线性损耗和双光子吸收下硅基波导调制不稳定性  

Modulation instability of silicon optical waveguide considering linear loss and biphotonic absorption

作　　者：周伟林[1,2] 罗风光[1] 余志华[1] 李斌[1] 赵新宇[1] 

机构地区：[1]华中科技大学光电子科学与工程学院,武汉430074 [2]湖南商学院计算机与电子工程学院,长沙410205

出　　处：《激光技术》2010年第4期489-492,共4页Laser Technology

基　　金：国家自然科学基金资助项目(60677023);国家八六三高技术研究发展计划资助项目(2006AA01Z240)

摘　　要：为了分析线性损耗和双光子吸收对硅基波导调制不稳定性的影响，采用理论论证和数值模拟相结合的研究方法，推导了调制不稳定性增益谱、峰值增益、峰值增益频率和调制带宽的表达式。论证了波导的线性损耗、双光子吸收系数和脉冲光功率等参量对调制不稳定性的影响，并对给定结构参量的脊波导进行了仿真分析。结果表明，即使在微弱的光功率（几十毫瓦）下，在反常色散区仍然存在强烈的调制不稳定性现象，其增益是相同功率下光纤介质的10^2～10^3倍；峰值增益频率和增益带宽随波导的线性损耗指数衰减；峰值增益也随双光子吸收系数指数减少。这为硅基波导调制不稳定性实验研究和超连续谱产生提供了理论参考。Taking into account the linear loss and biphotonic absorption effect of silicon-on-insulator （SOl） waveguide simultaneously, condition and gain spectra of modulation instability （MI） induced by combined effects of self-phase modulation and waveguide dispersions were investigated. Formulation for calculating the gain of MI was deduced theoretically, and expressions of peak gain, peak gain frequency and bandwidth of modulation instability were obtained as well. Impacts of various parameters on gain spectra of MI were analyzed theoretically and simulated in detail. Both theoretical analysis and simulation show that strong MI takes place even in the existence of low light power. The peak gain of MI is 2 to 3 orders of magnitude larger than that achieved in optical fibers with the same light power. Both peak gain frequency and bandwidth of gain spectra of MI are decreased exponentially with linear loss of waveguide, and peak gain is decreased exponentially with bi-photonic absorption of waveguide as well. The work provides an important reference for experimentally investigating modulation instability and supercontinuum generation in silicon waveguide.

关 键 词：光电子学 硅基波导 调制不稳定性 数值模拟 线性损耗 双光子吸收 

分 类 号：TN252[电子电信—物理电子学]