings of SPIE - The International Society for Optical Engineering Volume: 11606 Issue: DOI: 10.1117/12.2585551 Published: 2020Abstract:Raman spectroscopy is used to detect material structure, which is currently one of the fastest growing frontiers in the field of spectroscopy. The detection speed of Raman spectroscopy is very fast and does not require sample preparation, so non-destructive detection can be achieved. The realization of portable Raman spectrometer enables Raman spectroscopy to be used for on-site detection. The portable Raman spectrometer is easy to operate. Moreover, the price is relatively cheap, and the application demand in various industries has become greater. We design a portable Raman spectrometer optical system based on on-site rapid detection. It provides a important foundation for the development and production of portable Raman spectrometers. ? 2020 SPIE.Accession Number: 20210109716225 -
Record 369 of
Title:Luminous Properties of near Infrared Excited Upconversion Luminescent Materials Based on NaYF4
Author(s):Li, Dong-Dong(1); Yang, Tian(1); Ma, Xin-Yu(1); Han, Dong-Dong(1); She, Jiang-Bo(2)Source: Guangzi Xuebao/Acta Photonica Sinica Volume: 49 Issue: 7 DOI: 10.3788/gzxb20204907.0716001 Published: July 1, 2020Abstract:NaYF4:Yb3+/Tb3+and NaYF4:Yb3+/Tm3+double doping fluoride nanomaterials with different doping concentrations were prepared by hydrothermal synthesis. In these materials, the Yb3+ was used as sensitizer to assist in luminous, Tb3+ and Tm3+ were added to the matrix sodium yttrium fluoride as activators of luminous center. The morphology and luminous properties of NaYF4:Yb3+/Tb3+ and NaYF4:Yb3+/Tm3+ nanoparticles were investigated by scanning electron microscope (SEM), X-ray diffraction andfluorescence spectrum. The X-ray diffraction patterns of the series of samples well match the NaYF4 standard card. Upconversion luminescence spectra of materials under 980 nm laser excitation were obtained and the mechanism was also analyzed. Excited by 980 nm laser, the emission spectra of NaYF4:Yb3+/Tb3+ including blue, green and red light, which correspond to the radiative transition of 5D4→7F6, 5D4→7F5, 5D4→7F1, respectively. The strong 480 nm emission can be seen in NaYF4:Yb3+/Tm3+ excited by 980 nm laser, corresponding to the electron transition energy band of 1G4→3H6. A strong red light emission band centered at 660 nm is corresponding to the 1G4→3F4 energy level transition. ? 2020, Science Press. All right reserved.Accession Number: 20203309050402 -
Record 370 of
Title:Generation of controllable chiral optical fields by vector beams
Author(s):Li, Manman(1); Yan, Shaohui(1); Zhang, Yanan(1); Yao, Baoli(1,2)Source: Nanoscale Volume: 12 Issue: 28 DOI: 10.1039/d0nr02693j Published: July 28, 2020Abstract:Chirality is common in nature, describing not only the geometrical property of a three-dimensional object, but also an intrinsic feature of an optical field. Chiral optical fields are attracting increasing attention due to their potential applications in chiral light-matter interaction. Here we demonstrate a strategy to realize a controllable chiral optical field by tightly focusing two tailored vector beams in a 4π optical microscopic system. By modulating the wavefronts of the incident vector beams with appropriately designed phase masks, a chiral optical field with multiple spots carrying switchable handedness or controllable chirality can be generated. The location, the number and the handedness of such chiral spots can be arbitrarily adjusted depending on the actual application requirements. In addition to trapping and manipulating multiple particles, this controllable chiral optical field may find applications in enantioselective separation, chiral detection and chiral sensing at the nanoscale. ? The Royal Society of Chemistry.Accession Number: 20204409430437 -
Record 371 of
Title:Numerical simulation of multiple-current-pulse dielectric barrier discharge with ring electrodes in helium at atmospheric pressure
Author(s):Wang, Jing(1,2); Lei, Bingying(1,2); Li, Jing(1,2); Xu, Yonggang(3); Wang, Yishan(1,2); Tang, Jie(1,2); Zhao, Wei(1,2); Duan, Yixiang(1)Source: Physics of Plasmas Volume: 27 Issue: 4 DOI: 10.1063/1.5135973 Published: April 1, 2020Abstract:A two-dimensional fluid model was used to investigate the characteristics of a multiple-current-pulse dielectric barrier discharge (DBD) equipped with ring electrodes in helium at atmospheric pressure. The simulation results show that the discharge at peak moment follows the Townsend mode in the DBD with two current pulses in each half cycle. However, when there are three or four current pulses in each half cycle, the discharge mode at the first current peak transforms to the glow mode. Additionally, for the first and third current pulse, the breakdown first occurs in the radial center of the ring electrodes. But for the discharge in the second and fourth current pulse, it ignites from the periphery of the ring electrodes. Moreover, the discharge structure, i.e., the radial spatial distributions of current density, electron density, and electric field at peak moments, shows a feature of alternation between (1) higher current density, electron density, and electric field locating in the radial center of ring electrodes (center-advantage) and (2) higher current density, electron density, and electric field locating in the periphery of ring electrodes (periphery-advantage). This behavior is attributed to the fact that non-uniform surface charge accumulation during the previous discharge has different effects on the electric field in the gas gap in the subsequent discharge. ? 2020 Author(s).Accession Number: 20201608418619 -
Record 372 of
Title:3D waveguide element fabrication in Gorilla glass by an ultrafast laser
Author(s):Lv, Jing(1,2,3,4,5); Wang, Kedian(1,3,4); Cheng, Guanghua(2,5)Source: Applied Optics Volume: 59 Issue: 27 DOI: 10.1364/AO.401341 Published: September 20, 2020Abstract:Waveguide fabrication with an ultrafast laser system and the mechanism of index modification have been investigated in Corning Gorilla glass. Type I waveguides were obtained when the pulse duration was in the range of 250 fs to 15 ps. With the increase of pulse energy, single-mode waveguides converted to ring-mode waveguides. The variation tendency of Raman peak at 580 cm?1 band is nonmonotonic with the increase of pulse energy, and the negative index change appears finally in the waveguide core. The alkali ions migrated towards the outside with different diffusivities after the laser irradiation. Finally, bend waveguides and hexagon-link waveguide connectors were produced. ? 2020 Optical Society of AmericaAccession Number: 20204109322302