Fraunhofer ISIT has more than 20 years of experience in the development of optical microsystems.
Optical microsystems are a key focal point in this business unit. Here ISIT develops MEMS scanners, that is to say scanning micromirrors including control and read electronics for different kinds of laser projection displays, for optical measuring and detection systems (such as LIDAR), and power applications in the fi elds of laser material processing and generative manufacturing. Based on a patented fabrication process, ISIT is currently the world’s only manufacturer of wafer-level vacuum packaged dual-axis MEMS scanners. Operating these scanning micromirrors in a vacuum environment offers signifi cant advantages.
Damping by the gas molecules is reduced to a minimum, enabling high-frequency scanning with unrivaled scan angles even at low electrostatic driving voltages. Hermetic encapsulation at the wafer level also results in the cost-effective and permanent protection of the scanning micromirrors against all kinds of contamination. This for example makes the steam sterilization of these MEMS scanners in an autoclave for endoscopy applications possible without causing damage.
ISIT has also realized a 3D camera with a depth resolution of just a few millimeters and a detectable object distance of 2 meters on the basis of 2D MEMS scanners. Novel scanning micromirrors with apertures of up to 2 centimeters and highly reflective coatings even permit highly dynamic dual-axis laser beam defl ection for CW laser outputs of up to 500 watts. In addition to capacitively driven scanning micromirrors, piezoelectrically driven scanning micromirrors are currently a research focal point at ISIT. This drive concept is particularly attractive due to its high force with simultaneous low energy consumption. Defl ections of up to 1600 μm have already been realized on individual scanning micromirrors of this type for resonant, translatory lifting movements.