Wavelength Demultiplexer Based on a Two-Dimensional Graded Photonic Crystal

Flexible implementation of graded two-dimensional planar photonic crystals is proposed for wavelength demultiplexing. Equations of Hamiltonian optics are used to study light propagation beyond the homogeneous regime using an analytical approximation of the graded photonic crystal dispersion relationship. The approach is applied to a graded structure enabling two-wavelength demultiplexing for three possible sets of wavelengths around λ = 1550 nm. Insertion loss and interchannel crosstalk calculated using finite-difference time-domain simulation are -1 and -20 dB, respectively.