Photonic crystal nanolasers with controlled spontaneousemission

摘要

Optical microcavities offer the ability to create extremely low-threshold lasers with high modulation bandwidth. In such microcavity devices, the fraction β of spontaneous emission into the lasing mode can become close to one and the step-like "threshold" gradually disappears. To implement such high-β devices, one can exploit Cavity Quantum ElectroDynamics effects, more precisely spontaneous emission enhancement. The concomitant effect of the spontaneous emission acceleration is the preferential funnelling of spontaneous emission into the cavity mode. In our work, the cavity is a double-heterostructure cavity etched on a suspended membrane and contains In As quantum dots. Lasing is achieved with β-factors higher than 0.44 and is sustained by less than 10 quantum dots.