As telecom networks increase in complexity there is a need for systems capable of manage numerous optical signals. Many of the channel-manipulation functions can be done more effectively in the optical domain. MEMS devices are especially well suited for this functions since they can offer large number of degrees of freedom in a limited space, thus providing high levels of optical integration.
We have designed, fabricated and tested optical MEMS devices at the core of Optical Cross Connects, WDM spectrum equalizers and Optical Add-Drop multiplexors based on different fabrication technologies such as polySi surface micromachining, single crystal SOI and combination of both. We show specific examples of these devices, discussing design trade-offs, fabrication requirements and optical performance in each case.
We are developing membrane mirrors for use in adaptive optics, particularly in astronomy and vision science. We have micro-fabricated membrane mirrors from single crystal silicon using wet chemical etching and reactive ion etching. Membrane size, tension and operating voltage were selected to allow greater deformation of the mirror surface at low operating voltage than previous membrane mirror designs. Mirror devices consist of independently fabricated membrane and electrode array chips that are flip chip bonded together. We have fabricated electrode arrays with 256 and 1024 electrodes, and active diameters ranging from 6-10 mm (comparable to the size of the human pupil). Membrane-electrode hybrids are mounted to ceramic packages, wire bonded, and driven by off chip, D/A electronics. These devices are milestones in the development of an electret membrane mirror.