Enhanced SHG power using periodic poling of and vinylidene cyanide/vinyl acetate copolymer

Embedding poling-inverted corrugation of the optical nonlinear susceptibility into vinylidene cyanide/vinyl acetate organic copolymer, the second-harmonic (SH) power has been enhanced at pulsed Nd:YAG 1.06 μm and Er:YAG 2.94 μm laser lines by quasi-phase matching (QPM) the interaction between the fundamental and SH waves. Using a sample with a corrugation period of 120 μm with poling corrugated by an interdigital electrode, an enhancement factor of about 94 and ~3 was obtained at 1.06 μm and 2.94 μm, respectively, in comparison with a bulk sample having uniform poling. Taking the first-order QPM, the maximum conversion efficiency was also about 0.001 percent at the wavelength λ_ω=1.06 μm, with the fundamental peak power P_ω of 2.5 W, and the extinction coefficients of α_ω=α_2ω=0.7 mm^-1 in the film having a path length of 2.4 mm, while ~0.03 percent at λ_ω=2.94 μm with P_ω=200 W, and α_ω=1.4 mm^-1 and α_2ω=0.7 mm^-1 for the same film