2023

• Record 385 of
  
  Title:Effect of introducing KNO3 on the preparation of athermal fluorophosphate glass and investigation on its thermo-optical property
  
  Author(s):Gao, Fei(1,2,3); Zhang, Faqiang(1,3); Yang, Liqing(1); Ma, Zhiyuan(4); Yang, Feng(4); Hu, Bin(1,4); Peng, Bo(1); Liu, Chunliang(2); Wang, Pengfei(1,3)
  Source: Optical Materials  Volume: 145  Issue: null  Article Number: 114415  DOI: 10.1016/j.optmat.2023.114415  Published: November 2023  
  Abstract:The effects of introducing some amount of KNO3 into the raw materials on preparation of fluorophosphate glass are investigated in terms of UV–vis transmittance, absorption coefficient and change of refractive index. As the content of KNO3 reaches 50%, the UV absorption coefficient of the optimized fluorophosphate glass reaches the minimum due to absence of microcrystals in the produced glass. The Schott's Sellmeier dispersion formula and Ghosh's two-polar wavelength-dependent Sellmeier equation were both used to calculate dispersion constants of the optimized fluorophosphate glass. The optimized fluorophosphate glass maintains special characteristics of negative temperature coefficient of refractive index and near-zero thermo-optical coefficient. The lower absorption both in UV and near-infrared (NIR) helps to improve its laser-induced damage resistance. The athermal fluorophosphate glass shows great potential for compensation of thermal-induced distortion in high-power solid-state lasers and high-resolution optical systems. © 2023 Elsevier B.V.
  Accession Number: 20234114874732
• Record 386 of
  
  Title:Dynamically switchable broadband–narrowband terahertz metamaterial absorber based on vanadium dioxide and multilayered structure
  
  Author(s):Wen, Jin(1,2); Sun, Wei(1); Liang, Bozhi(1); He, Chenyao(1); Xiong, Keyu(1); Wu, Zhengwei(1); Zhang, Hui(1); Yu, Huimin(1); Wang, Qian(1); Pan, Yu(1); Zhang, Ying(1); Liu, Zhanzhi(1)
  Source: Optics Communications  Volume: 545  Issue: null  Article Number: 129710  DOI: 10.1016/j.optcom.2023.129710  Published: October 15, 2023  
  Abstract:We propose and demonstrate a terahertz metamaterial absorber based on vanadium dioxide (VO2) and multilayered structure with dynamically switchable broadband and narrowband absorption. Its main structure is a double absorption layer composed of VO2 rings and gold pattern. Through adjusting the conductivity of VO2, the absorber can actively transform between broadband absorption of greater than 90% in the frequency range of 2.6 THz to 6.28 THz and narrowband absorption of greater than 99.9% at 7.77 THz. A particular explanation of physical absorption mechanism based on electromagnetic resonance is presented by electromagnetic field distributions and the impedance matching theory. Furthermore, the influence of the absorption layer patterns and structural parameters on the absorber performance cannot be ignored. This absorber structure also has the features of polarization insensitivity and incident wide-angle admissibility. Compared with recent studies, the absorber has improved in absorption bandwidth with the simpler design in the number of layer. The proposed absorber may find some important applications in the modulation, sensing and imaging fields. © 2023 Elsevier B.V.
  Accession Number: 20232814378601
• Record 387 of
  
  Title:All-optical spiking neural network and optical spike-time-dependent plasticity based on the self-pulsing effect within a micro-ring resonator
  
  Author(s):Wen, Jin(1,2); Zhang, Hui(1); Wu, Zhengwei(1); Wang, Qian(1); Yu, Huimin(1); Sun, Wei(1); Liang, Bozhi(1); He, Chenyao(1); Xiong, Keyu(1); Pan, Yu(1); Zhang, Ying(1); Liu, Zhanzhi(1)
  Source: Applied Optics  Volume: 62  Issue: 20  Article Number: null  DOI: 10.1364/AO.493466  Published: July 2023  
  Abstract:In this paper, we proposed an all-optical version of photonic spiking neurons and spike-time-dependent plasticity (STDP) based on the nonlinear optical effects within a micro-ring resonator. In this system, the self-pulsing effect was exploited to implement threshold control, and the equivalent pulse energy required for spiking, calculated by multiplying the input pulse power amplitude with its duration, was about 14.1 pJ. The positive performance of the neurons in the excitability and cascadability tests validated the feasibility of this scheme. Furthermore, two simulations were performed to demonstrate that such an all-optical spiking neural network incorporated with STDP could run stably on a stochastic topology. The essence of such an all-optical spiking neural network is a nonlinear spiking dynamical system that combines the advantages of photonics and spiking neural networks (SNNs), promising access to the high speed and lower consumption inherent to optical systems. © 2023 Optica Publishing Group.
  Accession Number: 20233214487975
• Record 388 of
  
