Light-controlled microwave whispering-gallery-mode quasi-optical resonators at 50W LED array illumination

We present experimental observations of light-controlled resonance effects in microwave whispering-gallery-mode quasi-optical dielectric-semiconductor disk resonators in the frequency band of 5 GHz to 20 GHz arising due to illumination from a light emitting diode (LED) of 50W power range. We obtain huge enhancement of photo-sensitivity (growing with the resonator Q-factor) that makes light-microwave interaction observable with an ordinary light (no laser) at conventional brightness (like an office lighting) in quasi-optical microwave structures at rather long (centimeter-scale) wavelength. We also demonstrate non-conventional photo-response of Fano resonances when the light suppresses one group of resonances and enhances another group. The effects could be used for the optical control and quasi-optical switching of microwave propagation through either one or another frequency channel. © 2015 Author(s)