摘要：
以非线性薛定谔方程为理论模型，研究了艾里-高斯光束在高斯型PT（Parity-time）对称介质中的传输与控制。详细分析了高斯型PT对称介质的特征参数（调制深度 P、调制因子 ω、增益/损耗系数W0）和艾里-高斯光束的特征参数（截断系数a、分布因子 χ0）对艾里-高斯光束的传输特性的影响。结果表明：在高斯型PT对称介质中，艾里-高斯光束可以形成振荡孤子，且可稳定传输。孤子的峰值强度随P、W0、a的增大而增大，随 ω的增大而减小；振荡周期随P和 ω的增大而减小，随W0的增大而增大。当 χ0增大时，在0< χ0<0.55范围内，孤子的峰值强度变化不明显；当 χ0>0.55时，孤子的峰值强度迅速减小。该研究结果可为孤子在复杂非均匀介质中的传输及全光控制方面的应用提供理论基础。 In this study, the propagation and control of Airy-Gaussian beams in Gaussian parity-time (PT) symmetric media are investigated numerically, by utilizing the nonlinear Schrödinger equation as a theoretical model. The impacts of the characteristic parameters of Gaussian PT symmetric media (modulation depth P, modulation factor ω, and gain/loss factor W0) and the characteristic parameters of Airy-Gaussian beams (truncation factor a, distribution factor χ0) on propagation characteristics of Airy-Gaussian beams are examined in detail. The results demonstrate that the Airy-Gaussian beams can produce oscillating solitons and transmit steadily in Gaussian PT symmetric media. The soliton strength increases with the increase of P, W0, and a, and decreases with the increase of ω. The oscillation period decreases with the increase of P and ω and increases with the increase of W0. When χ0 increases, when 0< χ0<0.55, the peak intensity of the soliton does not change obviously; when χ0>0.55, the peak intensity of the soliton decreases rapidly. This research can offer a theoretical foundation for the use of soliton transmission in complicated heterogeneous media and all-optical control.
摘要：
The propagation characteristics of Airy beams in an inhomogeneous medium with periodic potential are studied theoretically and numerically. The Gross-Pitaevskii equation was solved with periodic potential using the separating variables method, and a breathing soliton solution and the breathing period were obtained. Further, the propagation properties of an Airy beam, and the interaction between two Airy beams while considering the medium parameters and beam parameters were numerically simulated in detail. First, we discuss the influence of the initial medium parameters (modulation intensity P and modulation frequency ?) on the propagation characteristics. Then, we investigate the effect of the initial beam parameters (initial chirp C and position x(0)) on the propagation characteristics. Lastly, the interaction of two Airy beams with opposite spatial positions for different phase f, amplitude A, and initial interval x(0) is analyzed. The breathing period and central position of the breathing solitons could be controlled by changing the initial medium parameters. By varying the initial beam parameters, the deflection direction and size, and the maximal intensity of the breathing solitons were manipulated. The breathing solitons of different bound states were formed by changing the phase f, amplitude A, and initial interval x(0) of two Airy beams. The results provide a theoretical basis for the propagation and manipulation of Airy beams.
摘要：
The supercontinuum generation and manipulation of Airy-Gaussian pulses in a photonic crystal fiber with three zero-dispersion points are studied using the split-step Fourier method. Firstly, the spectral evolution of Airy-Gaussian pulses in four photonic crystal fibers with different barrier widths was discussed, and the optimal fiber was determined after considering the factors of width and flatness. By analyzing the mechanism of supercontinuum generation in photonic crystal fibers with single, double and three zero-dispersion points, it is found that the photonic crystal fiber with three zero-dispersion points have a larger spectral width due to the component of tunneling solitons. Then, the effects of four characteristic parameters (truncation factor a, distribution factor chi 0, initial chirp C and central wavelength lambda) on forming the supercontinuum spectrum of Airy-Gaussian pulses are analyzed in detail. The results show that the spectral width and energy intensity of the dispersive wave and tunneling soliton generation can be well controlled by adjusting the barrier width and initial parameters of the pulse. These research results provide a theoretical basis for generating and manipulating high-power mid-infrared supercontinuum sources.
