Stimulated emission spectroscopy of concentrated lithium-neodymium phosphate glasses in4F3/2 →4I11/2 and4F3/2 →4I13/2 transitions

Spectral and laser investigations of concentrated lithium–neodymium phosphate glasses in a wide temperature range from 77 to 500 K are carried out in the 4F3/2 → 4I11/2 and 4F3/2 → 4I13/2 transitions. For the first time, using conventional lamp pumping, the laser action in both 4F3/2 → → 4I11/2 and additional 4F3/2 → 4I13/2 transitions of a phosphate glass with 100% concentration of Nd3+ ions is registered as well as for the concentration series of phosphate glasses. A temperature re-switching effect for lines and channels of stimulated emission is found. An explanation of this effect is given.