Title :
Design of Wide-Band Frequency Shift Technology by Using Compact Brillouin Fiber Laser for Brillouin Optical Time Domain Reflectometry Sensing System
Author :
Hao, Yunqi ; Ye, Qing ; Pan, ZhengQing ; Yang, Fei ; Cai, Haiwen ; Qu, Ronghui ; Zhang, Qinyuan ; Yang, Zhongmin
Author_Institution :
Shanghai Key Lab. of All Solid-State Laser & Appl. Tech., Shanghai Inst. of Opt. & Fine Mech., Shanghai, China
Abstract :
A novel wide-band optical frequency shift technology by using a compact single-frequency Brillouin fiber laser (BFL) configured with high-doped Er3+ fiber and high nonlinear fiber (HNLF) is proposed and investigated experimentally. By adjusting variable optical attenuator (VOA) to eliminate the free-running oscillation in the fiber ring cavity, a stable single-frequency BFL will be considered as local oscillator (LO) for coherent detection in Brillouin optical time domain reflectometry (BOTDR) sensing system. The BFL operates at 1549.06 nm red-shifted 0.084 nm (about 10.5 GHz) from the pump seed laser. The laser signal-to-noise ratio (SNR) is larger than 50 dB and the laser linewidth is about 3.1 kHz. Applying the BFL to the BOTDR system, the measured results show that the beat frequency between the spontaneous Brillouin scattering (SBS) and the LO is about 420 MHz and the frequency fluctuation is less than ± 2 MHz for 20-km sensing fiber.
Keywords :
Brillouin spectra; erbium; fibre lasers; fibre optic sensors; laser cavity resonators; optical attenuators; optical pumping; red shift; time-domain reflectometry; Brillouin optical time domain reflectometry sensing; beat frequency; coherent detection; compact Billouin fiber laser; compact single-frequency Brillouin fiber laser; distance 20 km; fiber ring cavity; frequency fluctuation; high-doped Er fiber; laser linewidth; laser signal-to-noise ratio; local oscillator; nonlinear fiber; pump seed laser; red shift; spontaneous Brillouin scattering; variable optical attenuator; wavelength 1549.06 nm; wide-band optical frequency shift technology; Fiber lasers; Laser excitation; Optical fiber sensors; Optical fibers; Pump lasers; Scattering; Brillouin fiber laser (BFL); Brillouin optical time domain reflectometry (BOTDR); distributed fiber sensor (DFS); wide-band optical frequency shift technology;
Journal_Title :
Photonics Journal, IEEE
DOI :
10.1109/JPHOT.2012.2213243
