Polarization-independent Low-pass Spatial Filters Basedon One-dimensional Photonic Crystals Containing Negative-indexmaterials

摘要

A new application of one-dimensional photonic crystals containing negative-index materials is proposed as low-pass spatial filters. Through optimizing the parameters of defect layer, a series of polarization-independent defect modes in the zero-average-index gap of the photonic crystals are obtained with the increase of the incident angle. Based on these defect modes, polarization-independent low-pass spatial filters are designed. The spatial-frequency bandwidth of the spatial filters can be adjusted by changing the period number of the defective photonic crystal structures. In addition, the effect of the losses of negative-index materials on the spatial filters is considered.