Related Experiment Video
Updated: Jul 6, 2026

Spectral and Angle-Resolved Magneto-Optical Characterization of Photonic Nanostructures
Published on: November 21, 2019
Small optical magnetic-field sensor that uses rare-Earth iron garnet films based on the faraday effect
1Multimedia Systems Research Laboratory, Matsushita Electric Industrial, 3-1-1 Yagumo-nakamachi, Moriguchi, Osaka 570-8501, Japan.
Abstract:
Highly accurate optical magnetic-field probe sensors that use iron garnet films have been developed. New probe-type sensors were designed with a confocal optical system. A new garnet composition, Bi(0.98)Gd(0.92)La(0.03)Y(1.07)Fe(4.72)Ga(0.28)O(12), was found that shows high temperature stability for a sensitivity of less than 2.0% from -20 to +80 degrees C. The linearity error of the sensor output was within 1.0% for alternating magnetic fields from 0.3 to 42 mT. An optical current transformer that uses the proposed sensor has an ac linearity of 1.0% for input current up to nearly 300 A. The sensor realized high performance in actual use.
Related Concept Videos
Ferromagnetism
Eddy Currents
Other major applications of eddy currents appear in metal detectors and the braking systems of trains and roller...
Faraday's Law
Magnetic Damping
If, however, the bob is a slotted metal plate, the magnet produces a much smaller effect. When a slotted metal plate enters the field, an emf is induced by the change in flux; however, it is less effective because the slots limit the...
Magnetism
An individual magnetic pole cannot be isolated. No matter how small, every piece of a magnet contains a north pole and a south...
Faraday Disk Dynamo
