Electromagnetic near field measurements by using magnet garnet crystal.

An optical scanning electromagnetic field probe system consisting of an optic crystal substrate and a galvano scanner has been developed for high speed, low-invasive measurement of electromagnetic near field distribution. We measured magnetic field distributions above a microstrip line using several magnetic garnet crystal substrates and the probe system. We observed that the frequency response in the gigahertz range improved when we applied a magnetic bias to the crystal. In addition, a magnetic field component in a particular direction could be detected by controlling the direction of the magnetic bias. [ABSTRACT FROM AUTHOR]