Cavity-assisted all-optical photodetection

Abstract

The free-carrier dispersion effect - which is resonantly enhanced by a cavity's quality factor to mode volume ratio Q/V[subscript eff] - enables ultrafast, energy-efficient, all-optical control of semiconductor resonators. When applied to recently developed photonic crystal cavities with record-high Q/V[subscript eff] values, this enhanced light-matter interaction unveils new possibilities in nonlinear optics. Here, by considering the free-carrier dispersion effect at the limit of a single photoexcited charge carrier pair, we analyze the possibility of realizing room-temperature, all-optical single photon detection.