Abstract
The theoretical results are presented from a model that has been developed to simulate the 3 μm laser transition in Er3+ -doped laser crystals. The rate equations for the seven lowest energy levels of Er:YAG, Er:YSGG, Er:YLF and Er:BAYF have been solved numerically for both continuous wave (cw) and pulsed (Q-switched and gain switched) laser operation with direct optical pumping into the 4I11.2 energy level. The dependence of slope efficiency on the Er3+ * concentration for each laser crystal was investigated for cw operation and the relative performance of Er(15%):YLF, Er(15%):BAYF, Er(50%):YAG and Er(50%):YSGG was compared for each mode of operation. The change in the slope efficiency of Er: YLF at high Er3+ concentration, due to additional multi-ion processes, was calculated for a wide range of rate coefficients. It was determined that the slope efficiency could be reduced by as much as 12% by these processes and thus could explain the reduction in the slope efficiency as determined experimentally for lasers using highly doped fluoride crystals as the gain medium.
Original language | English |
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Pages (from-to) | 1269-1284 |
Number of pages | 16 |
Journal | Journal of Modern Optics |
Volume | 45 |
Issue number | 6 |
Publication status | Published - Jun 1998 |
Externally published | Yes |