Overview of the laser and non-linear optical properties of calcium-gadolinium-oxo-borate Ca4GdO(BO3)(3)

Ca4GdO(BO3)(3) (GdCOB) is a new non-linear optical (NLO) material which pre sents a congruent melting and can be grown from the melt in large size crys tals (phi=50 mm, L=120 mm) using the Czochralski pulling method. This paper describes the crystal growth and NLO properties of GdCOB which compare fav orably with those of commercial berates like BBO or LBO. Particular emphasi s will be put on SHG of the Nd:YAG 1.064 mu m laser emission. Large amounts of Nd or Yb ions can be substituted for Gd in this material and Ln:GdCOB w ith Ln=Nd, Yb exhibits interesting laser properties, especially in the case of diode pumped Yb activated crystals. Finally by combining the NLO proper ties of the GdCOB matrix and the laser emission associated with the active ion, a green self frequency-doubling laser is obtained. In this field, Nd:G dCOB appears the most promising material for practical applications, able t o generate visible green laser light with only one single crystal instead o f two, as usually. To date an Nd:GdCOB crystal yields 114 mW at 530.5 nm (f or 1250 mW of absorbed pump power), when pumped with a 2 TY high brightness laser diode. (C) 2000 Published by Elsevier Science S.A. All rights reserv ed.