Excitonic lasing of strain-free InP(As) quantum dots in AlInAs microdisk

TL;DR

This study demonstrates excitonic lasing in strain-free InP(As) quantum dots embedded in AlInAs microdisks, revealing their optical properties, lasing behavior, and potential for integrated photonics.

Contribution

It reports the first observation of excitonic lasing in strain-free InP(As) quantum dots within microdisk cavities, including detailed characterization and lasing parameters.

Findings

Quantum dots emit at ~940 nm with strong temperature quenching.

Lasing occurs in whispering gallery modes with Q up to 13000.

Threshold for lasing is approximately 50 W/cm².

Abstract

Formation, emission and lasing properties of strain-free InP(As)/AlInAs quantum dots (QDs) embedded in AlInAs microdisk (MD) cavity were investigated using transmission electron microscopy and photoluminescence (PL) techniques. In MD structures, the QDs having nano-pan-cake shape have height of ~2 nm, lateral size of 20-50 nm and density of ~5x109 cm-2. Their emission observed at ~940 nm revealed strong temperature quenching, which points to exciton decomposition. It also showed unexpected type-I character indicating In-As intermixing, as confirmed by band structure calculations. We observed lasing of InP(As) QD excitons into whispering gallery modes in MD having dimeter ~3.2 mkm and providing free spectral range of ~27 nm and quality factors up to Q~13000. Threshold of ~50 W/cm2 and spontaneous emission coupling coefficient of ~0.2 were measured for this MD-QD system.