Design and fabrication of an electromagnetically actuated optical switch with precise tilt angle control

An electromagnetically actuated MEMS mirror with precise tilt angle control for a bi-state optical switch is reported. A tilt angle control of ± 2.29° is achieved by utilizing the 4 μm BOX layer thickness of an SOI wafer together with carefully controlled backside deep silicon etching to construct precise mechanical stoppers. The device is die level packaged with a KOH etched textured silicon encapsulation to prevent scattering reflection from the back cavity to promote high contrast. Measurement results of tilt angle versus applied magnetic field correspond well with theoretical model prediction. The designed device is suitable for optical telecommunication in harsh environments that do not permit any electrical sparks.