ABSTRACT
In this paper, the second harmonic generation in one-dimensional multi-layer LiTaO3 structure has been studied. To study and review the conversion efficiency, fundamental and second harmonic wave propagation inside the designed structures in this paper, we use the transfer matrix method. In the structures investigated due to the existence of the gap, density of passing electromagnetic modes in the edge of the gap and the defect modes is large. Also, the electromagnetic wave velocity is small. These factors produce a strong nonlinear optical interaction.