Wideband Magnetooptic Probe with 10 µm-Class Spatial Resolution

Abstract

In this paper we give the results of the trial fabrication and basic performance evaluation of the fiber-edge magnetooptic (FEMO) probe with an approximately 10-µm-thick magnetooptic (MO) crystal. It utilizes the Faraday effect during rotational magnetization in a MO crystal for magnetic field sensing. One should note that as compared to a previously reported FEMO probe, the spatial resolution was improved keeping the similar measurable bandwidth. The developed probe had a 10-µm-class spatial resolution as well as a measurable bandwidth of approximately 2.5 GHz. Furthermore, the realization of this probe made it possible to perform GHz-range magnetic near-field mappings over a fine meander circuit, which means that one can visualize fine current distributions in this frequency range. We compared the measured magnetic field maps with the simulated ones obtained using an electromagnetic field simulator for analyses of GHz-range electromagnetic field distributions. As a result, it was found that sufficiently precise near-field distributions could be measured due to the low invasiveness and superior spatial resolution of the probe.