Fast guided mode of a photonic crystal waveguide

A fast guided mode of a photonic crystal (PC) waveguide was investigated. Dispersion curve of the PC waveguide was calculated and compared to that of a volume-equivalent Si rectangular waveguide. At a wavelength of 1550 nm, the dominant phase velocity and the group velocity of the PC waveguide were higher by 4.6% and 3.4%, respectively. The PC waveguide was incorporated into a Mach-Zehnder interferometer for measuring the guided mode. Normalized measured intensity versus PC waveguide length was found to obey the predicted interference intensity curve which suggested guiding of the mode. Loss associated with the PC waveguide was estimated from the curve to be about -5.6 dB.