SPATIALLY-SELECTIVE BRILLOUIN DISTRIBUTED OPTICAL FIBER SENSOR AND SENSING METHOD USING BRILLOUIN SCATTERING WHICH ALLOWS SIMULTANEOUS SENSING OF MULTIPLE CORRELATION POINTS

摘要

A spatially-selective Brillouin distributed optical fiber sensor comprises: test optical fiber; a light source unit to use a modulation frequency to generate laser light; an optical modulation unit to use the laser light of the light source unit to generate a probe light signal and a pump light signal which is a pulse signal gated to have a time width determined based on the modulation frequency, and apply the pump light signal and the probe light signal to the test optical fiber from different directions; and a light detection unit to detect Brillouin scattering light generated by the pump light signal and the probe light signal in the test optical fiber, and divide the Brillouin scattering light in a time domain to calculate a Brillouin gain at a plurality of correlation points on the test optical fiber. Multiple correlation points are positioned within a measurement range and simultaneously used as measurement points to shorten measurement time of the entire range.