波导层介质对二维光子晶体反射光谱的影响

构建了基底介质为SiO2、表面覆层介质为TiO2 的二维光子晶体，采用严格耦合波法分析了二维光子晶体的窄带光学传输特性。分析了二维光子晶体的晶格周期、波导层的折射率及厚度对其反射光谱的影响。分析结果表明:当光子晶体的晶格周期和波导层介质厚度为常数时，随着波导层介质折射率的增大，光子晶体的反射峰值波长红移，且波导层折射率与反射峰值波长呈线性关系。当光子晶体波导层介质折射率为常数时，波导层厚度增大或光子晶体晶格周期的增大都会引起光子晶体反射峰值波长增大，但这两个参数与反射峰值波长只是在一定的变化范围内为线性关系。此种结构的二维光子晶体覆层表面吸附分布不均匀的介质时，通过分析光子晶体的呈现光谱可获得其表面吸附介质的不均匀特性。

Effects of waveguide layer on reflection spectrum characteristic of two-dimensional photonic crystal

The two-dimensional(2D) photonic crystal(PC) was constructed with the substrate of SiO2 and the surface coating medium of TiO2, and rigorous coupled-wave analysis (RCWA) theory was used to analyze the optical propagation property of 2D PC. The effects of the lattice period, refractive index and thickness of waveguide layer on optical properties of 2D photonic crystal were analyzed. Analysis results show that: While the lattice period and thickness of the waveguide layer are constant, with the increase of refractive index of waveguide layer, the reflective peak wavelength value (PWV) appears red shift, and there is a good linear relationship between above two. When the refractive index of waveguide layer is constant, photonic crystal reflection PWV increases with the increase of thickness or lattice period, the linear relationship between the two and PWV is in certain range. The non-uniform characteristic of surface adsorbing medium is obtained by analyzing the spectrum of non-uniform distribution of surface adsorbing medium of 2D PC.