Second harmonic generation in photonic-crystal one-dimensional media

SHG is analysed in photonic crystals of two types (crystals consisting of quarter-wavelength GaAs layers alternating with silica layers and AlAs/GaAs crystals) depending on the number of structure periods and the pump intensity. Calculations show that in photonic crystals with the difference in the refractive indices Δn = 0.585, SHG occurs only in the reflected light and in two directions for a periodic structure with Δn = 2.