Tunable Wavelength Filter Based on Complex Period Photonic Crystal

A new-style tunable photonic crystal filter was proposed, its structure is the liquid crystal defect films are introduced to the one-dimensional photonic crystal periodically composed by three different refractive index mediums. The spectrum transmission was obtained by using the transfer matrix method and liquid crystal Jones' matrix, we synthetically analyze the properties of the complex period photonic crystal infiltrated with nematic liquid crystal and the influence of many factors such as liquid crystal thickness, photonic crystal periodicity and adjacent medium thickness increment. The filter has different job windows in 1550 nm、1330nm etc, by changing the thickness increment of the adjacent medium behind the liquid crystal, and the tuning range of which has 30nm and above .