Method and apparatus for curvature-resistant micro-mirror structures to reduce light beam loss in free-space micro-machined optical switches

摘要

A method and apparatus for curvature-resistant micro-mirror structures to reduce light beam coupling loss due to mirror curvature in free-space micro-machined optical switches is presented. As a significant contributor to light beam coupling loss is the curvature of the micro-mirrors in these cross-connect systems, an improved thick mirror slab utilizing a phosopho-silicate glass (PSG) core is constructed. The PSG core is sandwiched between two poly-silicon layers, thus providing an enhanced, bending-resistant structure which protects the PSG core from the release etchant used in surface micro-machining and substantially reduces mirror curvature. The reflective layer is laid down on top of the enhanced, bending-resistant structure.