High Transmission and Low Group Velocity of a Photonic Crystal Coupled-Cavity Waveguide

A two-dimensional photonic crystal coupled-cavity waveguide was designed and optimized by combining photonic crystal wavguide and cavity,transmission spectra of the waveguide were calculated by using FDTD method,and the transmittance and the group velocity were obtained through the transmission spectra.The calculation results show that a group velocity of vg=c/130 and corresponding transmission of 20.1% can be obtained at wavelength 1.551 μm,and a group velocity of vg=c/50 and transmission of 29.2% was obtained at wavelength 1.502 μm.The slow light in the waveguide was also analyzed by using photonic bandstructure calculated by plane-wave-expansion(PWE) method.The results of the photonic crystal waveguide with high transmission and low group velocity will have potential application in optical storage,optical delay and photonic integration.