All-silicon bistable micromechanical fiber switch based on advanced bulk micromachining

Bulk silicon micromachining is used to fabricate bistable optical fiber switches. The switches are based on a silicon device consisting of an actuator for fiber movement and a V-groove fiber clamp for bistable operation. The complete mechanical structures including thermal actuators are etched into standard ⟨100⟩ silicon wafers using anisotropic wet etching in KOH. While switching is caused by asymmetric thermal expansion of a U-shaped silicon cantilever, the fiber clamp is driven by the bimaterial effect. The efficient process technology allows a low cost batch fabrication of these devices. The switches exhibit an insertion loss <1 dB and a crosstalk of <-60 dB using standard single-mode fibers. A switching power below 1 W is required during switching