Performance improvement of optical fiber sensor based on phase sensitive optical time domain reflectometry

Phase-sensitive optical time-domain reflectometry (phi-OTDR) has the advantages of high accuracy, large dynamic range and wide measurement range. It is suitable for remote monitoring of signals generated by external interference, and has broad prospects and great application potential. Nowadays, the requirements for its performance are increasing, and more and more scholars start to focus on the specific optimization of phi-OTDR system for different practical application. The contents of this paper are as follows: (1) The first part introduces the research results of phi-OTDR system in vibration signals measurement in recent years. Taking the signal-to-noise ratio (SNR) as the index, the solutions to the problems of system noise, laser frequency drift and signal fading are described; (2) The second part introduces the research results of phi-OTDR system in signal recognition capability in recent years. Taking recognition rate and nuisance alarm rate (NAR) as the indicators, the development of feature extraction and signal classification are described; (3) The third part introduces the research results of phi-OTDR system on the expansion of the detectable space in recent years. Taking the sensing distance as the index, the study of sensing distance and spatial positioning are described. The traditional phi-OTDR technology has been mature, and further improvement of performance will pave the way for further expansion and application of phi-OTDR system for different engineering fields in the future.