ALL DIELECTRIC OPTICAL MAGNETOMETER

AN EFFORT TO DEMONSTRATE AN ALL DIELECTRIC OPTICAL MAGNETOMETER OF HIGH SENSITIVITY IS PROPOSED. THE CONCEPT IS BASED UPON THE DETECTION OF MAGNETIC FIELD INDUCED BIREFRINGENCE IN A PARAMAGNETIC MATERIAL HAVING A HIGH VERDET CONSTANT. THE PROPOSED SENSOR RELIES ON THE USE OF AN OPTRA DEVELOPED 2-FREQUENCY HELIUM NEON LASER, IN A COHERENT HETERODYNE DETECTION MODE, TO ACHIEVE A PHASE ANGLE RESOLUTION AT THE SHOT NOISE LIMIT. BY MULTIPASSING AND COOLING THE OPTICAL CELL, SENSITIVITIES APPROACHING OR EXCEEDING THOSE OF OTHER TECHNIQUES SHOULD BE REALIZABLE. THE INHERENT LARGE DYNAMIC RANGE OF THE SENSOR READ-OUT SHOULD MAKE THE SYSTEM WELL-SUITED FOR OPERATION IN A GRADIOMETER MODE. USING POLARIZATION MAINTAINING OPTICAL FIBERS WOULD ALLOW INTERROGATION OF A NETWORK OF SENSORS.