Low-Insertion-Loss Optical Matrix Switch Using MEMS Micromirrors Assembled by Passive Alignment(<Special Issue>Micro Mechanical Engineering)

A three-dimensional (3D)-type MEMS optical switch with low insertion loss and low assembly cost has been developed. The switch consists of two optical beam scanners placed facing each other. Each scanner consists of a collimator array and two mirror arrays. The scanner controls the direction of each optical beam by means of two single-axis mirrors. The mirror arrays are fabricated by MEMS technology and contain holes through which the beam traverses in each mirror array. The mirror arrays are stacked directly on the collimator array, which is passively aligned using pins and alignment holes. Based on this structure, a prototype 32-port (with three extra ports) optical switch was developed. Measured insertion loss of six arbitrary paths in the switch is in the range of 1.5-1.9dB. It is thus concluded that a 3D-type optical switch assembled by wholly passive alignment with lower insertion loss than 2dB is feasible.