Galisteo-López J F, Galli M, Balestreri A, Patrini M, Andreani L C, López C
Opt Express. 2007 Nov 12;15(23):15342-50. doi: 10.1364/oe.15.015342.
Phase measurements on self-assembled three-dimensional photonic crystals show that the group velocity of light can flip from small positive (slow) to negative (superluminal) values in samples of a few mum size. This phenomenon takes place in a narrow spectral range around the second-order stop band and follows from coupling to weakly dispersive photonic bands associated with multiple Bragg diffraction. The observations are well accounted for by theoretical calculations of the phase delay and of photonic states in the finite-sized systems.
对自组装三维光子晶体进行的相位测量表明，在几微米大小的样品中，光的群速度可以从较小的正值（慢光）转变为负值（超光速）。这种现象发生在围绕二阶禁带的狭窄光谱范围内，是由与多重布拉格衍射相关的弱色散光子带耦合引起的。有限尺寸系统中相位延迟和光子态的理论计算很好地解释了这些观测结果。
