Ultralow Threshold, Single-Mode InGaAs/GaAs Multi-Quantum Disk Nanowire Lasers

TL;DR

This paper reports the development of ultralow threshold, single-mode InGaAs/GaAs nanowire lasers operating in the near-infrared, with potential applications in integrated photonics and sensing.

Contribution

It introduces a novel nanowire laser design with minimized dimensions and passivation, achieving record low thresholds and stable single-mode operation at room temperature.

Findings

Threshold as low as 1.6 μJ/cm² at 5 K

Room temperature lasing with 48 μJ/cm² threshold

High quality factor exceeding 6400

Abstract

We present single-mode nanowire (NW) lasers with ultralow threshold in the near-infrared spectral range. To ensure the single-mode operation, the NW diameter and length are reduced specifically to minimize the longitudinal and transverse modes of the NW cavity. Increased optical losses and reduced gain volume by the dimension reduction are compensated by excellent NW morphology and InGaAs/GaAs multi-quantum disks. At 5 K, a threshold low as 1.6 {\mu}J/cm2 per pulse is achieved with a resulting quality factor exceeding 6400. By further passivating the NW with an AlGaAs shell to suppress surface non-radiative recombination, single-mode lasing operation is obtained with a threshold of only 48 {\mu}J/cm2 per pulse at room temperature with a high characteristic temperature of 223 K and power output of ~ 0.9 {\mu}W. These single-mode, ultralow threshold, high power output NW lasers are promising for the development of near-infrared nanoscale coherent light sources for integrated photonic circuits, sensing, and spectroscopy.