Figure 1

Schematic diagram of the coupled heterostructure photonic crystal waveguide. a Cross-sectional view of the waveguide, depicting the photonic crystal arrangement within. The circles represent the spheres imbedded in each crystal, which are filled with air in photonic crystals A and B and a nonlinear dielectric material in photonic crystal C. The backbone material of each crystal consists of the same linear dielectric material. b Energy band structure of the waveguide in the direction of photon confinement. The dashed line located in the central photonic barrier illustrates how the position of the upper band edge of photonic crystal C shifts when the pump field is applied, where Δ ε denotes the change in energy. Note that the lower band edge of crystal C also shifts in a similar manner upon the application of the pump field; this is not depicted here, since we are only concerned with the PQWs formed by the upper band edges of photonic crystals A, B and C