Efficient pumping of Nd3+ ions via change transfer bands of Fe3+ ions in YAG

Investigations were made of the spectroscopic and lasing energy characteristics of YAG:Nd:Fe laser crystals. A mechanism is proposed for energy exchange by excitation of iron ions to charge transfer bands. It is shown that pumping to the O^2 – →Fe³⁺ charge transfer band compensates largely for the drop in the efficiency of the active elements when the maximum of the spectral distribution of the flashlamps is shifted toward the ultraviolet.