2D MEMS vector scanning mirrors for LIDAR, medical imaging, and high laser power applications

Miniaturized vectorial beam steering mirrors are required in numerous applications like (i) LIDAR, (ii) diagnostic imaging or (iii) miniaturized therapeutic laser systems. To increase simultaneously static tilt angle (≥ ±5°) and mirror aperture (≥ 3mm) electro-dynamic driven MEMS vector scanners, actuated by moving magnet drives, were developed. Here, Fraunhofer IPMS uses a hybrid MEMS concept combining its experience in the fabrication of monolithic silicon 2D MEMS scanning mirrors with existing know-how in MEMS micro-assembly technologies. Two designs of electro-magnetic driven vectorial 2D MEMS scanners are presented, (i) a non-gimbaled 2D vector scanner with 8 mm mirror aperture and ≥ ±2° quasi-static tilt angle and (ii) a 2D vector scanner with gimble suspended moving magnet drive. The gimbaled electro-magnetic MEMS scanner has a 5 mm large aperture and enables large quasi-static tilt angles of ±13° on both scan axis. Eigenfrequencies are 142 Hz (X) and 124 Hz (Y) allowing non-resonant vectorial scanning with speeds up to 100…400°/s. A step response time < 10 ms is achieved in closed loop control for both axes. This hybrid electro-magnetic MEMS approach significantly expands the parameter space of the previous monolithic electro-static scanners.