Frequency-resolved coherent lidar using a femtosecond fiber laser

We demonstrate a coherent lidar that uses a broadband femtosecond fiber laser as a source and resolves the returning heterodyne signal into N spectral channels by using an arrayed-waveguide grating. The data are processed incoherently to yield an N-times improvement in the Doppler measurement of a s...

Full description

Saved in:
Bibliographic Details
Published in:Optics letters 2006-03, Vol.31 (6), p.826-828
Main Authors: Swann, W C, Newbury, N R
Format: Article
Language:English
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:We demonstrate a coherent lidar that uses a broadband femtosecond fiber laser as a source and resolves the returning heterodyne signal into N spectral channels by using an arrayed-waveguide grating. The data are processed incoherently to yield an N-times improvement in the Doppler measurement of a surface vibration. For N=6, we achieve a sensitivity of 153 Hz, corresponding to a 0.12 mm/s motion, in 10 ms despite a signal that is speckle broadened to 14 kHz. Alternatively, the data are processed coherently to form a range image. For a flat target, we achieve a 60 microm range resolution, limited mainly by the source bandwidth, despite the dispersion of 1 km of optical fiber in the signal path.
ISSN:0146-9592
DOI:10.1364/OL.31.000826