Narrow transmission band of one-dimensional photonic crystals with a defect layer

Photonic crystals (PCs) containing defects have important applications in optical filtering with super narrow transmission band and photo phase adjustment. Resonance transmission bands in one-dimensional PCs with a defect mode are calculated by the transfer matrix method. The effect of two primitive dielectric refractive index ratios and position of the defect in PCs on filter quality are analyzed. The photonic band gap of PCs, the narrow resonance transmission band made by defect, and the relationship between refractive index of defect layer and the peak value of narrow resonance transmission band are discussed. The physical mechanisms can be explained by the photonic potential well and potential barrier scattering for photons.