Efficient High Power Ho,Tm:GdVO₄ Laser

We report a 22.3 W cw diode-pumped cryogenic Ho(0.5at.%),Tm(at.5%):GdVO₄ laser at a wavelength of 2.05 µm. It is pumped by two fiber−coupled laser diodes with a fiber core diameter of 0.4 mm, both of which provide 42 W pump power near 802 nm. A cw output power of 22.3 W was obtained at the pump power of 51.0 W, corresponding to an optical-to-optical conversion efficiency of 43.7% when the ratio of the pump beam to oscillating laser beam in the crystal was ∼1.33:1. The M² factor was found to be 2.0 under an output power of 16.5 W.