  Title:Ultrafast optical gated image intensifier with a temporal resolution of 230 picosecond using uniform underlayer
  
  Author(s):Yang, Yang(1,2); Gou, Yongsheng(1,2); Feng, Penghui(1,4); Wang, Bo(2); Liu, Baiyu(1); Tian, Jinshou(1,3); Wang, Xu(1); Liu, Hengbo(1)
  Source: Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment  Volume: 1056  Issue: null  Article Number: 168621  DOI: 10.1016/j.nima.2023.168621  Published: November 2023  
  Abstract:An Au uniform photocathode underlayer is employed in this paper to obtain picosecond (ps) optical gating width for image intensifier tube. The transmittances and gating pulse transmission efficiencies of the underlayer with different thicknesses are tested and compared to determine the optimal thickness. An 18 mm diameter proximity focused microchannel plate image intensifier tube with S25 photocathode is fabricated using this uniform underlayer. The profile measurement shows the tube has an optical gating time as low as 230 ps full width at half maximum (FWHM) when gated with a 176 ps width gating pulse. The measured iris delay is between 83 ps and 108 ps, which approaches the theoretical limit of its kind. © 2023 Elsevier B.V.
  Accession Number: 20234014817735
• Record 389 of
  
  Title:Radiation force of a special correlated beam with off-axis multiple vortices on Rayleigh particles
  
  Author(s):Zhou, Zheng-lan(1); Zhang, Shao-hua(1); Zhou, Yuan(2); Han, Ya-shuai(1); Zhou, Zheng-xian(1); Yao, Bao-li(2); Qu, Jun(1)
  Source: Journal of Quantitative Spectroscopy and Radiative Transfer  Volume: 302  Issue: null  Article Number: 108580  DOI: 10.1016/j.jqsrt.2023.108580  Published: July 2023  
  Abstract:In order to explore the potential application of a superimposed Hermite-Gaussian correlated Schell-model beams with off-axis multi-vortices in optical trapping, based on the generalized Collins formula, the focused beam intensity and radiation force on particles are derived in detail. Numerical results show that the gradient force and capture stability range increase with the increase of topological charge. By changing the vortex off-axis distance, the precise position control of the particles can be made. Adjusting the number of vortices can control the existence of vortex singularity on the side lobe of the beam, and generate or close the optical potential well or optical cage in real time. By selecting the appropriate beam order, two kinds of particles with different refractive indexes can be captured. The beams are expected to be applied to optical trapping of multiple particles at different positions. © 2023
  Accession Number: 20231213778010
• Record 390 of
  
  Title:Sideband suppression of conventional soliton in Figure-9 passively Mode-locked fiber laser
  
  Author(s):Liang, Lei(1); YijieWang(1); Hu, Qianyu(1); Ren, Kaili(1,2); Zheng, Yipeng(1); Zhu, Lipeng(1); Li, Lu(1); Han, Dongdong(1)
  Source: Infrared Physics and Technology  Volume: 131  Issue: null  Article Number: 104688  DOI: 10.1016/j.infrared.2023.104688  Published: June 2023  
  Abstract:In this paper, the sideband suppression of a conventional soliton pulse is studied experimentally and theoretically based on a figure-9 passively mode-locked fiber laser. The sidebands of a conventional soliton could be suppressed by adjusting the polarization controller without reducing the output power of the soliton pulse. Three typical spectral forms with different degrees of sidebands suppression are experimentally obtained and the mechanism is analyzed theoretically. Based on the round-trip model, a theoretical model of a figure-9 passively mode-locked fiber laser is established. By changing the phase difference induced by polarization controller in the laser cavity, the experimental results could be confirmed. The above results have important reference value for improving the conventional soliton spectral output and eliminating the conventional soliton sidebands. © 2023 Elsevier B.V.
  Accession Number: 20231613889034
• Record 391 of
  
  Title:Large dispersion-managed broadband high-energy fiber femtosecond laser system with sub 300 fs pulses and high beam quality output
  
