A NEW NONLINEAR AND NEODYMIUM LASER SELF-FREQUENCY DOUBLING CRYSTAL WITH CONGRUENT MELTING - CA4GDO(BO3)(3) (GDCOB)

A new compound, belonging to the M(4)RO(BO3)(3) (R = Gd, La, Y) oxobor ate family, was prepared as single crystals of large size by the Czoch ralski process. The non-linear optical properties of these biaxial cry stals are reported and appear to be comparable to those of BBO for sec ond harmonic generation. For the matrix Ca4GdO(BO3)(3), doped by Nd(3)ions, a laser emission at 1.06 mu m was demonstrated. Then, combinati on of frequency doubling and laser effect in the suitable conditions a llowed to generate, in an oriented crystal, the second harmonic of the fundamental IR laser beam: a visible green laser was obtained by self frequency doubling.