Slow light in photonic crystal with combinations of gradient dielectric constant

A line defect waveguide formed by a new kind of two-dimensional photonic crystal with combinations of gradient varied dielectric was designed and the properties of slow light will been studied by using the Plane Wave expansion Method (PWM). The result shows that the group velocity is slower when the corresponding combination of gradient dielectric constants are with higher dielectric constant and lower interval. In our new structure of photonic crystal, the corresponding group velocity can reach as low as 0.06c (c: light velocity in vacuum), two orders magnitude lower than light velocity. Meanwhile, the group velocity dispersion effect is relatively small.