Multiphoto Reduction Of Sm3+ To Sm2+ In A Zncl2 Based Glass

Persistent multiphoton reduction of Sm3+ to Sm2+ was observed for a transparent and colourless Sm3+ doped ZnCl2 based glass at room temperature. The difference in the absorption spectrum of the glass before and after irradiation of a focused infrared femtosecond pulsed laser showed that a proportion of the Sm3+ ions in the focused part of the laser inside the glass were reduced to Sm2+ ions after laser irradiation. It is suggested that Sm3+ ions act as electron trapping centres while active sites in the glass matrix act as holetrapping centres leading to the formation of Sm2+ ions.