硫系光波导色散调控及非线性应用的研究

发布时间：2018-03-15 07:18

本文选题：硫系玻璃　切入点：光波导　出处：《宁波大学》2017年硕士论文　论文类型：学位论文

【摘要】：近年来,有着一系列独特光学特性的硫系玻璃,如由于较高的折射率而具有的良好的光场限制作用,较高的非线性折射率,较宽的红外透过窗口(可以达到20mm)和在通信波段可以忽略的双光子吸收以及自由载流子吸收,逐渐成为了制作平面光学波导的理想材料,在现代集成中红外光学器件研发领域具有极大的发展前景。现在许多全光进程已经采用有色散工程的硫系光波导,其中包括参数放大,波长转换,频分复用,超连续谱的产生等。因此,硫系玻璃在诸多领域有着十分广阔的应用前景和研究意义。色散控制作为硫系光波导的本质属性,在非线性过程中起着重要作用,因为对于许多非线性应用,如超连续谱的产生,四波混频(FWM),波长转换,参量放大,孤子裂变等需要平坦的低的色散曲线。在宽波长范围内低的平坦色散可以用于优化相位匹配,这对许多非线性处理是有益的。然而,硫系材料在近红外和中红外通常有大的负的材料色散,需要特别的波导结构设计,用波导色散来补偿材料色散。我们可以通过灵活调控波导的相关参数的方法来获得超宽带平坦色散曲线。本文主要围绕硫系玻璃材料展开课题的研究,并以此为基质从理论和仿真两个方面深入分析硫系光波导的特性,文章的组成结构如下:第一章绪论简要概述了光波导及其在非线性方面的效应,并且分析了硫系光波导的应用,介绍了硫系玻璃材料在光学方面的独特的性能特征,然后结合硫系材料的特性说明了本文的研究内容和意义。第二章介绍了光波导基本理论,并利用经典麦克斯韦方程组,通过推导得到满足光波传输的波动方程。并进一步分析了光脉冲传输的传输方程,通过进一步的学习推算出了广义非线性薛定谔方程。最后还介绍了分析光波导时需要的边界条件。第三章主要介绍了基于硫系材料的两种类型的光波导,通过有限差分的方法研究了硫系光波导色散特性和有效面积,并分析了其非线性系数。在参数优化的基础上,获得平坦的低的色散曲线。最后分析了在简并四波混频过程中的相位匹配条件。第四章在第三章的基础上,我们设计了一种新颖的脊形硫系玻璃波导(As_2S_3)结构,这种波导结构可以同时用于基本准TE和准TM模式。对于TE和TM模,通过色散调制的方法获得了具有两个ZDW的超宽带和低的色散曲线。此外,我们计算了两种模式的有效面积和非线性系数,并研究了在这种波导结构下超短脉冲泵浦时输出超连续谱的输出特性。第五章是对本文研究工作内容的总结,并指出了研究工作的缺陷及尚未解决的问题。
[Abstract]:In recent years, sulfur glasses with a series of unique optical properties, such as good light field limiting action due to their high refractive index, high nonlinear refractive index, The wide infrared transmission window (up to 20mm) and the negligible two-photon absorption and free carrier absorption in the communication band have gradually become the ideal materials for the fabrication of planar optical waveguides. In the field of modern integrated infrared optical devices, there is a great development prospect. Nowadays, many optical processes have adopted sulfur optical waveguides with dispersive engineering, including parameter amplification, wavelength conversion, frequency division multiplexing, etc. Therefore, sulfur glass has a broad application prospect and research significance in many fields. As the essential property of sulfur optical waveguide, dispersion control plays an important role in the nonlinear process. For many nonlinear applications, such as the generation of supercontinuum spectrum, FWM, wavelength conversion, parametric amplification, soliton fission and so on, flat low dispersion curves are required. Low flat dispersion can be used to optimize phase matching in a wide wavelength range. This is useful for many nonlinear processing. However, sulfur materials usually have large negative material dispersion in near infrared and middle infrared, requiring special waveguide structure design. Using waveguide dispersion to compensate material dispersion. We can obtain UWB flat dispersion curve by adjusting the relevant parameters of waveguide flexibly. The characteristics of sulfur optical waveguide are analyzed theoretically and numerically. The structure of the paper is as follows: chapter one is a brief introduction to the optical waveguide and its nonlinear effect. The application of sulfur optical waveguide is analyzed, and the unique optical properties of sulfur glass are introduced. Then, the research content and significance of this paper are illustrated with the characteristics of sulfur system. In chapter 2, the basic theory of optical waveguide is introduced. By using the classical Maxwell equations, the wave equation satisfying the light wave propagation is derived, and the transmission equation of the optical pulse transmission is further analyzed. The generalized nonlinear Schrodinger equation is derived by further study. Finally, the boundary conditions required for the analysis of optical waveguides are introduced. In chapter 3, two types of optical waveguides based on sulfur materials are introduced. The dispersion characteristics and effective area of sulfur optical waveguide are studied by finite difference method, and its nonlinear coefficient is analyzed. A flat low dispersion curve is obtained. Finally, the phase matching conditions in the degenerate four-wave mixing process are analyzed. In Chapter 4th, on the basis of Chapter 3, we design a novel structure of as _ 2s _ 3s _ 3 for a ridge sulfur glass waveguide. This waveguide structure can be used in both quasi-te and quasi-TM modes. For te and TM modes, UWB with two ZDW and low dispersion curves are obtained by dispersion modulation. We have calculated the effective area and nonlinear coefficients of the two modes, and studied the output characteristics of the supercontinuum spectrum when pumped by ultrashort pulses in this waveguide structure. Chapter 5th is a summary of the work in this paper. The defects of the research work and the unsolved problems are pointed out.
【学位授予单位】：宁波大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN252

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