3D imaging using resonant large-aperture MEMS mirror arrays and laser distance measurement

Abstract

We present a system concept for a scanning laser radar employing a newly developed MEMS mirror array. The array solution permits large reception apertures while preserving outstanding reliability, high scanning speed, compact size and small system weight. We show first results using a single-mirror prototype

Hybrid assembled micro scanner array with large aperture and their system integration for a 3D ToF laser camera

“…• use of a conventional electro mechanical drive for horizontal scanning: o enabling linear or adaptive scanning with 360° rotation or 120° oscillation In contrast to the monolithic 1D-MSM array LAMDA [1], the novel 1D-MEMS scanner array for Fovea is realized by hybrid assembly of frequency selected single scanner elements (see figure 4a). The Fovea MSM array consists of 22 receiver scanner elements (optimized for a large single aperture of 4.2 x 8.4mm²) hybrid assembled around the coaxial sending mirror -optimized for reduced dynamic mirror deformation and low beam divergence of 1mrad at λ = 1500nm.…”

“…Contrary, the aperture of a single MEMS scanning mirror is limited to small values of typically 1…3mm diameter due to the dynamic mirror deformation. To overcome the mentioned problems, Fraunhofer developed in [1] the concept for a MEMS-based LIDAR based on an array of identical synchronized driven MEMS elements. A first prototype LAMDA -developed for a phase shifting distance measuring system [2] -was limited to resonant 1D scanning at 250Hz and 60° FOV of a monolithic MEMS array with 80% optical filling factor, total aperture of 334.2 mm² consisting of 2x7 MEMS mirrors driven synchronized to a separate sending mirror (see figure 1a).…”

Quasi-static microscanner with linearized scanning for an adaptive 3D laser camera

“…Only 1.3 Hz frequency bandwidth were measured at MSA = ± 15.2°. Nevertheless, to enable a synchronized operation of multiple MEMS elements with reasonable yield and coast a hybrid assembly were chosen to build up the MEMS scanner array instead of a monolithic MEMS array originally used in [1] [3]. The deviation of resonance frequency was measured for several wafers.…”

“…Contrary, the aperture of a single MEMS scanning mirror is limited to small values of typically 1…3mm diameter due to the dynamic mirror deformation. To overcome the mentioned problems, Fraunhofer developed the concept for a MEMS-based LIDAR based on an array of identical synchronized driven MEMS elements [1]. A first prototype -developed for a phase shifting distance measuring system [2] -were limited to resonant 1D scanning at 250Hz and 60° FOV of a monolithic MEMS array with 80% optical filling factor, total aperture of 334.2 mm² consisting of 2x7 MEMS mirrors driven synchronized to a separate sending mirror [3].…”

Non-resonant 2-D piezoelectric MEMS optical scanner actuated by Nb doped PZT thin film

“…Micro electromechanical systems (MEMS) scanners have emerged as versatile optical components, and play important roles in wide applications such as displays [1][2][3][4], laser radars [5,6], barcode readers [7], tunable lasers [8] and optical biopsies [9,10]. Among these applications, biomedical imaging such as endoscopic optical coherence tomography (E-OCT) is one of the best matched applications for the MEMS scanner, because it can benefit from the small chip sizes, low-power consumption and high operation speed.…”