Sub-250 nm room-temperature optical gain from AIGaN/AIN multiple quantum wells with strong band-structure potential fluctuations

摘要

Deep-UV optical gain has been demonstrated in Al_(0.7)Ga_(0.3)N/AlN multiple quantum wells under femtosecond optical pumping. Samples were grown by molecular beam epitaxy under a growth mode that introduces band structure potential fluctuations and high-density nanocluster-like features within the AlGaN wells. A maximum net modal gain value of 118±9cm~(-1) has been measured and the transparency threshold of 5 ± 1μJ/cm~2 was experimentally determined, corresponding to 1.4 x 10~(17)cm~(-3) excited carriers. These findings pave the way for the demonstration of solid-state lasers with sub-250 nm emission at room temperature.