Photonic crystal nanocavity laser with a single quantum dot gain

TL;DR

This paper reports a nanocavity laser driven by a single quantum dot, demonstrating low-threshold lasing and quantum dot contribution through photon correlation measurements, advancing quantum photonics integration.

Contribution

It introduces a photonic crystal nanocavity laser powered by a single quantum dot, showing low lasing thresholds and quantum dot-specific gain mechanisms.

Findings

Lasing begins at 42 nW under resonant conditions.

Photon correlation shows transition from anti-bunching to Poissonian.

Single quantum dot significantly contributes to the laser gain.

Abstract

We demonstrate a photonic crystal nanocavity laser essentially driven by a self-assembled InAs/GaAs single quantum dot gain. The investigated nanocavities contain only 0.4 quantum dots on an average; an ultra-low density quantum dot sample (1.5 x 108 cm-2) is used so that a single quantum dot can be isolated from the surrounding quantum dots. Laser oscillation begins at a pump power of 42 nW under resonant condition, while the far-detuning conditions require ~145 nW for lasing. This spectral detuning dependence of laser threshold indicates substantial contribution of the single quantum dot to the total gain. Moreover, photon correlation measurements show a distinct transition from anti-bunching to Poissonian via bunching with the increase of the excitation power, which is also an evidence of laser oscillation with the single quantum dot.