Optical magnetic-field sensor

摘要

The subject matter of the main application (Patent Application P 3726411.7-GR 87 P 3272 DE) is an optical magnetic-field sensor in which the magnetic-field-dependent Faraday rotation of the plane of polarisation of a linearly polarised light ray (10, 11) which propagates in an optical fibre, is measured by means of an arrangement with heterodyne reception and reciprocal light path. According to the invention, a light source (1) with a frequency-modulatable laser diode (40), which is associated with a Mach-Zehnder interferometer (52, 53, 54, 55), is provided for generating a linearly polarised light ray (2), the direction of polarisation of which rotates at a predetermined angular rate. <IMAGE>