Micro-displacement sensor using a Mach-Zehnder interferometer with long-period gratings

Abstract

We present the fabrication and characterization of a micro-displacement sensor using Mach-Zehnder interferometer in conventional optical fiber SMF28-e. The Mach-Zehnder interferometer uses a configuration of two long-period gratings (LPG) in series mechanically induced. The Mach-Zehnder interferometers were made to operate in the region of 1300 nm. As a result the interferometers were obtained with transmission bands with a bandwidth of 2 nm, extinction ratio of 12 dB and insertion loss of 2 to 3 dB. The characterization of the interferometer was found to be measured displacements up to 500 μm with a resolution of 7 microns, which envisions potential applications of micro-displacement sensor in the measurement of micro-deformations.