We report a sub-250-nm, optically pumped, deep-ultraviolet laser using an Al x Ga 1-x N-based multi-quantum-well structure grown on a bulk Al-polar c-plane AlN substrate. TE-polarization-dominant lasing action was observed at room temperature with a threshold pumping power density of 250 kW/cm 2 . After employing high-reflectivity SiO 2 /HfO 2 dielectric mirrors on both facets, the threshold pumping power density was further reduced to 180 kW/cm 2 . The internal loss and threshold modal gain can be calculated as 2 cm -1 and 10.9 cm -1 , respectively.
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)