期刊：
Open Physics,2022年20(1):1031-1040 ISSN：2391-5471
通讯作者：
Yangbao Deng
作者机构：
[Xiong, Cuixiu; Leng, Xiaoling; Zhang, Guangfu; Zhang, Saiwen; Chen, Liezun; Wen, Bing; Deng, Yangbao] Hunan City Univ, Coll Informat & Elect Engn, All Solid State Energy Storage Mat & Devices Key, Yiyang 413000, Peoples R China.;[Wen, Bing] Hunan Univ, Sch Phys & Elect, Key Lab Micro Nanooptoelect Devices, Minist Educ, Changsha 410082, Hunan, Peoples R China.
通讯机构：
[Yangbao Deng] A;All-Solid-State Energy Storage Materials and Devices Key Laboratory of Hunan Province, College of Information and Electronic Engineering, Hunan City University, Yiyang 413000, China
摘要：
We numerically investigate and statistically analyze the impact of medium parameters (modulation depth P, modulation factor ω, and gain/loss strength W 0) and beam parameters (truncation coefficient a and distribution factor χ 0) on the propagation characteristics of a cosh-Airy beam in the Gaussian parity-time (PT)-symmetric potential. It is demonstrated that the main lobe of a cosh-Airy beam is captured as a soliton, which varies periodically during propagation. The residual beam self-accelerates along a parabolic trajectory due to the self-healing property. With increment in P, the period of a trapped soliton decreases almost monotonically, while the peak power of a trapped soliton increases monotonically. With the increase in ω or decrease in the absolute value of W 0, the period and peak power of a trapped soliton decrease rapidly and then almost remain unchanged. Moreover, it is indicated that the period of a trapped soliton remains basically unchanged no matter a and χ 0 increase or decrease. The peak power of a trapped soliton increases with increment of a, but the peak power of a trapped soliton stays relatively constant irrespective of variation in χ 0.
作者机构：
[Chen, Depeng; Leng, Xiaoling; Wen, Bing; Deng, Yangbao] Hunan City Univ, Coll Informat & Elect Engn, All Solid State Energy Storage Mat & Devices Key, Yiyang 413000, Peoples R China.;[Wen, Bing; Wei, Jiamou] Hunan Univ, Sch Phys & Elect, Key Lab Micro Nanooptoelect Devices, Minist Educ, Changsha 410082, Peoples R China.
通讯机构：
[Yangbao Deng; Bing Wen] A;Authors to whom correspondence should be addressed.<&wdkj&>All-Solid-State Energy Storage Materials and Devices Key Laboratory of Hunan Province, College of Information and Electronic Engineering, Hunan City University, Yiyang 413000, China<&wdkj&>Authors to whom correspondence should be addressed.<&wdkj&>All-Solid-State Energy Storage Materials and Devices Key Laboratory of Hunan Province, College of Information and Electronic Engineering, Hunan City University, Yiyang 413000, China<&wdkj&>Key Laboratory for Micro-/Nano-Optoelectronic Devices of Ministry of Education, School of Physics and Electronics, Hunan University, Changsha 410082, China
摘要：
The evolution of Cos−Gaussian beams in periodic potential optical lattices is theoretically and numerically investigated. By theoretical analysis, a breathing soliton solution of the Gross–Pitaevskii equation with periodic potential is obtained, and the period of the breathing soliton is solved. In addition, the evolution of Cos−Gaussian beams in periodic potential optical lattices is numerically simulated. It is found that breathing solitons generate by appropriately choosing initial medium and beam parameters. Firstly, the effects of the initial parameters of Cos−Gaussian beams (initial phase and width) on its initial waveform and the propagation characteristics of breathing soliton are discussed in detail. Then, the influence of the initial parameters (modulation intensity and modulation frequency) of a photonic lattice on the propagation characteristics of breathing solitons is investigated. Finally, the effects of modulation intensity and modulation frequency on the width and period of the breathing soliton are analyzed. The results show that the number of breathing solitons is manipulated by controlling the initial parameters of Cos−Gaussian beams. The period and width of a breathing soliton are controlled by manipulating the initial parameters of a periodic photonic lattice. The results provide some theoretical basis for the generation and manipulation of breathing solitons.
