波状结构二维光子晶体负折射现象的研究

Analysis of the negative refraction in two-dimensional photonic crystals with wavy structure

结合波状结构二维(2D)光子晶体(PC)与入射介质两者的等频面结构分析了PC内部的负折射现象,采用时域有限差分(FDTD)方法模拟了高斯光束在波状结构2DPC内的负折射,分别得到了折射角/入射角以及折射角/入射波长之间的关系曲线,当入射角为45°,入射波段在1485—1530nm区域时,波状结构2DPC的负折射角与入射波长近似呈线性变化关系,并带有明显的PC超棱镜效应,采用端面投影方法对波状结构2DPC的入射端面和出射端面进行处理,改善了负折射时的透过率.

The negative refraction phenomenon in wavy two-dimensional （2D） photonic crystals （PC） is investigated with the isofrequency surfaces of PC and incident medium. The finite-difference time-domain method is used to simulate the negative refraction of incident Gaussian beam with different wavelengths and incident angles. When the incident angle is set at 45 degrees, the linear relation exists between the negative refraction angle and the wavelength within the range from 1485 to 1530nm, which is suitable for the superprism effect. In order to increase the transmission when negative refraction happened at large incident angles, interface projection method is employed.