Channel drop filter with fast-slow light conversion based on photonic crystals

In the paper, a channel drop filter (CDF) with fast-slow light conversion is proposed based on two-dimensional (2D) photonic crystals (PCs). In the structure, the bus waveguide is designed with a large group velocity as a fast light waveguide, while the dispersion relation of channel drop waveguide is tailored by adjusting several waveguide structural parameters to get a little group velocity in such slow light waveguide. It is confirmed that the fast light signal in the bus waveguide is transferred to the channel drop waveguide with the conversion to the slow light signal, where the channel drop efficiency is close to 100%. The device in PCs compound of the functions of CDF and fast-slow light conversion, and would be very useful in next generation optical network node.