“…3,4 In particular, in the case of Cr 2+ : ZnSe, pulsed, 5 continuous wave, 6 and mode locked 7 operations have been demonstrated. 11,12 Combined with the recent understanding of charge transfer processes, these allow us to consider as possible in the future the realization of simple electrically pumped active nanocrystalline lasers. 8 Moreover, the most exciting developments in Cr 2+ : ZnSe lasers were, on the one hand, the recent demonstration of a RT laser based on Cr 2+ ion doped ZnSe nanopowders ͑with 200 nm grain size͒ ͑Refs.…”