A measurement of a magnetic field vector-application of the magneto-birefringence effect by magnetic fluid

The measurement of a magnetic field vector using the magneto-birefringence effect in a magnetic fluid is discussed, and the characteristics of the experimental system are described. The system applies a laser diode and a thin film of magnetic fluid as a refracting element to measure magneto-birefringence. Magnetic fluids have both a large anomalous magneto-birefringence effect and a Faraday effect. These effects cause the change of intensity and the phase shift of a refracted laser beam. In the experimental system, a method for detecting these effects is proposed. On the basis of the experimental results, it is clear that the direction and the intensity of a two-dimensional magnetic field vector can be measured in the cases of both direct and alternating magnetic fields