Vertical micromirrors integrated with electromagnetic microactuators for two-dimensional optical matrix switches

We report novel single crystalline silicon (SCS) micromirrors vertically attached to electromagnetic microactuators for the two-dimensional (2-D) free-space optical cross-connect switching application. The operation voltage is typically 0.7 V due to the large electromagnetic force generated by the coils on the microactuators. Vertical micromirrors with the surface area of 500×1200 μm are monolithically integrated with microactuators. The micromirrors are fabricated by low-cost tetra-methyl ammonium hydroxide anisotropic wet etching on the [110] SCS wafers. The surface roughness of the micromirror is less than 20 nm and the measured insertion loss caused by the micromirror is approximately 0.2 dB. The large surface area of the micromirror can accommodate a big optical beam for 2-D matrix configuration to minimize insertion loss. Chips consisting of 10 × 10 arrays are successfully fabricated and tested.