Transmission of photonic crystal coupled-resonator waveguide (PhCCRW) structure enhanced via mode matching.

A method for increasing the coupling efficiency between ridge optical waveguides and PhCCRWs is described. This increase is achieved via W1 channel waveguide sections, formed within a two-dimensional triangular lattice photonic crystal using mode-matching. The mode-matching is achieved by low quality-factor modified cavities added to both the input and output ports of the PhCCRW. A three dimensional finite-difference time-domain method has been used to simulate light propagation through the modified PhCCRW. We have fabricated PhCCRWs working at 1.5microm in silicon-on-insulator material. Measurements and simulations show that the overall transmission is improved by a factor of two.