非线性光纤布拉格光栅的飞秒激光制备及其低阈值全光开关的研究

项目名称： 非线性光纤布拉格光栅的飞秒激光制备及其低阈值全光开关的研究

项目编号： No.61308006

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 无线电电子学、电信技术

项目作者： 李存霞

作者单位： 西安理工大学

项目金额： 28万元

中文摘要： 全光开关是全光网络中的关键器件。本项目针对光纤布拉格光栅(FBG)光开关开启阈值功率高的问题，提出在具有高光学非线性的碲酸盐等玻璃光纤中制备相移FBG结构，同时利用材料的高非线性和相移光栅的场增强效应降低开关阈值；针对在此类高非线性光纤内制作FBG所面临的加工困难的问题，提出利用飞秒激光相位掩模微纳加工技术制备相移FBG结构。主要内容包括：研究非线性相移FBG的场增强效应和超短光脉冲在相移FBG中的传输规律，掌握场增强效应及非线性效应对开关特性的影响；探索利用飞秒激光在碲酸盐等高非线性玻璃光纤内制作相移FBG的关键技术，通过优化相移FBG的周期结构和相移等参数增强器件的场增强效应，降低开关阈值，提高其消光比；通过优化飞秒激光脉冲啁啾等微纳加工参数调控激光与光纤相互作用的非线性效应影响，实现激光诱导微结构的精确控制，研制阈值功率低于500mW、消光比大于6.5dB的低阈值FBG全光开关器件。

中文关键词： 光纤布拉格光栅；飞秒激光；光开关；；

英文摘要： The all-optical switch is a key component in the all-optical network. As a candidate of all-optical switch, fiber Bragg grating attracts more attentions. However, all-optical switch based on FBG meets the problem of high opening threshold power, which limits its application. To reduce opening threshold power of fiber Bragg grating optical switch, we propose the phase-shifted Bragg grating fabricated in high nonlinear glass optical fibers such as tellurate glass fibers, which is based on the high optical nonlinearity of materials as well as field enhancement effect in the phase-shifted Bragg grating. In view of the difficulty of fabricating FBG in high nonlinear glass fibers, the femtosecond laser micro-nano machining technique with phase mask is proposed to fabricate the phase-shifted FBG structure in the fibers. The main research content includes: (1) investigating field enhancement effect of nonlinear phase-shifted FBG and the propagation properties of ultrashort pulses in phase-shifted FBG. (2) clarifying the influence of field enhancement effect and nonlinear effect of phase-shifted FBG to its switch characteristics. (3) exploring the key technique of fabricating nonlinear phase-shifted FBG using femtosecond laser in high nonlinear glass optical fibers such as tellurate glass fibers. (4) reducing the open

英文关键词： Fiber Bragg grating；femtosecond laser；optical switch；；