2022
2022
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Record 433 of
Title:Graphene/Epoxy Composite Based Broadband All-Optical Tunable Fiber Microcavity Filter
Author(s):Li, Yang(1,2,3); Dong, Bo(4); Chen, Enqing(3); Wang, Xiaoli(3); Li, Ziwan(3); Zhao, Yudi(3); Zhao, Wei(2,5); Wang, Yishan(2)Source: Journal of Lightwave Technology Volume: 40 Issue: 4 DOI: 10.1109/JLT.2021.3125189 Published: February 15, 2022Abstract:A graphene/epoxy composite based broadband all-optical tunable fiber microcavity filter is presented. The graphene/epoxy composite based microcavity shows the excellent all-optical controlability. Since the light acts on the graphene/epoxy composite directly, the microcavity has stronger optical Kerr effect and photothermal effect induced by the optical pump. Experimental results show that its wavelength tuning range and tuning step reach 25.54 nm and -832 pm/mW, respectively. It is expected to be applied in the fields of tunable optical filters, optical communication, optical sensors, fiber lasers, and spectrum scanning. ? 1983-2012 IEEE.Accession Number: 20214511139695 -
Record 434 of
Title:Ultra-broadband flat-top circular polarizer based on chiral fiber gratings near the dispersion turning point
Author(s):Ren, Kaili(1,2); Yao, Kexin(1); Han, Dongdong(1); Hu, Jiayue(1); Yang, Li(3); Zheng, Yipeng(1); Liang, Lei(1); Dong, Jun(1); Zhang, Wenfei(2,4); Ren, Liyong(2,5)Source: Optics Express Volume: 30 Issue: 23 DOI: 10.1364/OE.473233 Published: November 7, 2022Abstract:Based on the dual-resonance principle around the dispersion turning point, a scheme of chiral long-period fiber gratings (CLPGs) formed by twisting a high-birefringence (Hi-Bi) fiber is herein proposed to realise ultra-broadband flat-top circular polarizers. The coupling bandwidth is approximately seven times larger than that of traditional CLPGs. In addition, by introducing chirp characteristics in these CLPGs, an ultra-broadband flat-top circular polarizer with ～200 nm@3 dB was conveniently achieved. Subsequently, by optimising the chirped CLPGs, a circular polarizer with a bandwidth extinction ratio of approximately 30 dB and a high level of ～100 nm at 1 dB was realised. It was shown that the mode-controlling performances of the CLPGs can be remarkably improved, which has significant applications in light-field regulation. Finally, for the first time, it was proved that the CLPG cannot generate a vortex beam. ? 2022 Optica Publishing Group.Accession Number: 20224613096930 -
Record 435 of
Title:High-performance plasmonic sensor based on photonic crystal fiber for refractive index and temperature sensing
Author(s):Meng, Xiaojian(1); Zhao, Yuanyuan(1); Li, Jianshe(1); Guo, Ying(1); Li, Shuguang(1); Guo, Haitao(2); Du, Huijing(1); Li, Zenghui(1); Li, Mengqiang(1); Feng, Yuhui(1); Wang, Luyao(1); Wang, Xiaokai(1)Source: Infrared Physics and Technology Volume: 122 Issue: DOI: 10.1016/j.infrared.2022.104036 Published: May 2022Abstract:In this paper, a refractive index and temperature plasmonic sensor based on photonic crystal fiber is proposed. In order to achieve the best performance, a serial of study on the theory and experimental steps is carried out, including simulation calculation, detection system, coating method and chemical etch technology. Experimental results demonstrate that a high average sensitivity of 3381 nm/RIU within a linear refractive index ranging from 1.3333 to 1.3860 can be achieved, which is greater than the traditional fiber structure. In addition, this sensor is helpful to measure temperature change and the sensitivity could be 2 nm/°C. Due to its easy and controllable fabrication, the proposed sensor has great application prospects in the field of optical device. ? 2022Accession Number: 20220811677598 -
Record 436 of
Title:A compact killowatt-level QCW high-power semiconductor laser array based on dual-chip integration
Author(s):Zhang, Pu(1,2,3); Ren, Wenzhen(2); Wang, Bo(2,3); Zhu, Xiangping(1,2); Yang, Junhong(1)Source: Proceedings of SPIE - The International Society for Optical Engineering Volume: 12311 Issue: DOI: 10.1117/12.2643908 Published: 2022Abstract:With the increase of output power, more heat generation and higher operation current have become important issues, which affect the electrical-optical performance and reliability of high power semiconductor lasers. For the past several years, high power semiconductor laser chips utilizing double or triple quantum wells have been developed to achieve higher output power. However, the operation current of diode laser chips with double or triple quantum wells is much higher than that with single quantum well. Diode laser chips with double or triple quantum wells could only operate at a much lower duty cycle. In this paper, a compact quasi-continuous wave (QCW) high power semiconductor laser array based on dual-chip integration techniques has been developed. For this packaging structure, two diode laser bars were welded above and below a micro-channel heat sink, without significant increase in volume. By means of this integration method, the output power of the semiconductor laser could reach kilowatt-level at a lower operation current. The thermal behavior of the semiconductor laser array with different operation parameters was carried out using finite element method. The structure parameters of semiconductor laser array based on dual-chip integration were optimized and characterized. The output power is 1485 W operated at a current of 700 A and the maximum electro-optical efficiency is 75%, which is the record-high level for a high power semiconductor laser array. ? 2022 SPIE.Accession Number: 20230413424266 -
