Journal article
Eye-safe diode laser Doppler lidar with a MEMS beam-scanner
Department of Photonics Engineering, Technical University of Denmark1
Optical Sensor Technology, Department of Photonics Engineering, Technical University of Denmark2
Department of Physics, Technical University of Denmark3
Risø National Laboratory for Sustainable Energy, Technical University of Denmark4
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.
Language: | English |
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Year: | 2016 |
Pages: | 1934-1942 |
ISSN: | 10944087 |
Types: | Journal article |
DOI: | 10.1364/oe.24.001934 |
ORCIDs: | Pedersen, Christian and Rodrigo, Peter John |