Vectorial microscanning mirror with integrated position sensor for fast beam steering of a compact therapeutic laser

Miniaturized beam steering mirrors are required in numerous applications like (i) LIDAR, or (ii) miniaturized therapeutic lasers. Recently, Fraunhofer IPMS developed a new type of electrostatic vectorial (2D quasi-static) MEMS scanning mirror. The vectorial MEMS scanner was specially optimized for the requirements of the new highly compact therapeutic medical laser system. This laser application requires a highly miniaturized MEMS scanning system for fast and precise vectorial beam positioning of the treatment laser with a positioning time of ≤ 5 ms. The quasi-static 2D drive of the vectorial MEMS scanner is based on vertical comb actuators in combination with a non-cardanic suspension of the 2.2 mm circular mirror, For high laser powers of > 1.5 W (CW) at 519 nm, highly reflective coatings based on enhanced (hybrid) Al with R ≥ 98 % are used. In this contribution we focus on the experimental investigation and optimization of the positioning dynamics of the vectorial MEMS scanning mirrors to achieve a fast and precise beam steering of the medical treatment laser. Furthermore, we discuss the packaging and system integration of the MEMS scanning mirrors in more detail.