NONDEGENERATE 4-WAVE-MIXING MEASUREMENTS OF A RESONANTLY INDUCED REFRACTIVE-INDEX GRATING IN A ND-YAG AMPLIFIER

Two optical waves (at 1064 nm) were used to resonantly induce a popula tion grating in a flash-lamp-pumped Nd:YAG rod, and a nonresonant wave (at 1054 or 694 nm) was used to read (with a diffraction efficiency o f as much as 1% or 0.3%, respectively) the refractive-index grating ca used by the difference in the polarizability of the excited and the un excited Nd ions. Comparisons of experimental results and numerical cal culations gave the dependence of the ratio of the real and the imagina ry parts of the resonant susceptibility of Nd:YAG at 1064 nm on the pu mp power. (C) 1998 Optical Society of America.