作者机构：
[文兵; 邓杨保; 张赛文; 陈德鹏; 邓曙光; 张光富] All-solid-state Energy Storage Materials and Devices Key Laboratory of Hunan Province, College of Information and Electronic Engineering, Hunan City University, Yiyang;413000, China;[韦家谋] Key Laboratory for Micro-/Nano-Optoelectronic Devices of Ministry of Education, School of Physics and Electronics, Hunan University, Changsha;410082, China;[文兵] 413000, China<&wdkj&>Key Laboratory for Micro-/Nano-Optoelectronic Devices of Ministry of Education, School of Physics and Electronics, Hunan University, Changsha
通讯机构：
[Deng, Y.] A;All-solid-state Energy Storage Materials and Devices Key Laboratory of Hunan Province, China
关键词：
cosh-Airy脉冲;双零色散介质;超连续谱;操控
摘要：
结合分步傅里叶方法和四阶Runge-Kutta积分法，研究了有限能量cosh-Airy脉冲在双零色散介质中的超连续谱产生与操控。首先，详细讨论了特征参数截断系数a、初始啁啾C和分布因子χ0对cosh-Airy脉冲在双零色散介质中的演化影响，并统计了a、C和χ0对超连续谱宽度的影响。然后，进一步研究了高阶非线性效应对cosh-Airy脉冲产生超连续谱的影响。结果表明：通过操控cosh-Airy脉冲的特征参数可以控制超连续谱的宽度；当存在高阶非线性效应时，超连续谱的平坦性会受到影响。研究结果为超连续谱的产生和操控以及宽带激光光源提供一些理论基础。 Combining the split-step Fourier method with the fourth-order Runge-Kutta integration method, the manipulation and generation of supercontinuum by finite energy cosh-Airy pulses in a double-zero dispersion media was investigated. Firstly, the influences of truncation coefficient a, initial chirp C and distribution factor χ0 on the evolution of cosh-Airy pulses in double-zero dispersion medium were discussed in detail, and the influences of a, C and χ0 on the width of supercontinuum width were statistically analyzed. Then, the influences of higher-order nonlinear effects on supercontinuum generation of cosh-Airy pulse was further studied. The results show that the width of supercontinuum can be controlled by manipulating the characteristic parameters of cosh-Airy pulses. The flatness of supercontinuum is affected with consideration of high-order nonlinear effects. The results provide some theoretical basis for manipulation and generation of supercontinuum and broadband laser sources.
作者机构：
[张赛文; 邓亚琦; 王冲; 冷潇泠; 张光富; 文兵; 邓杨保; 谭伟石; 田野; 李稳国] School of Information and Electronics Engineering, Hunan City University, Yiyang;413000, China;All-solid-state Energy Storage Materials and Devices Key Laboratory of Hunan Province, Hunan City University, Yiyang;[张赛文; 邓亚琦; 王冲; 冷潇泠; 张光富; 文兵; 邓杨保; 谭伟石; 田野; 李稳国] 413000, China<&wdkj&>All-solid-state Energy Storage Materials and Devices Key Laboratory of Hunan Province, Hunan City University, Yiyang;[张赛文; 邓亚琦; 王冲; 冷潇泠; 张光富; 文兵; 邓杨保; 谭伟石; 田野; 李稳国] 413000, China
通讯机构：
[Deng, Y.] S;[Deng, Y.] A;All-solid-state Energy Storage Materials and Devices Key Laboratory of Hunan Province, China;School of Information and Electronics Engineering, China
摘要：
Copper nanowires (CuNWs) are a key building block to facilitate carrier conduction across a broad range of nanodevices. For integration into nanoscale devices, manipulation and welding of these nanowires need to be overcome. Based on high energy density laser processing investigation, we report on innovative welding of single CuNWs to a silver film using a tightly focused laser beam combined with manipulation of CuNWs through the dielectrophoresis (DEP) method. Two types of lasers, femtosecond (FS) and continuous-wave (CW), were employed to analyze, improve, and control Cu-NW melting characteristics under high energy density irradiation. The FS laser welding of CuNWs resulted in a metallic joint with a low contact resistance suitable for functional electronic nanodevices. Computational simulations using the 1-D heat diffusion equation and finite difference method (FDM) were performed to gain an insight into metal-laser interactions for high performance welded contact development. Simulation studies on lasers established contrasting melting behavior of metal under laser irradiation. The device feasibility of CuNW based welded contacts was evaluated in terms of the electrical performance of a glucose sensor. It was possible to sense glucose concentration down to 10(-6) M, demonstrating a path towards integration of CuNWs into wearable, flexible nanoelectronic devices.
