Study on the second-harmonic-generation of GdCa4O(BO3)3 crystals along various phase-matching directions

In this paper, the theoretical calculations of d(eff) of GdCa4O(BO3)(3) (GdCOB) along various phase-matching (PM) directions are reported. It is shown that the maximum d(eff) is out of the main planes and the d(eff) in the range of (0 < theta < 90, 90 < phi less than or equal to 180) are larger than that in the range of (0 < theta less than or equal to 90, 0 less than or equal to phi less than or equal to 90). The PM direction along (theta = 66.8, phi = 132.6) for GdCOB crystal has the largest d(eff). Second-harmonic-generation (SHG) experiments were performed on GdCOB crystal along various PM directions. The results show that in GdCOB crystal, the intracavity SHG conversion efficiency is 27.6% along the PM direction (theta = 66.8, phi = 132.6) which is larger than that along PM directions in XY and XZ main planes, which are in good agreement with the theoretical calculations. The continuous-wave (cw) green laser output power is 1.22 W when LD pump power is 10 W in the Nd:YVO3/GdCOB laser. (C) 2000 Elsevier Science Ltd. All rights reserved.