Photon-level tuning of photonic nanocavities

Abstract

Energy-efficient optical control of photonic device properties is crucial for\ndiverse photonic signal processing. Here we demonstrate extremely efficient\noptical tuning of photonic nanocavities, with only photon-level optical energy.\nWith a lithium niobate photonic crystal nanocavity with an optical Q up to 1.41\nmillion and an effective mode volume down to 0.78$(\\lambda/n)^3$, we are able\nto achieve a resonance tuning rate of about 88.4~MHz/photon (0.67~GHz/aJ),\nwhich allows us to tune across the whole cavity resonance with only about 2.4\nphotons on average inside the cavity. Such a photon-level resonance tuning is\nof great potential for energy-efficient optical switching, wavelength routing,\nand reconfiguration of photonic devices/circuits that are indispensable for\nfuture photonic interconnect.\n