An analytical treatment for the propagation of astigmatic Gaussian beams in Kerr media is presented. This method, which is valid to the first order in the beam power, allows us to calculate in closed form the nonlinear variations of the spot size and the radius of curvature. This formalism is applied to the calculation of the self-consistent Gaussian mode of an astigmatic resonator with a Kerr medium, such as those used for Kerr-lens mode-locked lasers. Theoretical predictions are confirmed by the experimental results obtained with a femtosecond Ti:sapphire laser. In particular, the design of an optimized resonator permits self-starting of the mode-locking mechanism.
© 1995 Optical Society of America
V. Magni, G. Cerullo, S. De Silvestri, and A. Monguzzi, "Astigmatism in Gaussian-beam self-focusing and in resonators for Kerr-lens mode locking," J. Opt. Soc. Am. B 12, 476-485 (1995)