A three-dimensional micro-electro-mechanical system (MEMS) optical switch module using low-cost highly accurate polymer components

This paper describes a large-scale, compact three-dimensional (3D) micro-electro-mechanical system (MEMS) optical switch using two-axis tilt mirror arrays and free-space optics. This switch structure provides a practical solution for constructing a large-scale switching fabric due to its high density and low cost features. The MEMS mirrors are made of single-crystal silicon with integrated gimbal structures and are tilted two dimensionally by electrostatic force. In the mirrors, the driving electrode has a three-dimensional terrace structure and they effectively reduce the control voltage compared with conventional MEMS mirrors. The free-space optics consists of low-cost high-precision polymer components and is passively assembled in a series of simple steps. A prototype module with 100-channel optical fiber input/output has an overall hardware volume of approximately 170 cc (80 × 60 × 35 mm), and this exhibited a low coupling loss of 4.0 dB and a switching time of 3 msec.