Citation
Wunderer, T.; Chua, C. L.; Yang, Z.; Northrup, J. E.; Johnson, N. M.; Garret, G. A.; Shen, H.; Wraback, M. Pseudomorphically grown UV-C photo-pumped lasers on bulk AlN substrates. Applied Physics Express. 2011; 4; 092101.
Abstract
Optically pumped ultraviolet lasers were fabricated on low-defect density bulk (0001) AlN substrates. The AlxGa1xN/AlyGa1yN hetero-structures were grown by metal-organic vapor phase epitaxy near atmospheric pressure. Time-resolved photoluminescence studies of the MQW emission show long decay times of 870 ps and 1.14 ns at 295 K and 14K, respectively, and confirm the high structural quality of the epitaxial layers. Laser resonators with a length of about 1mm were formed by cleaving the AlN crystal to obtain m-plane mirror facets. Lasing is demonstrated at a wavelength of 267 nm with a threshold power density as low as 126 kW/cm2 at room temperature. The laser emission was TE polarized.
