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**3** plus concentrations in the range of 1-2 multiplied by 10**2**0 ions/cm**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**3** plus concentration. It has also 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 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.