IEEE Sensors
2016
Magnetic field sensor based on a single mode-multimode-single mode optical fiber structure
J. ASCORBE; J.M. CORRES; F.J. ARREGUI; I.R. MATÍAS

Abstract

A single mode-multimode-single mode structure (SMS) has been used for developing a magnetic field sensor without using magnetic fluids. The SMS optical fiber was coated with a magneto-optical material by means of sputtering. The sputtering process was monitored in order to achieve the optimum thickness of the coating and the best sensitivity. Sensitivities of 1.45 dB/T and 6 nm/T have been achieved. Repeatability in the fabrication and in the behaviour of the device has been checked.

Thin-Film Coating

The SMS optical fiber was introduced to the vacuum chamber of a Pulsed DC Sputtering System (Nadetech, Inc.). It offers the possibility of monitoring changes in the spectrum while the sputtering process is being done.

 

Keywords: Magnetic fields; Optical fibers; Optical fiber sensors; Periodic structures; Magnetic liquids; Sputtering; Single mode-multimode-single mode; SMS structure;  Optical fiber interference; Thin films; Magneto-optic materials.