ENHANCED PERFORMANCE OF ND LASER GLASS BY DOUBLE DOPING WITH CR

Cr and Cu offer the best possibilities of increasing the efficiency of Nd glass lasers. Unfortunately Cu must be discounted as it is pumped in the part of the UV which has to be blocked from the glass to prevent solarisation. Cr to Nd transfer is investigated by various methods. The classical method involving measuring lifetimes is shown to be misleading, at least for this pair of ions. A 45% efficient transfer from Cr to Nd was achieved, resulting in a glass of lower threshold and higher slope efficiency than pure Nd glass. A 35% increase in pumping efficiency was achieved.