Generation of quadratic spatial dark soliton in periodically poled lithium niobate

In this paper, we report the evolution of quadratic spatial dark soliton in periodically poled lithium niobate (PPLN). The generation of solitons pairs by wavefront modulation methods is investigated in both numerical simulations and experiments. We found that quadratic dark spatial solitons have analogue performances compared with that in χ(3) defocusing Kerr media.