A 45°-tilted 2-axis scanning micromirror integrated on a silicon optical bench for 3D endoscopic optical imaging

This paper presents a 2-axis electrothermal single-crystal-silicon (SCS) micromirror that is tilted 45° out of plane on a silicon optical bench (SiOB). The SiOB provides mechanical support and electrical wiring to the tilted 2-axis mirror as well as an aligned trench for assembling other optical components such as optical fibers. The tilt of the mirror is achieved with the bending of a set of stressed bimorph beams and the stop is provided by the silicon sidewall. The tilt angle can be precisely controlled by properly choosing the distance from the mirror frame to the silicon sidewall and the flexure bimorph length. The mirror plate is 0.72 mm × 0.72 mm and the footprint of the entire MEMS device is 2.22 mm × 1.25 mm. The measured maximum optical scan angles of the mirror are 40.0° in both x- and y-axis.