One-Dimensional Photonic Crystal-Based Multichannel Filters Using Binary Phase-Only Sampling Approach
For one-dimensional (1-D) photonic crystals, the amplitude reversal in refractive index profile is defined as an equivalent pi phase shift. With these defined pi phase shifts, the binary phase-only sampling approach can be implemented to design 1-D photonic crystal-based multichannel filters. Such filters exhibit high-count channels and excellent channel uniformity, which is identical with the phenomena obtained in sampled fiber Bragg gratings (SFBGs). Simulations of a nine-channel filter are given out and the distribution of reflection peaks is consistent with that of SFBGs. Then, the impact of structural parameters on filtering characteristics (especially the peak-trough contrast ratio) is discussed, such as optical length of unit cell, optical thickness ratio of alternate dielectric layers, and apodization technique.