Study On SBS Laser

Stimulated Brillouin scattering(SBS) is considered to 'be an effective approach for phase conjugation(PC) and increasing the brightness of Solid laser radiation. However maximal possible characteristics of lasers with PC have not been obtained yet. The problem of further improvement of PC quality is the complexity of the processes involved which complicates the detailed mathematical modeling and the applicable designing of laser.To solve these problems, closely and comprehensive study of PC at SBS in focused beams was performed at phase conjugation to develop a new generation of lasers of higher brightness. Main results are as follows:(1) The factors including parameter of focused beams and parameter of medium in effecting SBS threshold were analyzed in detail.(2) The factors in SBS conjugation fidelity and the methods to measuring fidelity were analyzed. Four examples of phase conjugation mirror based on SBS were studied. In addition, a brief analysis of the SBS phase conjugation resonator was achieved.(3) Process of SBS' generating whose effecting factors include the photo-life in the medium, the shape of pump pulse and the power density was theoretically studied. Numerical model and corresponding computer code for computational simulation of non-steady-state SBS wereelaborated based on a high-precision method of numerical integration, which is as near to reality as possible.(3) Properties of YAG laser Q-switching by SBS were experimentally investigated, and the laser without back reflective mirror was devised, and laser pulse was obtained at repetition rate IHz and 5Hz by optimizing lens focal length, length of cell and position of lens focal .point, resulting quality of PC is ideal.(4) After Cr4+:YAG has been added to the SBS YAG Laser, this laser was calculated numerically, and was experimentally studied. It has shown a good agreement with the theoretical results and proved that the appropriate combination of two passive Q-switch could enhance stability of the laser.