A bulk-micromachined silicon micromirror for tunable optical switch applications

A bulk-micromachined electrostatic micromirror has been presented for tunable optical switching devices. A silicon micromirror with (111) crystalline planes has been fabricated in the size of 1000 mu mX400 mu mX90 mu m. The optical switching function has been obtained by an electrostatic drive of the micromirror in the direction parallel to the substrate. In a static performance test, stable deflection of the micromirror has been observed up to the threshold deflection of 26.5 mu m with the threshold voltage of 330V. In a dynamic test, the resonant switching frequency has been measured as 590kHz. For the DC bias voltage range of 50-300V with an AC drive voltage of 10V, a continuous reduction of the resonant switching frequency has been demonstrated with the maximum frequency reduction of 23.7%.