Record 437 of
Title:Arbitrary Modulation of Airy Vortex Beam in Multi-spatial Dimensions
Author(s):Wang, Yakun(1); Tai, Yuping(2); Li, Xinzhong(1,3)Source: Guangzi Xuebao/Acta Photonica Sinica Volume: 51 Issue: 1 DOI: 10.3788/gzxb20225101.0151116 Published: January 25, 2022Abstract:As a composite optical field, Airy vortex beam possessing transverse and longitudinal superimposed modes has abundant intensity and phase distributions. However, the composite optical field is limited to the specific propagation direction and complex modulation of the propagation trajectory. To address these issues, based on the multicoordinate transformations, one-dimensional Airy beam, two-dimensional Airy beam and Airy vortex beam have been transformed in different coordinate systems, respectively. We have realized the orientation modulation of the two lobes of Airy beam and the embedded optical vortex in the range of 0-2π, independently. We have studied the propagation properties in the propagation distances of 0, 2, 6, and 10 cm in the case of the obtuse and acute angles between two lobes of the Airy beam and the Airy vortex beam with orthogonal lobes, respectively. The results of experiments and numerical simulations show that the generated optical field can propagate along arbitrarily appointed parabolic trajectories and directions in free space. In addition, a method for measuring topological charge is proposed by adding the shift factor d when the directions of the lobes are opposite. This proposed method enables in situ determination of the embedded optical vortexes' topological charge without the need for additional optical elements, and it is immune to environmental vibration and parasitic interference. Our results promote the applications of Airy vortex beam in particle manipulation and optical cleaning and provide an alternative scheme for the modulation of composite optical field.Measurement of the topological charge and the intensity profiles at different propagation distance via the experimental setup. ? 2022, Science Press. All right reserved.Accession Number: 20220711635224 -
Record 438 of
Title:Thin Piezoelectric Sheet Assisted PGC Demodulation of Fiber-Optic Integrated MZI and its Application in under Mattress Vital Signs Monitoring
Author(s):Xu, Wei(1); Yu, Changyuan(2); Dong, Bo(3); Wang, Yishan(4); Zhao, Wei(4)Source: IEEE Sensors Journal Volume: 22 Issue: 3 DOI: 10.1109/JSEN.2021.3128601 Published: February 1, 2022Abstract:A modified solid fiber-optic integrated Mach-Zehnder interferometer (IMZI) assisted with a thin piezoelectric sheet (TPS, 130 μ m thickness) and phase generated carrier (PGC) demodulation is proposed and investigated theoretically and experimentally. The IMZI's two arms are respectively molded with epoxy resin (EP) and silicone rubber (SI). These two materials are with distinctly different elastic modulus and Poisson ratios, which guarantees the high sensitivity of the IMZI. As for PGC, different modulation frequencies and amplitudes are generated and the corresponding modulation depths are calculated to obtain the optimal modulating parameters. Furthermore, a pair of complementary photodetectors are used to remove unwanted DC component and only the first harmonic is utilized to recover the phase, which can effectively avoid signal fading. In the experiments, where the IMZI is put under the mattress, activity monitoring is addressed and subjects are recruited to investigate the vital signs monitoring performance. The consistency check analysis results show the calculated heart rate variability (HRV) and breath rate variability (BRV) results are highly correlated with reference results, and the Pearson's r reaches 0.99. Moreover, reliability, post-exercise, and Valsalva Maneuver test are further conducted to verify the repeatability and dynamic monitoring capability. In conclusion, the proposed system is unobtrusive, cost-effective, robust, and convenient, which has great potential in future homecare and hospitalization. ? 2001-2012 IEEE.Accession Number: 20215211398738 -
Record 439 of
Title:Experimental demonstration of an improved control design and algorithm for optical communication terminal with disturbance
