A Design Of Channel Add/Drop Filters Based On Photonic Crystals

Photonic crystals which have as the electric bandgap in semiconductors photonic bandgap are artificial structures in which the dielectric constant changes periodically. By introducing defects light can be efficiently controlled like the control of electronics in semiconductors. It is the distinct characteristics of photonic bandgap that have inspired great interests recent years and make people believe it is the semiconductors in optics. It seems that the time of controlling light by light is coming.Our purpose is a design of channel add/drop filters based on photonic crystals. First, the concept and characteristics of photonic crystals are introduced. Then from the Maxwell equations, two different methods solving problems involving photonic crystals are briefly introduced. The PWE method is used to analyze how structure parameters of photonic crystal affect the width of photonic band gap. And choose 2D square photonic crystal of special structure as the design platform. Then, different defect states and the coupling between them in this photonic crystal are investigated. Ultimately, a photonic crystal channel add/drop filter with symmetric 100% reflectors is proposed according to the results studied in the former chapters and state of arts.Theoretical analysis and numerical simulation both suggest that this particular photonic crystal channel add/drop filter has not only simple structure but also excellent performances.