Micro-displacement sensor combined with a fiber ring interrogated by an optical time-domain reflectometer

Abstract

A micro-displacement sensing head based on two aligned cleaved fibers inserted into an optical fiber ring and interrogated by an OTDR is presented. The sensor configuration is characterized for measuring both longitudinal and axial microdisplacement, showing a sensitivity of 0.07 dB/mm and 2.67 dB/mm for longitudinal and axial micro-displacement, respectively. A multiplexing system using two of these configurations is also studied.