Continuous-wave ultraviolet laser action in strongly scattering Nd-doped alumina

Abstract
We report electrically pumped, cw laser action near 405 nm from Nd3+-doped δ-alumina nanopowders. To our knowledge, this is the first report of stimulated emission from the high-lying F2-excited states, achieved through feedback from strong elastic scattering of light over transport path lengths shorter than half a wavelength.