Analysis of a self QQ-switched mode-locking cc-cut Nd : GdV O4 /KTP green laser

A diode-pumped self QQ-switched mode-locking intracavity frequency doubled cc-cut Nd:GdV O4/KTP green laser is presented. The self-mode-locking is self-starting and stable. About 100% modulation depth for the self-mode-locked green pulses has been achieved. Using the hyperbolic secant function methods and the theory of Kerr-lens mode-locking, considering the Kerr-lens effect of gain medium, the cascading of second-order nonlinearities of KTP crystal, and also the influences of continuous pump rate, the stimulated-radiation lifetime of the active medium, we give a developed rate equation model for self QQ-switched and mode-locked laser. For this developed model, the theoretical evaluations are in good agreement with the experimental results and the width of the mode-locked green pulse was estimated to be about 210 ps.