Bandgap separation and optical switching in nonlinear chiral photonic crystal with layered structure

The chiral photonic crystal (PC) with layered structure is investigated by using the finite-difference time-domain method. The bandgap separation for right-hand/left-hand circularly polarized light in chiral PC is demonstrated by comparing to the achiral case. The effect of layer number and the optical nonlinearity on bandgap structure is analyzed. Optical switching with the help of the change in bandgap structure is discussed. A novel scheme of an all-optical switch based on sideband improved by apodization is proposed