Refractive index dynamics of InAs/GaAs quantum dots

Abstract

The refractive index dynamics of an InAs/InGaAs/GaAs dots-in-a-well semiconductor optical amplifier is calculated and compared with experimental results. The fast and slow recovery timescales together with the behaviour with increasing injection are reproduced and explained in terms of the density of carriers available in upper quantum dot and continuum states. Also, a Coulomb-mediated shift of the dot susceptibility is suggested as responsible for the fast recovery of the phase. (C) 2013 AIP Publishing LLC. (DOI: 10.1063/1.4813472

Ground-state lasing in high-power InAs/GaAs quantum dots-in-a-well laser using active multimode interference structure

“…Therefore, it is possible to suppress ES lasing using the active MMI-LD structure. As reported in [20,21], the refractive index of the QD active region n c is changed with injection carriers and temperature. However, this carrier induced refractive index is three times smaller in QD than that in QW.…”

Bistability of threshold in quantum dash‐in‐a‐well lasers

“…where k b is the Boltzmann constant, E b is the energy difference from the band edge of the well to the band edge of the barrier and T is the temperature [13], respectively. The temperature dependence of the transparency carrier density is included through the relation [14] N tr (T ) = N tr (300) * T 300 (9) At low temperatures, the calculated escape time is large enough to result in the carriers becoming localised in the upper layers because of the large ratio of the capture and the escape times; this causes saturable absorption.…”

“…We include a temperature dependence for the transparency carrier density, N tr , in order to account for the temperature dependence of the gain in (6). The escape time is calculated from where k b is the Boltzmann constant, E b is the energy difference from the band edge of the well to the band edge of the barrier and T is the temperature [13], respectively. The temperature dependence of the transparency carrier density is included through the relation [14] At low temperatures, the calculated escape time is large enough to result in the carriers becoming localised in the upper layers because of the large ratio of the capture and the escape times; this causes saturable absorption.…”