Non-local effect in Brillouin optical time-domain analyzer based on Raman amplification

作者：Jia Xinhong^*; Rao Yunjiang; Wang Zinan; Zhang Weili; Ran Zengling; Deng Kun; Yang Zixin

来源：High Power Laser and Particle Beams, 2012, 24(7): 1667-1671.

DOI：10.3788/HPLPB20122407.1667

• Brillouin
• Brillouin frequency shifts
• Brillouin pump
• Coupled equation
• Effective interactions
• Measurement accuracy
• Non-local effect
• Nonlocal
• Optical power
• Probe light
• Probe waves
• Pump depletion
• Raman amplification
• Raman pump
• Sensing fibers
• Sensing ranges
• System errors
• Time domain

Compared with conventional Brillouin optical time-domain analyzer (BOTDA), the BOTDA based on Raman amplification allows longer sensing range, higher signal-to-noise ratio and higher measurement accuracy. However, the non-local effect induced by pump depletion significantly restricts the probe optical power injected to sensing fiber, thereby limiting the further extension for sensing distance. In this paper, the coupled equations including the interaction of probe light, Brillouin and Raman pumps are applied to the study on the non-local characteristics of BOTDA based on Raman amplification. The results show that, the system error induced by non-local effect worsens with increased powers of probe wave and Raman pump. The frequency-division-multiplexing (cascading the fibers with various Brillouin frequency shifts) and time-division-multiplexing (modulating both of the Brillouin pump and probe lights) technologies are efficient approaches to suppress the non-local effect, through shortening the effective interaction range between Brillouin pump and probe lights.

• 出版日期2012
• 单位电子科技大学