| MITIGATION OF THERMAL EFFECTS IN END PUMPING OF YAG/Nd:YAG LASER Rods, MODELLING AND EXPERIMENTS |
| Paper ID : 1118-ISCHU |
| Authors |
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Prof. Dr Reda M. El-Agmy * Department of physics, Faculty of science, Helwan University, Ain Helwan 11792-Cairo-Egypt |
| Abstract |
| In this work, we have presented a finite element (FE) numerical modelling simulations to study and analyze the thermal effects in Nd:YAG and composite YAG/Nd:YAG laser rods. We have calculated numerically the temperature distributions, stress intensity and thermal focal lengths at different pump powers and rod geometries for both Nd:YAG and composite YAG/Nd:YAG rods. The FE simulations showed that using composite laser rod of undoped cap reduces the maximum value of stress intensity and thermal focal length by about 35% and 50%, respectively. The focal lengths of thermally induced lens were calculated by integration across the laser rods of Optical path length (OPL). We have verified the FE calculations and the calculations of the focal lengths of thermally induced lens experimentally by direct measurement of focal length of thermally induced lens by using two independent techniques the Hartmann-Shack wavefront sensor and Mach-Zehnder interferometer. Good agreement was obtained between FE calculations and experimental measurements. |
| Keywords |
| Nd:YAG lasers, Thermal lens, Wavefront sensing, solid state lasers. |
| Status: Abstract Accepted (Oral Presentation) |