构建以SiO2介质为基底，周期为1000 nm的高分子聚合物光子晶体，表面沉积高折射率介质覆层。建立了光子晶体生物传感器反射峰值波长与有效折射率间的关系。采用严格耦合波法(RCWA)理论分析了光子晶体传感器红外窄带反射谱特性，当光子晶体表面吸附介质的浓度变化时，有效折射率随之变化，导致反射峰值波长漂移。因此，可根据光子晶体生物传感器的反射峰值波长的漂移量获得表面吸附介质的分布特性。研究了生物传感器光子晶体表面覆层介质的折射率、厚度和填充比对反射特性和反射峰值波长漂移灵敏度的影响。结果表明，选择合适的覆层参数可提高光子晶体生物传感器的灵敏度。

A polymer photonic crystal biosensor with a period of 1000 nm is proposed on a SiO2 substrate. Then a high refractive index material is deposited on the surface of the photonic crystal. The rigorous coupled-wave theory is employed to analyze the characteristics of the narrow-band infrared reflection spectrum of the photonic crystal biosensor, and the relation between the peak reflection wavelength and the effective refractive index is established. With concentration of the analyte adsorbed on the surface of the photonic crystal varying, the effective refractive index changes simultaneously, which leads to a shift of the peak reflection wavelength. Therefore, the distribution of the analyte according to the amount of shift of the peak reflection wavelength is obtained. The influence of the coating with different refractive indices, thicknesses and filling ratios on the reflection spectrum and sensitivity of the shift of the peak reflection wavelength is also studied. The results indicate that the sensitivity of the biosensor can be improved by selecting appropriate parameters of the coating.