A diode-pumped efficient 2.05-mum Tm,Ho:GdVO(4) laser with high beam quality is reported. The cavity configuration was optimized for weakening influence of thermal effect to resonator stability and mode-coupling. A conversion efficiency of 46% and a slope efficiency of 50% were obtained with continuous-wave (CW) output power of 10.5 W at 77 K. A repetitively Q-switched laser also achieved 10.1 W of output power at 10 kHz. A beam quality factor of M(2) < 1.1 was measured by the traveling knife-edge method. In addition, the energy per pulse of 1.9 mJ was obtained at 5 kHz, corresponding to the peak power of 0.14 MW.

Acousto-optically Q-switched operation of Tm (5 at. %), Ho(0.5 at. %):GdVO4 laser was reported in this paper. The Tm,Ho:GdVO4 crystal was cooled by liquid nitrogen and end-pumped by a 13.6 W fiber-coupled laser diode at 794 nm. Average power of 3.9W was obtained at pulse repetition frequency (PRF) from 10 to 50 kHz, with corresponding to optical-to-optical conversion efficiency of 29 %, and slope efficiency of 35%. The highest energy per pulse of 1.1 mJ in 23 ns was achieved at 3 kHz with peak power of 46 kW.

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In this paper, we report a high efficient and high power continuous wave diode-pumped cryogenic Tm(5% at.), Ho(0.5% at.):GdVO 4 laser. One pumping source of Tm,Ho:GdVO 4 laser is a fiber-coupled laser diode with fiber core diameter of 0.4 mm and numerical aperture (N. A.) of 0.3, supplying 14.8 W power at 793.6 nm. Another fiber-coupled LD radiation wavelength is centered at 805 nm with 0.22 N.A. and the same core diameter delivering power of greater than 30 W. For input pump power of 13.6 W at 794.2nm, the maximum output power of 4.2W, optical-to-optical conversion efficiency of 31% and slope efficiency 38% have been attained at 2.048 µm. The maximum cw power of 7.9-W is achieved by 805 nm LD under power of 26 W, corresponding to 40% optical-optical conversion efficiency relative to absorbed pumping power, which is close to quantum limited efficiency of 2 µm laser.

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