Stimulated emission from nitrogen-vacancy centres in diamond

Abstract

Stimulated emission is the process fundamental to laser operation, thereby producing coherent photon output. Despite negatively charged nitrogen-vacancy (NV−) centres being discussed as a potential laser medium since the 1980s, there have been no definitive observations of stimulated emission from ensembles of NV− to date. Here we show both theoretical and experimental evidence for stimulated emission from NV− using light in the phonon sidebands around 700 nm. Furthermore, we show the transition from stimulated emission to photoionization as the stimulating laser wavelength is reduced from 700 to 620 nm. While lasing at the zero-phonon line is suppressed by ionization, our results open the p..