Free-space micromachined optical switches for optical networking

Fiber-optic switches with high port count have emerged as leading candidates for deployment in future optical transport networks, where restoration and provisioning in the optical layer will become increasingly important. This paper reviews the principle and performance of free-space micromachined optical switches (FS-MOS) featuring free-rotating hinged micromirrors. A single-chip FS-MOS that implements the critical function of bridging-essential for restoration in core optical networks is also proposed and demonstrated. The scalability of FS-MOS devices, and the dependence of their insertion losses on mirror-angle, are estimated theoretically. Simulation results suggest that the FS-MOS approach holds considerable promise for being expandable to the port-count values that will be needed in future core-transport lightwave networks