Microwave power imaging with ferromagnetic calorimeter probes on bimaterial cantilevers

We report a near-field microscope technique that uses a ferromagnetic film deposited onto a bimaterial cantilever for imaging of microwave power distributions. The bimaterial cantilever absorbs microwave power via the induction of eddy currents and, additionally, in the presence of a biasing magnetic field, via ferromagnetic resonance. The resultant heating of the cantilever leads to deflection that is detected by a laser beam-bounce method. Comparison of images of a microstrip resonator acquired with and without a biasing field indicates that eddy currents induced by the tangential component of the magnetic field play a significant role in cantilever heating.