Mode-locking and transverse mode dynamics in vertical external cavity surface-emitting lasers

An approach for passive mode-locking in multiple transverse-mode vertical external-cavity surface-emitting laser (VECSEL) is proposed. A definite phase relationship between the longitudinal and transverse modes in Z-cavity geometry cause the laser light to be produced a train of pulses with Gaussian transverse shape. Bifurcations responsible for the appearance and breakup of the mode locking regime are studied numerically.