Free-space fiber-optic switches based on MEMS vertical torsion mirrors

This paper reports on the design, fabrication, and performance of a novel MEMS (micro-electro-mechanical-system) fiber-optic switch based on surface-micromachined vertical torsion mirrors. The vertical torsion mirror itself can be used as a 1/spl times/2 or an ON-OFF switch. A 2/spl times/2 MEMS fiber-optic switch with four vertical torsion mirrors has also been fabricated. The switching voltage is measured to be 80 V for switching angles of 45/spl deg/. We have achieved a switching time of less than 400 /spl mu/s (fall time) and an optical insertion loss of 1.25 dB for single-mode fibers. In addition, a bulk-micromachined silicon submount has been developed to package the switch with microball lenses and multimode fibers with passive alignment. With the micromachined switch chip and the hybrid-packaging scheme, the size, weight, and potentially the cost of the fiber-optic switches can be dramatically reduced.