High-efficiency DBA-BOTDA with optimized SNR by multiple bandwidths pump modulation

• 来源期刊: 中国光学快报（英文版）
• 年，卷（期）: 2019,（1）
• 页码范围: 16-21
• 页数: 6页
• 语种: 英文
• DOI: 10.3788/COL201917.010603

摘要

For Brillouin optical time-domain analysis (BOTDA) based on distributed Brillouin amplification (DBA),constant Brillouin response achieved by the exponentially variable bandwidth/intensity pump modulation suffers from the much lower pumping efficiency for long-range sensing,which counterbalances the merit of DBA.In this Letter,pump modulation by multiple constant bandwidths was proposed and demonstrated.The ～98.9 km sensing with ～5 m spatial resolution and no use of optical pulse coding (OPC) was achieved by ～8 dBm Brillouin pump,which is lower by ～9 dB in theory by comparison with exponentially increased bandwidth modulation.Compared with traditional DBA-BOTDA,signal-to-noise ratio (SNR) enhancement with ＞4.6 dB was obtained.The flattened standard deviation (STD) of Brillouin frequency shift (BFS) (less than ～2 MHz) along the whole fiber was demonstrated.