Abstract

We report electrically pumped, cw laser action near 405 nm from ${\mathrm{Nd}}^{3+}$-doped $\delta$-alumina nanopowders. To our knowledge, this is the first report of stimulated emission from the high-lying ${}^{2}F$-excited states, achieved through feedback from strong elastic scattering of light over transport path lengths shorter than half a wavelength.

© 2002 Optical Society of America