Large aperture MEMS scanner module for 3D distance measurement

In this article we present a new large aperture 1D-MEMS scanner module especially designed for laser radar systems. The scanner module has a resonance frequency of 250 Hz and optical scan range of 60°. It comprises of two separate scanning channels: (a) a single scanning mirror of the collimated transmitted beam oscillates parallel to (b) a scanning mirror array of the receiver optics. The receiver optics use a synchronized array of 2 x 7 identical mirror elements, each with 2.51x 9.51 mm² per single mirror element, resulting in a total aperture of 334 mm² and filling factor of 80 %. We discuss in detail the system integration of the MEMS components including packaging and synchronized operation of all scanner elements to guaranty a large aperture of the LIDAR receiver optics. In addition the paper includes a conceptual discussion of optical design and expected S/N ratio and measurement range of final LIDAR system. It will be shown that the presented new concept of MEMS based LIDAR system can realize also high accuracy of the distance measurement similar to state of the art TOF-LIDAR scanners enabling a new generation of miniaturized, robust and potentially cost efficient LIDAR systems due to the MEMS technology