多系双局域态光子晶体的可调谐滤波特性分析

利用紧束缚方法分析了双局域态光子晶体产生双缺陷模的机理, 采用传输矩阵法研究了一维光子晶体的光学传输特性, 并得到了透射谱与晶体结构参数的关系, 在此基础上讨论了光子晶体在受到单轴应力时所表现出的介观压光效应, 据此设计了一种结构简单的应力调制的近红外波段的多通道滤波结构.通过数值模拟可以看出, 随着各介质层折射率或厚度的增加, 缺陷模发生红移.当对多系双局域态光子晶体施加单轴拉伸应力时, 各缺陷峰都向长波长移动, 且缺陷峰峰值基本不变.经过数值拟合, 缺陷峰中心波长与对光子晶体施加单轴拉伸应力所产生的应变呈线性关系.该滤波器结构简单、可调谐性好, 在一系列精巧的光子晶体激光器、波分复用器或者其他精密仪器的制造中有一定的应用价值.

Tunable filtering prop erties of the p olyphyly photonic crystal with double lo cal states

The mechanism of generating double defect modes in a photonic crystal with double local states is analyzed based on the tight-binding method. The optical transmission characteristic of a one-dimensional photonic crystal is studied using the transfer matrix method. And the relationship between the transmission spectrum and structural parameters of the photonic crystal is obtained. The mesoscopic calender effect is discussed when the photonic crystal is exerted on by a homotaxial stress on the basis of these theories. Therefore, a multichannel filter with a simple structure which can be modulated by the stress in the near infrared band is designed. Numerical simulation results show that the defect modes may produce a red shift with the increase of the dielectric layers' refractive index or thickness. When the uniaxial tensile stress is applied on the ployphyly photonic crystal with double local states, all defect peaks will move to the direction of the long wavelength, and the values of these defect peaks remain unchanged basically. Through numerical fitting, the relationship between these defect peaks' central wavelengths and the size of the strain produced by the homotaxial tensile stress on the photonic crystal is linear. This kind of photonic crystal filter with a simple structure has good tunability and has practical application value in the manufacture of a series of exquisite photonic crystal lasers, wavelength division multiplexers and other precision instruments.