Microwave Power Imaging with Ferromagnetic Films Incorporated in Bimaterial Cantilevers
Thomas M. Wallis, John M. Moreland, Billy F. Riddle, Pavel Kabos
We report an imaging technique that uses ferromagnetic films incorporated in bimaterial cantilevers for spatially resolved calorimetric detection of microwaves emitted by sources of high frequency (4 to 20 GHz) radiation. The ferromagnetic film absorbs microwave power via eddy currents within the film and, in the presence of a biasing magnetic field, via ferromagnetic resonance. The resultant heating of the bimaterial cantilever leads to deflection that is detected by a laser beam-bounce method. Comparison of images acquired with and without a biasing magnetic field reveals sensitivity to the normal and tangential components of the magnetic field.