Fig. 1. Computation results of photonic structures PCI and PCII with inversion symmetry and their composite structure in first two band gaps. (a) One-dimensional composite photonic structure consisting of A and B materials; (b) reflectance spectrum and imaginary part of impedance of PCI; (c) reflectance spectrum and imaginary part of impedance of PCII; (d) reflectance spectrum and imaginary part of impedance of composite structure

Fig. 2. Conditions for composite structure PCI+PCII producing interface states. (a) Reflectance of composite structure versus sum of imaginary parts of impedances of PCI and PCII; (b) reflectance and imaginary part of impedance of composite structure at interface state

Fig. 3. Composite structures composed of PCI and PCII in alternate arrangement. (a) Diagram of composite structure PCI+PCII+PCI; (b) reflectance and imaginary part of impedance of PCI+PCII+PCI; (c) diagram of composite structure PCI+PCII+PCI+PCII; (d) reflectance and imaginary part of impedance of PCI+PCII+PCI+PCII

Fig. 4. Electric fields of light at interface state in one-dimensional composite structures (q=0 corresponds to left input end face of composite structure, and q=120 corresponds to right output end face of composite structure ). (a) Electric field distribution of interface state (1/λ₁=1.71452 μm^-1) in PCI+PCII structure; (b)(c) electric field distributions of interface states in PCI+PCII+PCI structure (1/λ₂=1.71196 μm^-1 and 1/λ

Fig. 5. Regulation of interface states in composite structure of PCI+PCII+PCI. Unit cell number of PCI is N=30 and unit cell number of PCII is M. (a) M=30; (b) M=40; (c) M=50; (d) M=58; (e) M=60; (f) M=62