兼具反射和透射模式的共振波导光栅滤波器的设计

Design of resonant waveguide grating filter with reflection and transmission modes

目前,应用于生物传感系统的共振波导光栅窄带滤波器仅能实现反射或透射的单一滤波模式。为了扩展被检样品的种类和提高样品的检测准确度,本文基于导模共振效应设计了兼具反射和透射模式的共振波导光栅滤波器。首先,基于经典的一维共振波导光栅结构,通过调节入射条件,设计了在同一波长(632.8 nm)处反射-透射模式可转换的滤波器,该滤波器在两种模式下均具有优良的滤波性能,光谱效率高于98%,Q因子大于1000。然后,从物理机制层面出发,分析了同一器件实现两种滤波模式的共振机理。结果表明:不同入射条件下,同一共振波导光栅结构在设计波长处可实现反射-透射窄带滤波模式的转换。

At present,narrow-band filter based on resonant waveguide grating structure applied to biosensors can only achieve a single filter mode of reflection or transmission.In order to expand the variety of samples and improve the accuracy of the samples testing,a resonant waveguide grating filter with both reflection and transmission modes was designed based on the guided mode resonance effect.Firstly,based on the classical one-dimensional resonant waveguide grating structure,a filter with convertible reflection-transmission mode at the same wavelength(632.8 nm)was designed by adjusting the incident conditions.In both modes,excellent filtering performance was presented,spectral efficiency was higher than 98%,and Q factor was greater than 1000.Then,the resonance mechanism for that the same device can realize two filtering modes was analyzed.The results showed that the reflection and transmission narrow-band filtering modes could be converted at the designed wavelength with the same resonant waveguide grating structure under different incident conditions.