Simultaneous Imaging of Static and Microwave Magnetic Field Distributions by Magneto Optical Indicator Microscopy

In this paper, we propose a method for the simultaneous imaging of static and microwave magnetic field distributions using magneto-optical indicator microscopy. This method employs an optical indicator made of a bismuth-substituted yttrium iron garnet (Bi1Y2Fe5O12; Bi-YIG) thin film coated with a metal thin film layer and visualizes field distributions using a polarized light optical microscope. The method utilizes the magneto-optical effect of the Bi-YIG thin film to detect static magnetic fields, while the thermo-chromatic effect of the Bi-YIG thin film, induced by microwave heating of the metal layer, enables the visualization of microwave magnetic fields. Experimental results demonstrate that this method can simultaneously visualize static and microwave magnetic fields with sensitivities of approximately 0.1 and 1.1 Gauss, respectively, for a 1 mm by 1 mm area.