Passively Q-switched self-frequency-doubled Nd3+:GdCa4O(BO3)3 laser

The performance of a flash-lamp-pumped self-frequency-doubled Nd3+:GdCa4O(BO3)(3) (Nd:GdCOB) laser that is passively Q switched with Cr4+:YAG saturable absorbers is demonstrated. The maximum 0.53-mum pulse energy obtained is 2.6 mJ, and the maximum peak intensity is 15 MW/cm(2) The dependence of the pulse characteristics on the orientation of the saturable absorber and on the cavity length is measured. Meanwhile, the transversal distribution of the intracavity photon density is taken into account in the rate equations for an intracavity frequency-doubled passively Q-switched laser, and the solutions are used to account for the behavior of the passively Q-switched Nd:GdCOB laser. (C) 2001 Optical Society of America.