Abstract
An analytical solution for soft-aperturing Kerr-lens mode locking (KLM) of compact non-astigmatic three-element resonators is derived using non-linear
ABCD ray matrix method. It is directly applicable to any three-element resonator configuration. General properties of compact resonators and the dependence of the Kerr non-linear strength on the resonator parameters are discussed. Selection guidelines on non-linear crystal length, focal length of the focusing element, and other cavity parameters for effective KLM are provided.
