Title :
Simplified BOTDA System Based on Direct Modulation of a Laser Diode With an Extended Measurement Range
Author :
Jun Gi Hong ; Kwang Yong Song
Author_Institution :
Dept. of Phys., Chung-Ang Univ., Seoul, South Korea
Abstract :
We demonstrate a simplified Brillouin optical time-domain analysis system based on direct current modulation of a laser diode which is configured and optimized for long-range measurement. A precompensated low-frequency RF wave is applied for time-division generation of Brillouin pump and probe waves without using any microwave device. Low-speed frequency dithering of the laser diode is additionally applied for the suppression of the coherent noise originating from Rayleigh scattering of the leakage probe wave. In experiments, distributed measurements of Brillouin frequency shift along a 25 km single-mode fiber are presented with a spatial resolution of 1.2 m and measurement accuracy (σ) of 0.45 MHz, respectively.
Keywords :
Brillouin spectra; Rayleigh scattering; laser noise; laser variables measurement; light coherence; measurement by laser beam; optical fibre testing; optical modulation; semiconductor lasers; Brillouin frequency shift; Brillouin pump; Rayleigh scattering; coherent noise suppression; direct current modulation; distance 25 km; extended measurement range; laser diode; leakage probe wave; low-frequency RF wave precompensation; low-speed frequency dithering; probe waves; simplified BOTDA system; simplified Brillouin optical time-domain analysis system; single-mode fiber; spatial resolution; time-division generation; Frequency measurement; Frequency modulation; Optical fibers; Optical pumping; Probes; Scattering; Brillouin scattering; Modulation; Optical fiber measurement; modulation; optical fiber measurement;
Journal_Title :
Lightwave Technology, Journal of
DOI :
10.1109/JLT.2015.2394433
