ANALYSIS OF UNIDIRECTIONAL OPERATION OF KERR LENS MODE-LOCKED RING OSCILLATORS

The starting of Kerr lens mode-locking operation can be successfully u nderstood by a simple ABCD resonator analysis, which discards the diff ractive effects introduced by the hard aperture of the laser cavity. T hese effects are nevertheless important since they change the intracav ity beam shape and need to be considered to explain the observed unidi rectional operation in ring resonator configurations. We present a mod el analysis which, using a Gaussian apodizing aperture, rigorously inc ludes the diffraction of the circulating cavity eigenmode by the apert ure.