A MEMS electromagnetic optical scanner for a commercial confocal laser scanning microscope

A MEMS electromagnetic optical scanner for horizontal scanning of a commercial confocal laser scanning microscope has been developed. The purpose is to replace the currently used commercially available scanner with our new MEMS scanner in an existing microscope product, and therefore, the scanner specifications have to be compatible with those of the current one. Electromagnetic actuation is selected because of the millimeter-sized mirror, and a single crystal silicon hinge is used for realizing high-speed scanning with sufficient scan angle. In order to maintain mirror flatness for high quality optics requirement, the whole wafer thickness (300 μm) is used as the mirror, resulting in a large moment of inertia, and this has been taken into consideration in the actuator design. Although few MEMS actuators have been commercialized to date, it has successfully satisfied all the specifications including not only the fundamentals such as resonant frequency and scan angle but also those for the commercial product such as scanning stability and reliability. It has been commercialized as a part of our product, Olympus OLS1100 (remodeled as OLS1200 in August 2002).