亚波长光栅反射特性研究  

Research on Reflection Characteristics of Sub-Wavelength Gratings

作　　者：郭楚才[1] 叶卫民[1] 袁晓东[1] 张检发[1] 曾淳[1] 季家镕[1] 

机构地区：[1]国防科技大学光电科学与工程学院,湖南长沙410073

出　　处：《光学学报》2009年第12期3272-3276,共5页Acta Optica Sinica

摘　　要：亚波长光栅具有特殊的反射特性,可以用于各种光器件的设计。利用时域有限差分方法(FDTD)和散射矩阵方法计算了亚波长介质光栅的能带结构、本征模式以及反射谱。模拟结果显示:光栅反射谱中的共振峰是由光栅的泄漏模式引起的;在正入射和斜入射条件下,外部入射场所能激励的光栅的模式不同;通过控制光栅本征泄漏模的频率和Q值可以控制反射谱线型。实验利用电子束直写以及反应离子刻蚀等方法在绝缘体上硅(SOI)晶圆上制备出亚波长光栅结构,实验测量所得光栅的反射谱线型与模拟结果吻合得很好。Sub-wavelength gratings can be applied in the design of various optical devices for the special reflection characteristics. The band structure, eigenmodes and reflection spectra of sub-wavelength dielectric gratings are simulated with finite-difference time-domain （FDTD） method and scattering-matrix method. Simulation results show that the resonant peaks of the reflection spectra originate from the leaky modes and eigen modes excited by external incident waves are different between normal and oblique incident conditions. Further more, the reflection spectra line shape of the grating can be controlled by controlling the frequencies and Q factors of the leaky modes. In the experiments, sub-wavelength gratings in silicon-on-insulator （SOI） substrate are fabricated by electron beam lithography and reactive ion etching methods. Experimental reflection spectra of the fabricated grating agrees well with the simulation results.

关 键 词：光栅 反射特性 时域有限差分 亚波长光栅 电子束直写 反应离子刻蚀 

分 类 号：O436[机械工程—光学工程]