29 November 2011 Analysis of bandwidth-reduced local oscillator in Brillouin optical time domain reflectometry
Author Affiliations +
Proceedings Volume 8311, Optical Sensors and Biophotonics III; 831120 (2011) https://doi.org/10.1117/12.904179
Event: SPIE/OSA/IEEE Asia Communications and Photonics, 2011, Shanghai, China
Abstract
A local oscillator for coherent detection of backward Brillouin scattering in Brillouin optical time domain reflectometry (BOTDR) has been analyzed. A ring Brillouin fiber laser, whose Brillouin gain media is 70m high-nonlinear-fiber (HNLF), is used as local oscillator of coherent detection. The BFL operates at 1549.06nm red-shifted 0.084nm from the pump laser. As to Brillouin light, The detection frequency is reduced from ~11GHz of direct detection to ~420MHz of heterodyne detection in this paper. Self-lasing cavity-modes of BFL impose the "burr" intervalled at 2.5MHz on the frequency domain analysis of the beat-frequency siganl. Signal-to-noise ratio (SNR) of beat-frequency signal decreases greatly, resulting to Lorentzian fitting with error. By adjusting variable optical attenuator (VOA) to increase the cavity loss in the fiber ring cavity, the self-lasing cavity-modes will be eliminated and a stable Brillouin laser will be obtained. The frequency estimation accuracy is improved greatly.
© (2011) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Yun-Qi Hao, Yun-Qi Hao, Qing Ye, Qing Ye, Zheng-qing Pan, Zheng-qing Pan, Hai-wen Cai, Hai-wen Cai, Rong-hui Qu, Rong-hui Qu, } "Analysis of bandwidth-reduced local oscillator in Brillouin optical time domain reflectometry", Proc. SPIE 8311, Optical Sensors and Biophotonics III, 831120 (29 November 2011); doi: 10.1117/12.904179; https://doi.org/10.1117/12.904179
PROCEEDINGS
7 PAGES


SHARE
Back to Top