Spatio-temporal Gaussian pulse dynamics in sub-10-fs lasers

Summary form only given. Recently, the spatio-temporal dynamics of Kerr-Lens-Modelocked (KLM) lasers has been studied using either a complete 3-D space-time modeling or various approximation schemes. Those simulations simultaneously include all linear and nonlinear effects in the laser on equal footing. More elementary models showing the scaling of system behaviour as a function of the system parameters qualitatively are of major importance for further improvements of these systems, e.g. to achieve even shorter pulses. 5 fs pulses have been achieved recently by introducing a second focus to increase the self-phase modulation in the cavity. Y. Chen et al. (1999) argued, that dispersion managed soliton formation in the laser is the dominant pulse formation process explaining already the shape of the generated pulses and the connection between pulse energy and pulse width, taking the actual dispersion management into account. In this paper, this model discussed is extended to include the spatial effects due to self-focusing and diffraction. The analysis shows that the system has again steady state solutions considering only the energy preserving effects. The KLM action stabilizing the pulse against gain filtering can be considered to be a perturbation to this dynamics.