Author(s):Guo, Huinan(1)Source: Optik Volume: 269 Issue: DOI: 10.1016/j.ijleo.2022.169939 Published: November 2022Abstract:Objective: Vibration interference causes the misalignment between the incident beam and the optical axis of the opto-mechanical terminal system, which also can significantly affect the control stability and reduce the system precision. To better improve the resilience of disturbance and the steady-state accuracy, Methods: a novel robustness servo design and disturbance rejection algorithm with iterative learning control for tracking error calibration is proposed. The availability of this system design has been proved from a dynamic tracking experiment, the operating modes are based on different disturbance conditions. Result: The experiment itself focused on the algorithm implementation and tracking stability based on the optical communication terminal assembly. The obtained steady-state response performance during the adjustment process indicates that the tracking errors are below 1.3 μrad. The improved control design and algorithm implementation shows a better disturbance rejection ability. The new approach is also beneficial for the optical communication field. ? 2022 The AuthorsAccession Number: 20223712704774 -
Record 440 of
Title:Measurement for far-field focal spot of high power laser based on the diffraction inversion of sidelobe beam
Author(s):Wang, Zhengzhou(1); Wang, Li(1); Wei, Jitong(1); Wang, Wei(1); Li, Gang(1); Yi, Dongchi(1); Wang, Yajun(1)Source: Guangxue Jingmi Gongcheng/Optics and Precision Engineering Volume: 30 Issue: 4 DOI: 10.37188/OPE.20223004.0380 Published: February 25, 2022Abstract:In order to solve the problem that the schlieren method cannot accurately measure the weak signal region of the sidelobe beam in large laser devices of the national large scientific facility, a new schlieren method based on the diffraction inversion of the sidelobe beam is proposed to measure the far-field focal spot for high-power laser. The key point of this method is that an indirect measurement approach is used based on reverse deduction, while deducting along the reverse direction of the optical path propagation. The diffraction intensity image and phase image of the sidelobe beam are the inputs to calculate the far-field focal spot distribution of the front sidelobe beam, which is not shielded. Compared with the traditional far-field focal spot measurement based on the schlieren method, the improvements and optimizations proposed in this paper are as follows. First, the mathematical model of far-field focal spot measurement using the schlieren method is improved to reveal the rationality of the model, theoretically based on the principle of diffraction inversion of the sidelobe beam and the indirect measurement approach. Then, the feasibility of this method is verified by simulating the whole experimental process of high power laser far-field focal spot measurement, which consists of sidelobe beam diffraction, denoising, sidelobe beam diffraction inversion, and focal spot reconstruction. Finally, the improved DnCNN algorithm is used to remove the noise of different levels (0-75 dB) of 12 bit scientific CCD images in the mainlobe and sidelobe beams, and the reconstruction accuracy of far-field focal spot is improved. The experimental results show that this method not only eliminates the influence of the schlieren sphere on the diffraction of the sidelobe beam but also obtains the real intensity distribution of the sidelobe beam in the weak signal region, including the important parameters of far-field focal spot measurement, such as the amplitude and position of each peak of the side lobe beam, the dynamic range ratio, the amplitude and position of each peak of the sidelobe beam, and the ratio of dynamic range. The error between the reconstructed and theoretical focal spots of the dynamic range ratio is 3.20%. It is significant to improve the reliability and experimental accuracy of the far-field focal spot of high-power laser measurement using the schlieren method. ? 2022, Science Press. All right reserved.Accession Number: 20221411918831 -
Record 441 of
Title:Numerical simulation of coaxial-coplanar dielectric-barrier discharge in atmospheric helium
Author(s):Ran, Shuang(1,2); Wang, Jing(1,2); Lei, Bingying(1,2); Liu, Simeng(1,2); Li, Jing(3); Wang, Yishan(1,2); Zhao, Wei(1,2); Duan, Yixiang(4); Tang, Jie(1,2)Source: AIP Advances Volume: 12 Issue: 5 DOI: 10.1063/5.0089080 Published: May 1, 2022Abstract:A self-consistent two-dimensional fluid model is employed to investigate the coaxial-coplanar dielectric-barrier discharge (DBD) excited by the sinusoidal voltage in atmospheric helium. Simulation results show that there are two current pulses in the positive half cycle, but only one in the negative half cycle. The discharge is transformed from the Townsend-like mode, through the glow-like mode, and back to the Townsend-like mode in both the positive and negative half cycles, during which the electric field line exhibits an arc-shape profile due to the configuration of coaxial-coplanar electrodes. In the glow-like mode, the cathode fall is located near the inner edge of the ground electrode at the first positive current peak, but close to the outer edge of the ground electrode at the second positive current peak. At the negative current peak, the cathode fall is distributed near the outer edge of the high voltage electrode. Since the instantaneous anode and the instantaneous cathode are on the same side of the discharge space, the dielectric layer is simultaneously covered by positive and negative surface charges due to the movement of charged particles. It is also found that the surface charge density changes significantly on the dielectric layer facing the electrodes. A further study reveals that a stronger discharge always occurs in the central circular area and an alternately complementary discharge takes place in the periphery ring area in the positive half cycle due to the activator-inhibitor effect. This feature is helpful for producing uniform plasma in a whole cycle of DBD. ? 