Eye-safe diode laser Doppler lidar with a MEMS beam-scanner

Abstract

We present a novel Doppler lidar that employs a cw diode laser operating at 1.5 μm and a micro-electro-mechanical-system scanning mirror (MEMS-SM). In this work, two functionalities of the lidar system are demonstrated. Firstly, we describe the capability to effectively steer the lidar probe beam to multiple optical transceivers along separate lines-ofsight. The beam steering functionality is demonstrated using four lines-ofsight -each at an angle of 18° with respect to their symmetry axis. Secondly, we demonstrate the ability to spatially dither the beam focus to reduce the mean irradiance at the probing distance (R = 60 m) of each lineof-sight -relevant for meeting eye-safety requirements. The switching time of the MEMS-SM is measured to be in the order of a few milliseconds. Time-shared (0.25 s per line-of-sight) radial wind speed measurements at 50 Hz data rate are experimentally demonstrated. Spatial dithering of the beam focus is also implemented using a spiral scan trajectory resulting in a 16 dB reduction of beam focus mean irradiance.

Large-Aperture kHz Operating Frequency Ti-alloy Based Optical Micro Scanning Mirror for LiDAR Application

“…Micro-mirror based LiDAR have drawn the attention of many researchers for the realization of 3D distance measurement [ 1 , 2 , 3 , 4 , 5 , 6 , 7 ]. Traditional laser scanners for LiDAR consist of heavy, expensive and large rotational optical devices.…”

MEMS-based lidar for autonomous driving

“…MEMS-based scanning mirrors have recently received much interest for their use in automotive lidar applications as a light-weight, compact and low power consumption scanning solution. Several MEMSbased lidar sensors have already been developed in various application such as space applications [33,34], robotics [35,36] and wind velocimetry [37], showing the feasibility of the technology. For automotive applications, Hoffman et al developed a 360 • scanning 2D MEMS scanner lidar with 60 • of azimuth angle [38] [41].…”

Dispersive optical phased array circuit for high-resolution pixelated 2D far-field scanning controlled by a single wavelength variable

“…Scanning LiDAR solutions can be based on a variety of technologies, such as mechanical (or MEMS-based) steering, 10,11 electronic steering or through an optical phased array. 9,12,13 One approach, which is promising in terms of SWAP as well as cost, is a chip-based, solid-state optical phased array (OPA).…”