High-efficiency surface-emitting channel drop filters in two-dimensional photonic crystal slabs

We analyze theoretically the output efficiencies of surface-emitting channel drop filters using channel drop tunneling processes in two-dimensional photonic crystal slabs. By using the channel drop tunneling processes, the output efficiencies of the filters can be easily improved to the values much higher than 50%, the maximum output efficiency of surface-emitting channel drop filters using one single-mode cavity, and the output efficiency of 100% is possible theoretically. In order to demonstrate the theoretical results, we present a surface emitting channel drop filter using the channel drop tunneling processes in a two-dimensional photonic crystal slab. The output efficiency of the presented filter is about 94% in good agreement with the theoretical analysis.