Three-frequency chaotic instability in soft-aperture Kerr-lens mode-locked laser around 1/3-degenerate cavity configuration

Abstract

The quasi-periodic route to chaos from a three-frequency interaction was experimentally observed when the soft-aperture Kerr-lens mode-locked Ti:sapphire laser was operated in a cavity configuration that was around 1/3-degenerate, with non-zero group velocity dispersion. When the pump beam was smaller than the cold cavity beam, the laser oscillated among three frequencies, resulting in the modulation of phase-locked longitudinal modes. Increasing the pump power caused the nonlinear interaction of the three frequencies to induce a combination tones due to nonlinear gain and Kerr nonlinearity. Further secondary beating of these combinations tones at even higher pumping caused the system to become chaotic. Starting from the period-3 pulses in the 1/3-degenerate configuration, the quasi-periodic route to chaos was also observed when the configuration was tuned slightly away from degeneracy. (C) 2003 Elsevier B.V. All rights reserved.