Electrically pumped AlGaN edge-emitting UV-B laser diodes grown by molecular beam epitaxy

TL;DR

This paper reports the development of an electrically pumped AlGaN UV-B laser diode grown by MBE, demonstrating lasing at 298.5 nm with low threshold current and spectral narrowing, advancing UV laser technology.

Contribution

First demonstration of an electrically pumped AlGaN-based UV-B laser diode grown by MBE with clear lasing characteristics.

Findings

Lasing at 298.5 nm achieved

Threshold current density of 3.4 kA/cm$^2$

Spectral narrowing with 0.2 nm FWHM

Abstract

Mid and deep ultraviolet (UV) laser diodes remain among the least explored devices in semiconductor optoelectronics, despite their importance for spectroscopy, biochemical sensing, disinfection, and emerging quantum photonics. Here, we demonstrate an electrically pumped AlGaN-based laser diode operating in the UV-B band (280-315 nm). The device is grown by molecular beam epitaxy (MBE) on single-crystal AlN substrate and fabricated in a ridge-waveguide geometry. The laser diode operates at 298.5 nm and exhibits a relatively low threshold current density of 3.4 kA/cm$^2$. Clear nonlinear light-current characteristics and pronounced spectral narrowing with a full-width-at-half-maximum (FWHM) of 0.2 nm are measured above threshold.