We rigorously analyze the dispersion function and the curvature of the dispersion surface of a photonic crystal to explore the fundamental limit of its angular sensitivities. With insight gained from group theory, we fi nd that symmetry indu

用matlab写的一个模仿抛物线动作的动画。可以自己设定加速度、启示位置等数值。-The laws for rotation are probably wrong (I made them up actually), but that s not what this file is about. Shown here is a very simple code that creates a nice animation, which can be quickly edited to suit a