Experimental research on all polarization maintaining fibre magnetostrictive sensor

Abstract

The structure and experimental results of an all polarization maintaining optical fibre magnetostrictive sensor are reported in this paper. The sensing head, an all polarization maintaining optical fibre Michelson interferometer with the sensing arm jacketed with 2 µm thick and 5 cm long TbDyFe film, is packaged in a polyurethane tube 15 mm in diameter and 60 mm in length. When the sensor is used to measure magnetic field up to 17 mT at the frequency of 1 kHz with 60 mT dc biasing magnetic field, the linearity of the response is better than 1% and the noise-equivalent magnetic field reaches 2 × 10−8 T Hz−1/2.