| The beam quality and the output power of slab lasers have been improved greatly due toits small thermal lensing and distortion effect. The slab laser becomes more and moreimportant in the research of solid state lasers. Different from rob lasers, the symmetry of slablaser exists only in two direction. So, the simulation algorithm of slabs is different fromthose of robs, which means the theoretical research of slabs would have strong guidingsignificance for the cavity design. With the progress of study on slab lasers in domestic andabroad, contrasting with the common simulation ways, we propose an Endo method for thesimulation of the output field mode of Nd:YAG slab lasers which include FFT algorithm.In this thesis, the lamp-pumped slab laser has been studied in the following aspects:(1) Adopt an Endo method which include FFT algorithm to simulate the cavity modeof slab lasers. Comparing with the experiment result, we show that this method is muchsuitable for the small type cavity;(2) Simulate the output light field of flat-flat cavity at different distances, calculate theoutput spot size and far field divergence angle in two direction using the second-momentmethod, thus deduce the mode number inside the cavity. The analog results are in reasonableagreement with experimental data in terms of the spot size and the diffusion tendency.(3) Calculate the M2factor of flat-flat cavity under different length which evaluates thepropagation characteristics of the output beam. The result shows that the beam qualitybecomes better, but the power-loss increases and the efficiency decreases, with the growth ofcavity length.(4) Simulate the output light field of plane-concave cavity. Comparing with flat-flatcavity, the spot size is larger and the light collimation is better, but the plane-concave cavityhas more higher-order mode number and its mode purity is worse. |
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