Second-harmonic generation was z-cut observed Gd1 - xYxCa4O(BO3)(3) (Gd1 -
xYxCOB) and the dependence of the phase-matching wavelength on the mixing r
atio x has been investigated. The dependence on both temperature and angle
tuning was examined as well. We found the suitable composition for noncriti
cal frequency doubling at 930 nm, which is the lasing wavelength of Nd:YAlO
3 on the F-4(3/2) --> I-4(9/2) transition.