光开关——晶格常数对光子晶体透射特性调制功能

Photoswitch——Modulation Function of Lattice Constant on the Transmission Characteristics of Photonic Crystal

为设计高性能、高灵敏度的新型光学开关,利用传输矩阵法理论,通过数值计算和绘图仿真的方式,研究介质晶格常数对光子晶体分立透射谱的影响规律,结果表明光子晶体的透射特性对介质晶格常数变化的响应非常灵敏:随着A层介质晶格常数增大,光子晶体分立透射峰向低频方向移动,而且高频一侧的分立透射峰出现简并成透射带现象;随着B层或D层介质晶格常数增大,光子晶体分立透射峰向低频方向移动,但分立透射峰条数不变且不出现简并成透射带现象;随着C层介质晶格常数增大,光子晶体分立透射峰也向低频方向移动,但出现简并成透射带现象却发生在低频一侧的分立透射峰;当各介质层的晶格常数同时增大时,光子晶体分立透射峰迅速向低频方向移动,但分立透射峰的条数不变且不出现简并成透射带现象。光子晶体传输特性对晶格常数变化的响应规律,为光子晶体实现高灵敏度的光学开关功能提供理论依据。

In order to design a new type of photoswitch with high performance and sensitivity, the influence of lattice constant of dielectric on the discrete transmission spectrum of photonic crystal is studied by the theoretical transmission matrix and numerical simulation method. The result shows that the transmission properties of photonic crystals are very sensitive to the response of the lattice constant of the medium. The discrete transmission peak of the photonic crystal is shifted to the lower frequency with the increase of the lattice constant of the A layer, and on the side of high frequency, the transmission peak appears simple and becomes a transmission band. With the in- crease of the lattice constant of the B or D layer, the discrete transmission peak is shifted to the lower frequency, but the peaks are not degenerated into a transmission band and the numbers of them are unchanged. The discrete transmission peak is also moving in the direction of low frequency with the increase of the lattice constant of the C layer, and the transmission peak appears simple and becomes a transmission band only in lower frequency. When the lattice constant of each layer is increased, the discrete transmission peak is moving rapidly to the lower frequency, but the number of discrete transmission peaks is not changed. The response of the photonic crystal to the lattice constant is the theoretical basis for the realization of the high sensitivity of the optical switch function.