2022 Author(s).Accession Number: 20222012113424 -
Record 442 of
Title:Alleviation of honeycomb print-through of NiP/Cu coated carbon fiber composite mirror via robot-arm wheel polishing
Author(s):Wang, Yong-jie(1); Yao, Yong-sheng(1); Xu, Liang(1); Wu, Xiao-ge(1); Shen, Le(1); sun, Guo-yan(1)Source: Materials Chemistry and Physics Volume: 283 Issue: DOI: 10.1016/j.matchemphys.2022.126028 Published: May 1, 2022Abstract:In order to realize higher lightweight rate, CFRP (Carbon Fiber Reinforced Polymer) composites were applied to fabricate mirror. A NiP coating was prepared on the surface, meanwhile honeycomb print through was discussed in the paper. Before NiP alloy coating plating, a Cu film was prepared through magnetron sputtering to reinforce the adherence with CFRP mirror. The NiP coating contained 10.9% P and exhibited an amorphous structure. Obvious "honeycomb print-through" was found in the classical polish, the final surface accuracy was just 0.048λ (RMS, λ = 632.8 nm). However, the print-through can be alleviated through Robot-arm wheel polishing. 0.015λ (RMS) of surface accuracy was realized on a Ф100mm CFRP mirror. ? 2022Accession Number: 20221311851072 -
Record 443 of
Title:Mid-infrared optical parametric oscillation spanning 3.4-8.2 μm in a MgF2microresonator
Author(s):Sun, Qibing(1,2); Wu, Wei(1,2); Wang, Yi(1,2); Yang, Yu(3); Shi, Lei(1,2); Ming, Xianshun(1); Wang, Leiran(1,2); Wang, Keyi(3); Zhao, Wei(1,2); Zhang, Wenfu(1,2)Source: Nanotechnology Volume: 33 Issue: 21 DOI: 10.1088/1361-6528/ac52bf Published: May 21, 2022Abstract:Mid-infrared optical parametric oscillators (OPOs) offer a compelling route for accessing the 'molecular fingerprint' region and, thus, can find intensive applications such as precision spectroscopy and trace gas detection. Yet it still remains rather a challenge to realize broadband mid-infrared OPOs within a single cavity, usually limited by strict phase-matching conditions for wide spectral coverage and available pump power for adequate frequency generation. Here, we report the mid-infrared parametric oscillation spanning from 3.4 to 8.2 μm, based on four-wave mixing in a high-Q MgF2 microresonator with optimized dispersion. The center wavelength at 4.78 μm is determined by the continuous tunable quantum cascade laser source, which contributes to effective expansion towards longer wavelength, as well as systemic miniaturization with smaller pump module. Such results could not only shed light on new ultimates of crystal and other microresonators, but also inspire explorations on their growing potentials in near future. ? 2022 IOP Publishing Ltd.Accession Number: 20221311832940 -
Record 444 of
Title:Light modulation based on the enhanced Kerr effect in molybdenum disulfide nanostructures with curved features
Author(s):Li, Tianlun(1); Li, Xiaodie(1); Gao, Duorui(2,3); Mao, Jianyong(1); Hou, Yaping(1); Chen, Hui(1); Li, Feng(1); Zhang, Yanpeng(1); Fang, Jixiang(1); Zhang, Lei(1)Source: Physical Chemistry Chemical Physics Volume: 24 Issue: 20 DOI: 10.1039/d2cp00374k Published: May 2, 2022Abstract:A novel type of molybdenum disulfide (MoS2) nanoparticles (NPs) was chemically synthesized, which possessed curved features with three-dimensional (3D) freedom compared with planar two-dimensional (2D) materials. Due to the introduction of curved features, the synthesized NPs exhibited a strongly enhanced nonlinear refractive index (n2 ～ 10?5 cm?2 W?1) and third-order susceptibility (χ(3) ～ 10?7 esu), which were experimentally verified by the spatial self-phase modulation effect in the visible wavelength range. Both the nonlinear parameters were two orders of magnitude higher than their planar MoS2 nanostructure counterparts. In addition, the relative change of the effective nonlinear refractive index Δn2/n2 was found to be distinctly dependent on the intensity of the applied electromagnetic field. Moreover, an all-optical modulation was experimentally realized based on the spatial cross-phase modulation effect. Our results demonstrate planar MoS2 materials with 3D features as potential candidates for next generation all-optical applications and open a substantial approach for the design of efficient nanomaterials with favorable optical nonlinearity. ? 2022 The Royal Society of ChemistryAccession Number: 20222412207450