Achievement

The realization of an all-optical transistor where one ‘gate’ photon controls a ‘source’ light beam, is a long-standing goal in optics. By slowing and stopping a light pulse in an atomic ensemble contained inside an optical resonator, a team led by iQuISE faculty member Vladan Vuletic, with iQuISE trainee Kristin Beck, have realized a device in which one stored gate photon controls the resonator transmission and reflection of subsequently applied source photons. One stored gate photon attenuates the resonator transmission by a factor of 6, and can be retrieved from the atomic ensemble at 60% reduced probability after switching about 2 source photons. Without retrieval, the one-photon transistor can operate at much larger gain exceeding 1000 source photons per gate photon. This work opens up new perspectives for realizing deterministic interactions between individual photons in separate modes.