Design Of Resonant Waveguide Grating Filter With Reflection And Transmission Modes

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 1 000. 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.