One-Dimensional Photonic Crystal Polarization Filter with Multiple Channels

Photonic crystal polarization filter is a new filter using the band gap property of photonic crystal to control the polarization state of the signal light. It has important applications in many areas, such as the optical fiber communication, optical sensing measurement, and optical information processing. The paper studies a one-dimensional photonic crystal polarization filter with multiple channels by the optical transfer matrix method. The study shows that defect layer thickness of photonic crystal (D) determines the number of filter channels (N), both similar to satisfy the linear relationship. The refractive index of defect layer has some influence on the number of channel variation, that is, the larger refractive index, the more channels. The location of central wavelength for filter channel can be adjusted by changing the number of unit layers and unit thickness of photonic crystals, which does not affect the number of filter channels.