基于非线性光纤的慢光可调谐延迟技术研究

项目名称： 基于非线性光纤的慢光可调谐延迟技术研究

项目编号： No.60871082

项目类型： 面上项目

立项/批准年度： 2009

项目学科： 金属学与金属工艺

项目作者： 张茹

作者单位： 北京邮电大学

项目金额： 32万元

中文摘要： 光纤中基于受激布里渊散射（SBS）可调谐慢光延迟技术在信号处理、光存储、光缓存和光路由等领域有重要应用前景，是近十年来光学领域的研究热点。本项目提出了一种基于非线性光纤产生强的SBS效果的慢光可调谐延迟技术。项目对掺杂纳米InP微粒的新型光纤进行数值计算，仿真出在布里渊增益G约为15时得到一个约为738ps的慢光延迟。从泵浦波、斯托克斯波、声波三波耦合方程出发，在考虑光纤损耗的情况下得到斯托克斯波的复波数、相折射率和增益及群折射率的表达式，并用MATLAB仿真慢光产生的K-K关系。 为了得到优化的慢光效果我们探索出高精确度的光外差探测法来测量SBS特性参数：布里渊阈值、布里渊增益谱、布里渊频移等。分别搭建了窄带SBS和宽带SBS系统。在窄带SBS中，采用了手动匹配法来严格满足泵浦光和斯托克斯信号光之间的频率匹配关系，实验中对于输入脉宽为200ns的脉冲得到了8ns的慢光延迟。在宽带SBS实验中，首先我们用相位调制器对可调谐激光器的输出光进行相位调制，得到等幅多线谱光谱。增益谱展宽到600MHz，且当增益为15时，输入脉宽为500ns的脉冲被延迟了32ns，且延迟效率达到5ns/dB。

中文关键词： 受激布里渊散射;SBS慢光;时延;非线性

英文摘要： Stimulated Brillouin scattering tunable slow-light technique in an optical fiber with its important application prospect in signal processing, optical storage, optical buffer and optical route, is a hot topic in Optical research field in recent years. A tunable slow-light technique based on strong SBS effect in nonlinear optical fibers is proposed in this project. Make numerical calculation in an optical fiber doped with nano-material InP, and a considerable time delay of~738ps is obtained when gain is ~15.Based on three-wave coupled equation, taking fiber losses into consideration, we deduce Stokes wave complex wavenumber，phase index，gain and group index , numerically simulate K-K relations via MATLAB. To optimize slow-light effect, we search heterodyne detection method to measure SBS characteristic parameters: Brillouin threshold, Brillouin gain spectrum, and Brillouin frequency shift. Narrow-band SBS and broad-band SBS system are both designed.In the narrow-band SBS system, we match frequency condition between pump and input signal manually due to its narrow gain spectrum, and get a delay of 8ns for a pulse with the 200ns bandwidth.In the broad-band SBS system, we modulate pump light using a phase-modulator to broad gain spectrum to 600MHz, and finally we obtain a delay of 32ns for a pulse with the 500ns bandwidth when gain is 15dB, and delay efficiency is 5ns/dB for the system.

英文关键词： stimulated Brillouin scattering;SBS slow light; time delay;nonlinearity