Photonic Crystal Coupled Cavities With Four Ports Channel Drop Filter Based On One-Way Waveguide

We design a highly efficient channel drop filter (CDF) and sensor with two channel drop micro-cavities based on photonic crystal (PC) one-way waveguide. According to the coupled mode theory in time, the conditions to achieve 100% drop efficiency are derived thoroughly. The numerical results are all calculated by using the finite element method, and accord well with the theoretical analysis. Compared with previous one cavity based on general dielectric PC, the CDF based on PC one-way waveguide first shows almost complete channel drop tunneling at resonance. Since the coupling cavities system can extremely enhance the drop depth, which can significantly suppress crosstalk among bio-detectors, we can use this system to build tandem multi-detector application.