High-power, 0.83-GHz-repetition-rate tenth-order harmonic mode-locked GdVO₄/Nd:GdVO₄ laser under diode direct pumping

A high-power tenth-order harmonic mode-locked GdVO₄/Nd:GdVO ₄ laser is reported under diode direct pumping. Using the large third-order nonlinearity of Nd:GdVO₄, a Z-folded cavity was constructed for colliding pulse mode locking. The tenth-order harmonic mode-locked pulses were attributed to the colliding of the counter-propagating pulses induced by the Kerr self-focusing effects in the laser crystal, and the pulses were further modulated by a semiconductor saturable absorber mirror. At the absorbed pump power of 23.1 W, an average output power of 5.8 W in TEM ₀₀ mode was obtained with the repetition rate of 0.83 GHz and the pulse width of 30 ps, corresponding to an optical-optical efficiency of 25.1% and a slope efficiency of 37.1%, respectively.