Variable bandwidth optical filters with vertical micromirrors and silicon optical bench alignment technology

Abstract

A variable bandwidth, flat-passband optical filter based on a variable-aperture MEMS reflector was demonstrated. The filter is compatible with silicon-optical-bench technology. The reflecting mirror surface was defined by KOH wet-etching that produced a surface roughness of < 20 nm over the mirror. The optical bandwidth of the optical filter is continuously tunable from 3.4 nm to 6.3 nm.