Challenges to realizing deep-UV AlGaN-based lasers

Optical sources that emit in the deep-UV spectral regime have applications that include chemical/biochemical detection, water purification, surface decontamination, medical diagnostics and treatment, non-line-of-sight communication, and materials curing. A particularly challenging application is for a deep-UV laser source to enable point-of-need identification of bio-chemicals by Raman spectroscopy, which requires select wavelengths (<240nm), high power, and high beam quality in a compact, rugged system. The AlGaN semiconductor material system offers a promising path to realizing such a system, with direct access to the emission wavelengths of interest and demonstrated growth of multi-quantum-well heterostructures of high crystalline quality.