Nondegenerate two-wave mixing in GdAIO(3):Cr(3+).
We have measured the nearly degenerate two-wave mixing in GdAlO(3):Cr(3+) crystals. In contrast to that in other chromium-doped materials, the signal in this sample arises from a mixed phase absorption grating where the absorption contribution is intensity dependent. The real (n(2)') and the imaginary (n(2)'') parts of the nonlinear index of refraction, the saturation intensity, and the excited-state lifetime are determined. The ratio r = n(2)''/n(2)' changes linearly with the intensity. Owing to saturation, the grating presents anharmonicities that give rise to self-diffracted beams (forward four-wave mixing). For comparison, results are also presented for ruby and alexandrite.
J C
JC
Penaforte
E A
EA
Gouveia
S C
SC
Zilio