Latchable electromagnetic 2×2 MEMS optical switch

This paper presents the design, fabrication process and measurement results of a 2×2 MEMS optical switch. The switch comprises of an electromagnet and lensed fibers assembled with a micromachined movable vertical micromirror. At a wavelength of 1550 nm, the insertion loss of 0.2-0.8 dB and the polarization dependent loss (PDL) of 0.02-0.2 dB are measured. The switching time is 1 ms. Novel method of realizing latchable optical switch using electromagnetic actuator is also provided and verified. The optical switch utilizes straw-cutter-like rotational motion of the shutter mirror compared to the comb-driven linear actuation achieved by the electrostatic force. The latching mechanism is based on the latchability of the electro-permanent magnet instead of the conventional arch-shaped mechanical leaf springs.