Abstract

Optical-fiber interferometry has been studied and exploited in the area of fiber-optic sensors. The optical-fiber element has been shown to give a linear phase shift response to many physical perturbations over many orders of magnitude. Limitations of the interferometers response are usually governed by the demodulation scheme converting the optical phase shift to an electrical signal. However, dynamic ranges in excess of 10⁷ have been demonstrated.¹ The minimum detectable phase shift in the interferometer corresponds to path length changes of m. Thus the optical-fiber interferometer can serve as a highly sensitive means of measuring the magnetostrictive properties of magnetic materials. This capability has been further increased by recent advances in fiber-optic magnetic sensors,² which extends measurements to dc.³ Thus this technique allows a unique method of determining both the ac and do response of the material. Accurate characterization of the magnetostrictive properties of materials, as well as being intrinsically significant, is specifically important to the field of magnetic sensors.

© 1984 Optical Society of America