Abstract

Tunable optical filters are important for applications such as DWDM optical networks, spectroscopy, reconfigurable focal plane arrays, and sensing.^1-7 Micromechanically actuated filters are desirable because of their wide tuning range, design flexibility and high yield. The device structure consists of epitaxial layers forming a single Fabry-Perot cavity, having two Distributed Bragg Reflectors (DBRs) and an air gap in-between (formed by removal of a sacrificial layer). The top DBR moves towards the bottom DBR with an applied voltage resulting in a change in the transmitted wavelength. We recently reported >100 nrn tuning around 1550 nm using a torsional structure.⁵ The structures are readily adaptable to tunable VCSELs and detectors.^6-7 However, a simple set of design rules have never been discussed. In particular, it is of great interest to explore how we may adapt the design for wide wavelength regimes, e.g. 1-10 μm. The purpose of this paper is to determine how scalable the various designs are and to establish the design rules.

© 2002 Optical Society of America