A thermally tunable, silicon-based optical filter

A novel silicon MEMS-based concept for tunable optical filters used in wavelength-division multiplexing (WDM) systems is presented. Such a filter is essential for monitoring and reconfiguring optical networks. The device is based on a Fabry-Perot interferometer employing a silicon cavity and silicon-based dielectric Bragg mirrors and is fabricated as a free-standing membrane. Wavelength tuning is achieved through thermal modulation of the resonator's optical thickness. Measurement of optical filter performance and tunability as well as numerical simulation results of its steady-state and transient thermal behavior are presented. (C) 2003 Elsevier Science B.V. All rights reserved.