INFRARED-LASER PERFORMANCE AND SELF-FREQUENCY DOUBLING OF ND3-GDCOB)(CA4GDO(BO3) (3)(ND)

Gadolinium calcium oxoborate, Ca4GdO(BO3)(3) (GdCOB), is an efficient nonlinear berate crystal presenting suitable sites for activator ions. Nd3+ doped GdCOB has been investigated as a new laser crystal in orde r to develop a self-frequency doubling material. Large and good optica l quality crystals of Nd:GdCOB have been grown from the melt. Nd3+ opt ical properties were studied via Judd-Ofelt analysis. Nd3+ polarized a bsorption and emission cross sections were measured at room temperatur e. Stark levels of Nd3+ 4Lj manifolds in GdCOB are given. Nd:GdCOB las er has been demonstrated, with a cw Ti:sapphire pump source, for sever al Nd3+ concentrations. The crystal was shown to lase along its three crystallophysic axes. The best slope efficiency is 45% for the fundame ntal laser output at 1.060 mu m. According to the infrared laser outpu t polarization, configuration of Nd:GdCOB crystals, for type I self-fr equency doubling in ZX and XY principal planes, were investigated. A 0 .530 mu m green laser was observed by self-frequency doubling. Linear and nonlinear optical properties of Nd:GdCOB are compared to those of NYAB in the prospect of self-frequency doubling applications. (C) 1997 Elsevier Science B.V.