Spectroscopic properties, self-frequency doubling, and self-sum frequency mixing in GdAl3(BO3)4:Nd3+

We present the absorption and emission spectroscopy of GdAl3(BO3)(4):Nd3+ as functions of the sigma and pi polarizations. From the Judd-Ofelt analysis extended to anisotropic crystals, we have determined the parameters Omega (2 sigma) = 1.455 x 10(-20) cm(2), Omega (4 sigma) = 1.175 x 10(-20) cm(2), Omega (6 sigma) = 2.043 x 10(-20) cm(2), Omega (2 pi) = 0.208 x 10(-20) cm(2), Omega (4 pi) = 0.326 x 10(-20) cm(2), and Omega (6 pi) = 1.257 x 10(-20) cm(2). The radiative lifetime of the 4 F-3/2 level is 293 mus. The a-polarized stimulated emission cross section was measured to be 3.0 x 10(-19) cm(2) at the laser wavelength of 1061.9 run. No excited-state absorption was found at this wavelength. Green generation by self-frequency doubling was obtained with a yield of 4.3%. Blue generation tuneable in the 436-nm to 443-nm range was obtained with a yield of 7.3% from self-sum frequency mixing. (C) 2001 Optical Society of America.