二维光子晶体禁带的遗传优化算法，在平面波展开法的基础上，使用遗传算法寻找具有最大光子禁带的二维光子晶体结构-Two-dimensional photonic crystal band gap genetic algorithm, in the plane wave expansion method based on the use of genetic algorithms to find a maximum two-dimensional photonic band structure of photonic crystals