Bifurcation of fundamental Gaussian modes in Kerr-lens mode-locked lasers

Abstract

We propose that more than one spatial fundamental Gaussian mode may occur in concentric and confocal resonators under persisting nonlinear effect. Extensively studying the influence of the resonator's parameters in a Kerr-lens mode-locked resonator, pitchfork bifurcation results in more symmetrical configurations, and saddle-node bifurcation appears as the symmetry being broken. From the properties of bifurcation, we suggest that the equal-arm and near-confocal resonator is suitable for the emergence of bistability in Kerr-lens mode-locked lasers. (C) 1999 Elsevier Science B.V. All rights reserved.