Ultra-long Brillouin optical time-domain analyzer based on distortion compensating pulse and hybrid lumped–distributed amplification

A Brillouin optical time-domain analysis (BOTDA) scheme based on hybrid amplification, consisting of a distributed Raman amplification and lumped provided by remotely pumped Erbium-doped fibers, is proposed thoroughly studied, enabling longest sensing distance among existing repeaterless techniques. First, the criteria for optimizing powers entering fiber are defined. Then, walk-off effect in forward associated self-phase modulation pointed out analyzed to describe BOTDA pulse distortion its impact balanced detection used relative intensity noise mitigation. compensating approach mitigate signal distortion, guaranteeing safe use an ultra-long sensor. The combination all approaches mentioned above validated two types loop configurations, with 150 200 km real remoteness, both constituting record-high performance each case.