Ultraviolet AlGaN multiple-quantum-well laser diodes

Abstract
We demonstrate ultraviolet emission from current-injection AlGaN multiple-quantum-well laser diodes grown on sapphire substrates by metalorganic chemical vapor deposition. Lasing was obtained in gain-guided laser diode test structures with uncoated facets and cavity length ranging from 400 to 1500 μm. Under pulsed bias conditions, threshold current densities as low as 23 kA/cm 2 have been achieved for laser diodes with emission wavelengths between 359.7 and 361.6 nm. The maximum output power was 45 mW per facet with differential quantum efficiencies of 1.3%.