Highly efficient channel drop filter based on photonic crystal oneway waveguide

We design a highly efficient channel drop filter (CDF) with only one channel drop micro-cavity based on photonic crystal (PC) one-way waveguide. By means of the new nature of waveguide-cavity interaction, over 95% channel drop efficiency can be realized in the structure. Some multichannel drop filters with high drop efficiencies are also engineered based on such the structure. These numerical results are all calculated by using the finite element method (FEM), which agrees well with the theoretical analysis result.