Growth and investigation of efficient self-frequency-doubling NdxGd1-xCa4O(BO3)3 crystal

In GdCa4O(BO3)(3) (GdCOB) crystal, the Gd3+ ions can be substituted by Nd3+ ions within the concentration of 0-100 at%. Combined laser action of the Nd3+ ions and nonlinear optical (NLO) properties of GdCOB crystal host in the mixed NdxGd1-xCOB causes the crystal to become self-frequency-doubling (SFD) material. The synthesis and crystal growth of NdxGd1-xCOB are reported in this paper. The polarized transmittance spectra and fluorescence spectra were measured at room temperature. The strong emission peaks in the range of 850-950 nm are reported for the first time for the NdxGd1-xCOB crystal. The (theta = 66.8 degrees, phi = 132.6 degrees) phase-matching direction was reported for the first time as the optimum phase-matching direction at 1060 nm by calculation and experiments whose d(eff) was measured and found to be 2.1 pm/v. The SFD experiments were carried out on 3 x 3 x 7 mm(3) sample with (66.8 degrees, 132.6 degrees) direction. The green output power at 530.5 nm was 192 mW when pumped by 1600 mW Ti : sapphire tuned to 811 nm. The threshold was 16 mW. The optical-optical conversion efficiency was 12%. (C) 1999 Elsevier Science B.V. All rights reserved.