Coherent coupling dynamics in a quantum dot microdisk laser

TL;DR

This study uses luminescence intensity autocorrelation to explore the ultrafast coupling dynamics between quantum dots and a high-Q microdisk laser, revealing enhanced and suppressed emission rates and the onset of coherent coupling at lasing threshold.

Contribution

It provides new insights into the ultrafast coherent coupling mechanisms in quantum dot microdisk lasers using LIA spectroscopy.

Findings

Enhanced spontaneous emission rate for resonant QDs

Suppressed emission rate for non-resonant QDs

Onset of coherent coupling at lasing threshold

Abstract

Luminescence intensity autocorrelation (LIA) is employed to investigate coupling dynamics between (In,Ga)As QDs and a high-Q (~7000) resonator with ultrafast time resolution (150 fs), below and above the lasing threshold at T = 5 K. For QDs resonant and non-resonant with the cavity we observe both a six-fold enhancement and a 0.77 times reduction of the spontaneous emission rate, respectively. In addition, LIA spectroscopy reveals the onset of coherent coupling at the lasing threshold through qualitative changes in the dynamic behavior and a tripling of the resonant QD emission rate.