High Performance Distributed Acoustic Sensor Using Cyclic Pulse Coding in a Direct Detection Coherent-OTDR

摘要

We propose and experimentally demonstrate a Distributed Acoustic Sensor exploiting cyclic Simplex coding in a phase-sensitive OTDR on standard single mode fibers based on direct detection. Suitable design of the source and use of cyclic coding is shown to improve the SNR of the coherent back-scattered signal by up to 9 dB, reducing fading due to modulation instability and enabling accurate long-distance measurement of vibrations with minimal post-processing.