Logical gates on trapped modes in photonic crystals with nonlinear coating

摘要

We propose two principal schemes of all-optical adders and logical gates based on the dependence of electromagnetic spectra in photonic bandgap materials containing optically nonlinear layers on the light signal intensity. The photonic structure behavior with changing intensity is investigated for system consisting of periodical layered structure covered with optically nonlinear material. The theory of photonic band and local states dynamics is developed for linear 1D and 2D Si-SiO_2 and Ge-Se photonic crystals coated with the nonlinear doped glass. It is shown that the beam angular-frequency diagrams contain extremely sensitive areas inside the total reflection range, where the weak nonlinearity leads to dramatic change in light reflection and transmission. An overview of suitable nonlinear materials and PBG structures is made to evaluate logical device parameters for different frequencies of laser sources.