Novel Optical Demultiplexer Design Using Oblique Boundary in Hetero Photonic Crystals

In this letter, we report a novel approach in demultiplexer design by performing wavelength separation in hetero photonic crystal (HPC) with an oblique boundary. First step, demultiplexing action is considered like ordinary demultiplexers using wavelength dispersion in photonic crystals. Contrary to ordinary demultiplexers, the oblique boundary in HPC causes components of Bloch wave-vectors of different wavelengths not to be equal in the second step. This change in Bloch wave-vector results in ultra-high separation angles for incident wavelengths. A beam divergence of 133 degrees is obtained for an input range from lambda(1) = 1521 to lambda(4) = 1550 nm.