  Author(s):Li, Feng(1); Zhao, Wei(1); Wang, Yishan(1); Li, Dongjuan(1); Song, Dongdong(1); Li, Qianglong(1); Yang, Yang(1); Wen, Wenlong(1)
  Source: Optics and Laser Technology  Volume: 157  Issue: null  Article Number: 108653  DOI: 10.1016/j.optlastec.2022.108653  Published: January 2023  
  Abstract:We experimentally demonstrate a high-energy sub 300 fs polarization maintaining fiber chirped pulse amplification (CPA) system. The preamplifier is a monolithic fiberized system that uses two cascaded temperature-assisted dispersion-tuning broadband chirped fiber Bragg gratings (CFBGs) with a reflected bandwidth of 20 nm as stretchers. To make full use of the stretcher to lower the system's nonlinearity accumulation, a homemade mode locked fiber laser with a spectral width of 14.8 nm (full width at half maximum) is selected as the seeder to offer a stretched pulse width of 1.69 ns. The main amplifier is based on a one-stage simple Yb:YAG single crystal fiber amplifier with an amplified output power of 40.6 W at a repetition rate of 200 kHz, and the beam quality is conserved in a single mode beam profile with beam quality of 1.246 and 1.142 in the horizontal direction and vertical direction, respectively. During amplification, the spectral gain narrowing effect is observed. To achieve the high-speed switch of the laser, an acoustical optical modulator (AOM) is inserted before the compressor to achieve high-speed turn-on/off control. The compressor is based on a diffraction grating pair with a groove density of 1600 line/mm to offer a dispersion match with the stretcher of the CFBGs. With the CFBG's fine-tuned capacity of second-order dispersion and higher-order dispersion, the compressed average power of 29.6 W and pulse duration of 278 fs, corresponding to a pulse energy of 148 µJ and a peak power of 532 MW with ignoring the wings of the pulse, is obtained. The beam quality is well conserved after compression, and the beam quality is 1.250 and 1.196 in the horizontal direction and vertical direction, respectively. A power fluctuation of 0.1% (root mean square) and a beam pointing drift of 8.47 µrad/°C over 8 h are realized. This high peak power and high beam quality femtosecond laser is promising in science and industrial applications. © 2022
  Accession Number: 20223712727226
• Record 392 of
  
  Title:Complete and robust energy conversion by sum frequency generation based on invariant engineering
  
  Author(s):Zhang, Cong-Fu(1,2); Wang, Zhao-Lu(1); Liu, Hong-Jun(1,3)
  Source: Optics Express  Volume: 31  Issue: 3  Article Number: null  DOI: 10.1364/OE.477959  Published: January 30, 2023  
  Abstract:An analytical method is proposed in this paper to achieve complete energy conversion in sum frequency generation based on the Lewis-Riesenfeld invariants theory. In the proposed scheme, a quasi-adiabatic single control parameter model is established, and the value of single control parameter is selected to make the initial eigenstate perfectly converted to the final eigenstate as needed. Corresponding to the nonlinear frequency conversion process, a nonlinear crystal structure is designed by inverse engineering using the optimal control theory. It is robust against perturbations of the coupling coefficient and phase mismatch, including variations in the pump intensity and crystal polarization period, and achieves almost 100% conversion efficiency at any crystal length. Theoretical simulations show that frequency conversion can be achieved in the wavelength range of 2.6 μm-3.6 μm, and the spectral bandwidth of conversion efficiency exceeds 50% and approaches 400 nm when the crystal length L = 1 mm. © 2023 Optica Publishing Group.
  Accession Number: 20230513475061
• Record 393 of
  
  Title:Realizing particle population inversion of 2.7 μm emission in heavy Er3+/Pr3+ co-doped low hydroxyl fluorotellurite glass for mid-infrared laser
  
  Author(s):Feng, Shaohua(1,2); Liu, Chengzhen(1,2); Zhu, Jun(1,2); Xu, Yantao(1,2); Xiao, Xusheng(1,2); Guo, Haitao(1,2,3)
  Source: Ceramics International  Volume: 49  Issue: 12  Article Number: null  DOI: 10.1016/j.ceramint.2023.03.165  Published: June 15, 2023  
  Abstract:In this work, the population bottleneck of Er3+: 4I11/2 → 4I13/2 was overcome for the first time in heavy Er3+/Pr3+ co-doped TeO2–BaF2–La2O3–LaF3 (TBLL) low hydroxyl fluorotellurite glasses. Infrared emission spectra and fluorescence lifetime decay curves reveal that Pr3+ ions could deplete the electrons from the Er3+: 4I13/2 level faster than those from the Er3+: 4I11/2 under 980 nm excitation. Specifically, the energy transfer (ET) efficiency of the Er3+: 4I13/2 → Pr3+: 3F3,4 process (ET1) reached 96.27%, while that of the Er3+: 4I11/2 → Pr3+: 1G4 process (ET2) is only 2.17% in the Er3+/Pr3+ co-doped glass. Additionally, the energy transfer mechanism of Er3+ and Pr3+ ions was investigated using the Dexter theory, where the energy transfer microscopic parameters CD-A are 13.21 × 10−40 cm6/s and 0.89 × 10−40 cm6/s for the ET1 and ET2 processes, respectively. Finally, a numerical simulations laser model was developed to discuss the laser properties of the Er3+/Pr3+ co-doped TBLL fibers. The simulation results indicate that a 2.7 μm laser with a maximum output power of 2.26 W and slope efficiency of 13.89% could be achieved when the fiber background loss is reduced to 0.5 dB/m. The above results suggest that the Er3+/Pr3+ co-doped TBLL glass has great potential applications in mid-infrared fiber lasers. © 2023 Elsevier Ltd and Techna Group S.r.l.
  Accession Number: 20231413846930
• Record 394 of
  
