Smart-cut 6H-silicon carbide (SiC) microdisk torsional resonators with sensitive photon radiation detection

This digest paper reports experimental demonstration of a new type of microdisk torsional resonators based on a smart-cut 6H-silicon carbide (6H-SiC) technology. We carefully calibrate the thermomechanical vibrations of these torsional-mode resonators by employing highly sensitive laser interferometric readout techniques, with displacement sensitivities (i.e., limits of detection) at the levels of S_x^1/2~0.1pmWHz and smaller. To utilize these first 6H-SiC torsional resonators, we further demonstrate sensitive detection of radiations from both blue (405nm) and infrared (IR 785nm) photons Toward force detection applications which torsional resonators are suitable, our measurements demonstrate an intrinsic force resolution of S_F^1/2≈5 7fN√Hz and a torque resolution of S_T^1/2≈3.7×10^-20 (N·m)√Hz, limited by the fundamental thermomechanical fluctuations.