Self-Absorption And Phonon-Assisted Radiative Energy-Transfer Processes In A Ruby-Laser Rod

Systematic investigations of the effect of self-absorption on the dynamic and steady-state spectroscopic properties in ruby have been carried out at different temperatures (from similar to 130 to 500 K) using a long, pink laser rod. At about 140 K, the lengthening of decay times of the R lines reached a maximum and then decreased with increasing geometric trapping. Spectral diffusion as large as 10 cm(-1) was observed in the complete-trapping regime. These observations suggest reexamination of the theoretical model for phonon-assisted radiative energy transfer in ruby