Optical Mapping of RF Field Profiles in Resonant Microwave Circuits

We demonstrate a technique for mapping the electric field profiles in resonant microwave circuits. Optical pumping of microwave circuits fabricated on semiconductor substrates is shown to result in a modulation of the load power dependent on the local electric field of the microwave signal in the resonant circuit. By reading out the modulation in transmitted signal as a function of the position of the optical excitation, for a range of driving frequencies, we are able to produce 2D images related to the microwave electric fields in our circuits. Images are generated for a range of resonator designs and compared to numerical simulations. The presented technique is analytically modeled for insight to the relationship between electric field and modulation signal.