Room-temperature stimulated emission from AlN at 214 nm

We report the first ever room temperature (RT) stimulated emission at 214 nm using high quality AlN layers that were grown over patterned sapphire substrates by pulsed lateral epitaxial overgrowth (PLOG) process. The PLOG process yielded fully coalesced layers with total thicknesses in excess of 10 mu m resulting in a reduction in the threading dislocation density by several orders. The stimulated emission was achieved at 214 nm under pulsed optical pumping at RT. The RT threshold optical power density was approximately 9 MW/cm(2) and the stimulated edge-emission signal was strongly polarized with E parallel to c.