  Title:Phase regeneration of star-16QAM using phase-sensitive amplification in graphene silicon-based organic hybrid waveguide
  
  Author(s):Ren, Li(1); Li, Xuefeng(2); Wu, Xiao(1); Liu, Hongjun(3)
  Source: Optics Communications  Volume: 540  Issue: null  Article Number: 129530  DOI: 10.1016/j.optcom.2023.129530  Published: August 1, 2023  
  Abstract:We theoretically demonstrate the phase regeneration of the star-16-quadrature-amplitude-modulation(star-16QAM) signal in a graphene-graphene oxide hybrid waveguide. The multi-order dispersion properties of this waveguide are tuned by graphene, where the near-zero-dispersion-point moves to right with increasing applied electrochemistry. The waveguide nonlinearity coefficient is 1.534×106/m/W and the dispersion is flat in the ultra-wide wavelength range of 1310 nm to 1860 nm by filling the waveguide with the high kerr coefficient organic material graphene oxide. The phase regeneration of the star-16QAM signal is achieved by using a dual-conjugate-pump degenerate four-wave mixing (FWM) technique, and the results show that the error-vector -magnitude (EVM) is reduced from 39.25% to 2.14%, the phase noise is effectively compressed. © 2023 Elsevier B.V.
  Accession Number: 20231814028077
• Record 395 of
  
  Title:Spectral beam combining of fiber lasers with 32 channels
  
  Author(s):Gao, Qi(1,2); Li, Zhe(1,2); Zhao, Wei(1); Li, Gang(1,2); Ju, Pei(1,2); Gao, Wei(1,2); Dang, Wenjia(3)
  Source: Optical Fiber Technology  Volume: 78  Issue: null  Article Number: 103311  DOI: 10.1016/j.yofte.2023.103311  Published: July 2023  
  Abstract:We present a method for the spectral combination of fiber lasers with high spectral density, increasing spectral density utilization with no degradation in beam quality, and decreasing single channel narrow linewidth output power. Experiments demonstrating the utility of our method are described. The results show that we achieved 32-channel fiber laser spectral beam combining (SBC) with a beam quality of M2 = 1.68. The SBC beam quality can be constantly optimized by integrally varying the spectral interval with the feedback system. Our method offers a point of reference to broadening to additional channels and enhancing the output power of the SBC with an excellent beam quality. © 2023 The Authors
  Accession Number: 20231513877424
• Record 396 of
  
  Title:10-W random fiber laser based on Er/Yb co-doped fiber
  
  Author(s):Li, Zhe(1,2); Gao, Qi(1,2); Li, Gang(1,2); She, Shengfei(1,2); Sun, Chuandong(1); Ju, Pei(1,2); Gao, Wei(1,2); Dang, Wenjia(3)
  Source: Optical Fiber Technology  Volume: 77  Issue: null  Article Number: 103251  DOI: 10.1016/j.yofte.2023.103251  Published: May 2023  
  Abstract:In this study, we presented a 1550-nm, high-power, high-efficiency random fiber laser to improve the output power and slope efficiency of erbium-ytterbium co-doped fiber–based random fiber lasers. By optimizing the length of the erbium-ytterbium co-doped fiber and increasing the 3-dB reflection bandwidth of fiber Bragg grating, the output power and slope efficiency of the random fiber laser were improved. Furthermore, the influence of different fiber lengths on the generation threshold of the amplified spontaneous emission from the Yb3+-ions was studied. An output power of more than 10 W was achieved, with a slope efficiency of 36.7 % and a single transverse mode output. The proposed random fiber laser showed excellent stability in the millisecond scale and long timescale (10 min). The findings of this study can provide a basis for the development of high-performance light sources for a variety of applications. © 2023 The Authors
  Accession Number: 20230613555366