复合介质柱缺陷光子晶体波导透射谱的研究

为了更好地利用光子晶体的导光和滤波性质,采用时域有限差分方法研究了在光子晶体波导中引入复合层状介质柱缺陷后,复合层状介质层的材料在折射率、厚度等参量改变时,2维光子晶体透射率随入射光频率变化的关系。结果表明,随着介质柱半径及折射率的增大,透射谱中导带内出现更多模式的缺陷态,当介质柱半径接近光子晶体空气柱半径时,可以产生频率范围更大的导带,介质柱折射率比较大时,会在导带内形成窄的禁带。实际应用时可根据具体需要调节。该研究为利用光子晶体制作滤波器和光开关等器件提供了理论基础。

Research of the transmission spectra of photonic crystal waveguidewith layered composite medium cylinder

The transmission property of the two-dimension photonic waveguide after introducing layered composite medium cylinder defect was studied by means of the finite-difference time-domain method when changing the radius and refraction index of the cylinder.The results show that more defect states appear in guided gap with the radius and refractive index of the medium cylinder increasing.Even broader guided gap appears when radius of medium cylinder is close to that of air cylinder.Narrow forbidden gap appears in guided gap with big refraction index of the cylinder.The results are very meaningful for design of 2-D photonic crystal devices.