Self-Mixing Demodulation for Coherent Phase-Sensitive OTDR System
Open Access
- 12 May 2016
- Vol. 16 (5), 681
- https://doi.org/10.3390/s16050681
Abstract
Phase-sensitive optical time domain reflectometry (Ф-OTDR) attracts much attention due to its capability of telling the type and position of an intrusion simultaneously. In recent decades, coherent Ф-OTDR has been demonstrated to realize long-distance detection. For coherent Ф-OTDR, there are three typical demodulation schemes in the reported studies. However, they still cannot realize real-time monitoring to satisfy practical demands. A simple and effective demodulation method based on self-mixing has been put forward to demodulate the beat signal in coherent Ф-OTDR. It not only saves a local electrical oscillator and frequency locked loop, but also demodulates the beat signal without residual frequency. Several vibrations with different frequency were separately applied at the same location of a 42.5 km fiber. The spatial resolution of 10 m and frequency response range from 8 Hz to 980 Hz have been achieved. The precise location with signal-to-noise ratio of 21.4 dB and broadband measurement demonstrate the self-mixing scheme can demodulate the coherent Ф-OTDR signal effectively.Keywords
This publication has 16 references indexed in Scilit:
- Phase-sensitive optical time-domain reflectometry amplified by gated Raman pumpPhotonic Sensors, 2015
- Long-haul and high-resolution optical time domain reflectometry using superconducting nanowire single-photon detectorsScientific Reports, 2015
- Ultra-long phase-sensitive OTDR with hybrid distributed amplificationOptics Letters, 2014
- Ultra-long high-sensitivity Φ-OTDR for high spatial resolution intrusion detection of pipelinesOptics Express, 2014
- Coherent Noise Reduction in High Visibility Phase-Sensitive Optical Time Domain Reflectometer for Distributed Sensing of Ultrasonic WavesJournal of Lightwave Technology, 2013
- High Sensitivity Distributed Vibration Sensor Based on Polarization-Maintaining Configurations of Phase-OTDRIEEE Photonics Technology Letters, 2011
- Field test of a distributed fiber-optic intrusion sensor system for long perimetersApplied Optics, 2007
- Distributed fiber-optic intrusion sensor systemJournal of Lightwave Technology, 2005
- Real-time long range complementary correlation optical time domain reflectometerJournal of Lightwave Technology, 1989
- Optical time domain reflectometerApplied Optics, 1977