Share Email Print
cover

Proceedings Paper

Numerical analysis of linewidth demands in heterodyne lidar
Format Member Price Non-Member Price
PDF $17.00 $21.00
cover GOOD NEWS! Your organization subscribes to the SPIE Digital Library. You may be able to download this paper for free. Check Access

Paper Abstract

Coherent Doppler lidars (CDL) and coherent differential absorption lidars are widely applied in the measurements of atmospheric wind and constituents respectively. To improve the detection range of heterodyne lidars, the demands for laser linewidth are studied based on the statistical theory and Monte Carlo simulations. The signal to noise ratio (SNR) and the spectrum of intermediate frequency (IF) signal are analyzed under different laser power and linewidth. When the detection range is beyond the coherent length, the IF signal can still be measured, and the power spectrum of IF signal will be broadened, which results in the peak value decrease in the power spectrum. In heterodyne Doppler lidars, the frequency extraction errors of IF signal fluctuate with SNR. To realize the velocity measurement performance for wind and other moving targets, detection performances with various laser linewidth are analyzed according to the 3σ criterion. The calculations indicate that better results can be obtained with larger powers when the laser linewidth is relatively wider and that the effective detection range of lidar can be longer than the coherent length for lasers with certain linewidth. To verify the analysis, heterodyne experiments are carried out based on the fiber delay lines and fiber lasers with different linewidths, and the SNR is controlled by a variable optical attenuator. The results show that measurements with large laser power can reduce the errors caused by the power spectrum broadening of IF signal. The analysis may aid the determination of laser power and linewidth in heterodyne lidars.

Paper Details

Date Published: 23 October 2018
PDF: 8 pages
Proc. SPIE 10821, Advanced Sensor Systems and Applications VIII, 1082113 (23 October 2018); doi: 10.1117/12.2326907
Show Author Affiliations
Xiao Dong, National Univ. of Defense Technology (China)
Yihua Hu, National Univ. of Defense Technology (China)
Nanxiang Zhao, National Univ. of Defense Technology (China)
Xinying Zhao, National Univ. of Defense Technology (China)
Shilong Xu, National Univ. of Defense Technology (China)


Published in SPIE Proceedings Vol. 10821:
Advanced Sensor Systems and Applications VIII
Tiegen Liu; Shibin Jiang, Editor(s)

© SPIE. Terms of Use
Back to Top