TRIPLE ELECTRODE MOEMS TUNABLE FILTER AND FABRICATION PROCESS THEREFOR

摘要

A MOEMS Fabry-Perot tunable filter 100 includes an optical membrane structure 150. Two electrostatic cavities 136, 138 are provided, one on either side of the membrane structure 150. As a result, electrostatic attractive forces can be exerted on the optical membrane to enable deflection in either direction, typically, along the optical axis 10. This is useful in calibrating the tunable filter during operation to a lambd° set point. It is also useful in controlling the membrane to avoid unstable operation and increasing a deflection range.