Efficient laser operation of diode-pumped Pr3+,Mg2+:SrAl12O19

We report on diode-pumped laser operation of Pr3+,Mg2+:SrAl12O19 at lasing wavelengths of lambda (L) = 724.4 nm, lambda (L) = 643.5 nm, and lambda (L) = 622.8 nm. Furthermore, the laser threshold could be reached in the green spectral range. By pumping the crystal longitudinally from each side with two polarization beam combined InGaN laser diodes, a total pump power of a parts per thousand 4 W was available. In the deep red spectral range, a maximum output power of 564 mW was achieved with a maximum slope efficiency of 50 % with respect to the absorbed pump power. The maximum possible internal losses were estimated to a parts per thousand 1 %. Beam quality factors M (2) were in the range of 1.2-1.5.