Multimode fiber-optic Mach-Zehnder interferometric strain sensor

摘要

A multi-mode fiber-optic Mach-Zehnder interferometric strain sensor has been constructed in which interference field is much brighter than that of a single-mode fiber-optic interferometer. Several measures are taken on the basis of theoretical analysis. An interference pattern with excellent visibility has been obtained. Speckle effects have apparently been cut down. Stain coefficient and temperature coefficient are 1.17 $MUL 10$+7$/ rad/m and 72.4 fringes/(mK), respectively, and are in agreement with theory.