Energy storage and heating measurements in flashlamp-pumped Cr:Nd:GSGG and Nd:YAG

The authors have experimentally measured the energy stored and the heat generated in flashlamp-pumped Cr:Nd:GSGG for three Cr/sup 3+/ concentrations in the range of 1-2*10/sup 20/ ions/cm/sup 3/. It has been found that the energy storage efficiency in these samples is 1.7 times greater than that of the Nd:YAG sample, and the normalized heating parameter chi , defined as the heat deposited per unit of stored energy, is 2.5 under the specified pumping conditions, with no evident dependence on the Cr/sup 3+/ concentration. It has been been found that the measured chi value for the sample of Nd:YAG is 2.9 for the same pumping conditions. These observed chi values exceed expected values by factors of approximately 1.1 and 2 for the Cr:Nd:GSGG and Nd:YAG samples, respectively. The thermal focal length in the two materials was measured showing that the lensing is shorter in GSGG by a factor of 2.6 for the same available output power, or a factor of 4.5 for the same input pump power. The expected thermal lensing was determined using measured heat loads with no adjustable parameters, achieving satisfactory agreement with measured lensing values.<
>