Wavelength-selective integrated optical MEMS filter in InP

This paper presents a low-power, electrostatically-actuated integrated optical filter on an InP MEMS platform. The micromachined filter achieves a resonant wavelength shift of 12nm (1513-1525nm) at a low operating voltage (7V). The filter consists of a half-wavelength long resonant cavity bound by two highly reflective distributed Bragg reflector (DBR) mirrors fabricated by lithography and dry-etching. The filter is integrated monolithically with a doubly-clamped suspended-beam capacitive microactuator and optical waveguides. This paper discusses the fabrication as well as experimental results, showing good agreement between the measured and simulated performance of the filter. The novelty of the device lies in its in-plane MEMS actuation scheme enabling easy integration with other waveguide-based planar integrated optical active and passive components on an InP optoelectronic chip.