High-power laser beam characterization

摘要

Abstract: The propagation characteristics of several beam radius definitions have been investigated analytically, numerically, and experimentally with regards to their applicability for high power solid state lasers with stable and unstable resonators and to the measurement with CCD cameras. Only for the second-moment radius a propagation law can be derived, which is valid for arbitrary partially coherent, paraxial beams. The same propagation law can be applied to the more useful power-content radius definition solely in the case of beams with non-varying profile such as produced by stable multi-mode resonators. For beams with varying profiles (such as produced by lasers with unstable resonators) a method is presented that allows the estimation of power-content radii behind cylindrical ABCD systems. !13