Group velocity dependence of propagation losses in single-line-defect photonic crystal waveguides on GaAs membranes

Group velocity, vg, dependence of propagation loss in single-line-defect photonic crystal waveguides on GaAs membranes, and minimum loss as low as 2.5 dB/mm, are presented. When vg is reduced by a factor of 7, an additional loss is found to be only 5 dB/mm, thus proving a feasible usage of low vg.