Abstract

Semiconductor microcavities with embedded optical gain medium are excellent system to study different regimes of light-matter interaction. Operating in the weak coupling regime, these system are frequently used as laser sources. Here, research has made tremendous progress in terms of miniaturization and efficiency, towards the ultimate goal of a thresholdless laser based on a single gain center. Research in this field has focused on the realization of high-β-microlasers which efficiently use spontaneous emission to reduce the threshold for the onset of stimulated emission, and on micro- and nanolasers based on a single quantum (QD) as gain medium [1]. In both cases, it is extremely difficult to unambiguously prove lasing when operating close to the limit of a thresholdless laser [2]. When operated in the strong coupling regime (cf. Fig 1a) [3], microcavities with a single QD (cf. Fig 1b) are of particular interest for a variety of applications in quantum information processing in particular due to non-classical effects such as single photon nonlinearities.

© 2015 IEEE