Optical fiber acoustic sensor with improved acoustic signal measurement sensitivity

Abstract

The present invention relates to an optical fiber acoustic sensor with improved acoustic signal measurement sensitivity, and includes: a light source unit that generates and outputs pulsed light; an optical circulator that outputs the pulsed light output from the light source unit and input to an input terminal through an output terminal, and outputs light incident reversely from the output terminal through a detection terminal; a sensing optical fiber connected to the output terminal of the optical circulator and installed to extend over a measurement target region; at least one acoustic focusing member having the sensing optical fiber wound thereon multiple times, arranged in a measurement target region and adapted to focus an external acoustic signal; a light detection unit that detects Rayleigh scattered light scattered in the sensing optical fiber and traveling reversely; and a signal processing unit that control generation of the pulsed light by the light source unit and measures a vibration frequency and an intensity of acoustic received through the sensing optical fiber from a signal detected by the light detection unit, based on an output time point of the pulsed light.

Dependencies are inferred from the claim text.