An optical modulator based on a single strongly coupled quantum dot--cavity system in a p-i-n junction.

We demonstrate an optical modulator based on a single quantum dot strongly coupled to a photonic crystal cavity. A vertical p-i-n junction is used to tune the quantum dot and thereby modulate the cavity transmission, with a measured instrument-limited response time of 13 ns. A modulator based on a single quantum dot promises operation at high bandwidth and low power.