Two-dimensional photonic crystal for optical channel separation in azo polymers.

We have fabricated a two-dimensional photonic crystal that functions as a two-channel add/drop filter on azo-functionalized polymeric films using a fast, direct-writing method. By properly adjusting the resonance, this structure can be used as a multichannel add/drop filter in the plane of the film. Here, we were able to separate two channels at 1555.7 and 1570.7 nm with attenuation of 13.1 dB and FWHM of 6.7 nm for each channel. The separated channels were directed towards the sides at an approximately 90 degrees angle with respect to the input direction.