通过研究波导两侧缺陷处的折射率对二维光子晶体波导透射光谱的影响，提出一种提高折射率传感器灵敏度的方案。计算结果表明光子透射带上边沿的偏移量与传感区折射率的大小存在一定关系，在相同的折射率变化量下通过改变波导两侧缺陷处圆孔的相关几何参数可极大提高光子透射带上边沿的偏移量，即提高折射率传感器的灵敏度。通过优化设计，传感器的灵敏度由折射率变化区间0.0~1.0 的55 nm/RIU(RIU 表示折射率单元)与1.1~2.0 的36 nm/RIU 分别提高到对应的405 nm/RIU 以及222 nm/RIU。

The transmission spectrum of a two- dimensional photonic crystal waveguide with edge defects of different refractive indexes (RIs) is analyzed, and accordingly a proposal to improve the sensitivity of RI sensor is put forward. The simulations and calculations show that the offset of the upper band edge of the transmission band is related to the RI of the analyte. For the same RI variation, the shift of the upper band edge of the transmission band can be greatly improved by changing the related geometrical parameters of holes at the defect area near both sides of the waveguide. Namely,the sensitivity of the RI sensor is enhanced. In this paper the sensitivity is respectively improved from 55 nm/RIU (RIU means refractive index unit) to 405 nm/RIU and 36 nm/ RIU to 222 nm/RIU corresponding to the range of the variation of RI (Dn) from 0.0 to 1.0 and 1.1 to 2.0 after the optimizing process.