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.
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.
基金
supported by the National Natural Science Foundation of China(NSFC)(No.61205079)
the Scientific Research Fund of Sichuan Provincial Education Department(No.18ZA0401)
