Vibration Disturbance Localization Using a Serial Array of Identical Low-Finesse Fiber Fabry-Perot Interferometers

An optical fiber sensor system for localization of a vibrational disturbance along the fiber is presented. The sensor system is based on a serial array of identical Fabry-Perot interferometers, formed directly in the single mode SMF-28e fiber by pairs of fiber Bragg gratings with reflectivity of 0.04% each. Interferometers were interrogated by an intensity modulated distributed feedback diode laser. We present a signal processing algorithm for localization of a disturbed interferometer and experimental results for a serial array of 14 in-fiber interferometers. Simple sensor configuration and the use of low-frequency components make it potentially inexpensive and suitable for applications where continuous monitoring for appearance of vibrations is required.