全圆锥入射下基于一维共振波导光栅的入射角调谐滤波器

Incident angle-tuned filter based on 1D resonant waveguide grating in full conical mounting

本文提出并展示了一种全圆锥入射下基于一维共振波导光栅的入射角调谐滤波器。通过优化光栅层厚度,使其能够在支持TE导模的同时抑制TM导模。本文设计的滤波器呈现出可调谐的单一反射峰,峰值反射率理论上可达100%。当入射角改变时,共振波长可以由642.5 nm调节至484.6 nm。该反射峰是由一级衍射波与TE导模(基模)之间的共振效应所产生的。同样地,通过按比例增加光栅层的厚度和周期可实现应用于更高动态范围的可调谐滤波器。

This paper proposes and demonstrates a tunable filter using full conical mounting.The designed 1D resonant waveguide grating presents a tunable single reflection peak.The peak reflectance can theoretically reach 100%.The resonant wavelength can be tuned from 642.5 nm to 484.6 nm by changing the incident angle.The resonance between the 1st-order diffracted wave and fundamental transverse electric(TE)guided mode generates the reflection peak.This feature was achieved by optimizing the grating thickness to support the TE guided mode and suppress the transverse magnetic(TM)guided mode.The same concept can be applied to tunable filters with high dynamic range by increasing the thickness and period of grating in equal proportion.