Study On The Pulse Width Stability Of Stimulated Brillouin Scattering For KrF Laser

KrF laser has characteristics of short-pulse, high-efficiency, high-power and broad-frequency. It is applied to many fields in laser project, especially provided with promising potential in Inertia Confinement Fusion (ICF) study. And that short-pulse and less-divergence are required in ICF system, so we have to compress pulse width and improve beam quality. Stimulated Brillouin scattering (SBS) is an effective method used in laser pulse compression and beam quality improvement. Accordingly, study in stability of SBS pulse width pumped by a KrF laser, is important for whether SBS can be used to improve beam quality or not.In this dissertation, the pulse width stability of SBS pumped by a KrF laser as a rule of kinds of physical parameters is investigated theoretically and experimentally. The condition for obtaining steady pulse width is promoted.In theory, based on the coupled wave equation between the pump field, the Stokes field and the acoustic field in the SBS process, one-dimension theoretical model of SBS is constructed. SBS pulse width and its stability are numerically simulated. The rule of SBS pulse width and stability versus parameter of medium and pump power are obtained.In experiment, the pulse width and stability of SBS pumped by a KrF laser were investigated. The functions of SBS pulse width and stability versus pressure of medium, pump power and focus length are obtained. With the comparison to numerically simulation, the results indicate that in the condition of high-pressure, comparatively high power and mid-short focus length, the steady SBS pulse width is obtained.