DIODE-PUMPED YTTERBIUM-DOPED SR-5(PO4)(3)F LASER PERFORMANCE

The performance of the first diode-pumped Yb3+-doped Sr-5(PO4)(3)F (Yb :S-FAP) solid-state laser is discussed. An InGaAs diode array has been fabricated that has suitable specifications for pumping a 3 x 3 x 38 mm Yb:S-FAP rod, The saturation fluence for diode pumping was deduced to be 5.5 J/cm(2) for the particular 2.8 kW peak power diode array uti lized in our studies, This is 2,5x higher than the intrinsic 2.2 J/cm( 2) saturation fluence as is attributed to the 6.5 nm bandwidth of our diode pump array, The small signal gain is consistent with the previou sly measured emission cross section of 6.0 x 10(-20) cm(2), obtained f rom a narrowband-laser pumped gain experiment, Up to 1.7 J/cm(3) of st ored energy density was achieved in a 6 x 6 x 44 mm Yb:S-FAP amplifier rod, In a free running configuration, diode-pumped slope efficiencies up to 43% (laser output energy/absorbed pump energy) were observed wi th output energies up to similar to 0.5 J per 1 ms pulse, When the rod was mounted in a copper block for cooling, 13 W of average power was produced with power supply limited operation at 70 Hz with 500 mu s pu lses.