Optimization of an Ultracompact Triplexer Using Planar Photonic Crystal Waveguide

An ultracompact triplexer based on a shift of the cutoff frequency of the fundamental mode in a planar photonic crystal waveguide with a triangular lattice of air holes is presented and optimized. Some defect holes are introduced to control the beam propagation. The radii of the holes are changed to realize it. The numerical results obtained by the finite-difference time-domain method show that the proposed triplexer with a total size 12 mu m x 6.5 mu m can separate three specific wavelengths i.e. 1310, 1490 and 1550 nm with the extinction ratios higher than -18 dB.