The Study Of The Thermal Effects And Aberration Of Solid-state Laser

High power and good beam quality of solid laser has potential applications in modern industrial processing and scientific research, while the parameters of laser are affected by the dynamic thermal distortion caused by the thermal effect in solid state laser. As a result, it is necessary to study the dynamic aberration caused by the thermal effect in solid state laser to compensate for the dynamic thermal distortion.The main purpose of this thesis is to measure the aberration caused by thermal effect in the solid state laser by use of Shack-Hartmann wave front detector. The drawbacks in theoretical calculation are modified by comparison between the experimental results and the theoretical results. The thermal effect in the solid state laser and the aberration caused by thermal effects are analyzed. Firstly, it is assumed that the heat-intensity distribution is symmetrical. All kinds of thermal effects and the compensation methods were analyzed from the heat-conduction equation. Secondly, it is assumed that the heat-intensity distribution is forms of Taylor polynomial, and the distribution of temperature in the solid state laser was discussed. On the basis of the analysis of thermal effects, dynamic thermal distortion caused by thermal effects in the solid state laser is calculated and showed in the forms of aberration. Piston and Defocusing are merely included in the forms of aberration and the other forms of aberration is not existed.Experiment for the study of aberration in solid state laser is set up. By the analysis of results in the measurements of the aberration in solid state laser, the dynamic thermal distortion caused by the thermal effects in the solid state laser is obtained. The dynamic thermal distortion is showed with phase distortion in three dimensions and the forms of aberration is obtained, in which the defocusing is the primary form of aberration.The theoretical results and the experimental results are compared and the drawbacks in the theoretical calculations are discussed. In the theoretical calculation, the real heat-intensity distribution is not a symmetrical distribution and should be obtained in the practical calculation from the fluorescence distribution.