Lasing from a Quantum-Dot-Like Buried Heterostructure in an InP Nanobeam Cavity

TL;DR

This paper demonstrates lasing from the smallest known buried heterostructure in an InP nanobeam cavity, showing potential for scalable quantum-dot-scale nanolasers despite fabrication challenges.

Contribution

It reports the first lasing from a quantum-dot-like buried heterostructure in an InP nanobeam cavity, with detailed analysis of threshold dependence on active volume.

Findings

Lasing observed from a (107 nm)^2 heterostructure.

Threshold as low as 57 nW, comparable to single quantum-dot nanolasers.

Surface etching does not prevent lasing despite potential nonradiative recombination.

Abstract

We report lasing from a lithographically defined buried heterostructure with an estimated lateral footprint of (107 nm)^2, embedded in an InP photonic-crystal nanobeam cavity. This represents the smallest laterally confined buried heterostructure gain region from which lasing has been observed. Despite etching of the active region during cavity definition and the associated risk of surface-related nonradiative recombination, optically pumped devices exhibit a clear lasing threshold and a narrow linewidth. By systematically varying the BH size, we investigate how the lasing threshold depends on the active volume under optical pumping. The estimated intrinsic threshold under ideal carrier injection is 57 nW, comparable to values reported for single quantum-dot nanolasers, highlighting the potential of quantum-dot-scale buried heterostructures as deterministic, scalable gain media for nanophotonic lasers.