THERMAL EFFECTS IN ND-YAG SLABS 3D MODELING AND COMPARISON WITH EXPERIMENTS

In the design of a diode-pumped slab solid-state laser, the knowledge of the temperature distribution and the thermal lensing in the medium is very important when attempting to achieve high output power in the TEM00 mode. A general 3D analytical calculation is given of the temperature distribution in a slab of finite size, side-pumped by many laser diodes; the spatial distribution of the pump power is taken into account. An approximate thermal focal length is calculated from the temperature distribution. Three different ways of cooling the slab are treated and included in the model as boundary conditions. We derive general solutions of the heat distribution for each case of cooling. The test of the model includes numerical calculations applied to the case of our slab prototype and a comparison with experimental measurements is made.