Second-harmonic green generation from two-dimensional χ(2) nonlinear photonic crystal with orthorhombic lattice structure

The characteristics of nonlinear photonic crystals (NPC) with an orthorhombic lattice structure were discussed. The far-field emission pattern of second-harmonic generation (SHG) was monitored to study the quasiphase-matching (QPM) mechanism of nonlinear wave interaction. Second-harmonic generation was resulted from the pumping of NPC by a neodymium laser beam. The significance of a series distribution of green SHG in a direction transverse to the fundamental beam was also explained.