为了了解电磁波在光子晶体中的传输特性，用MATLAB与时域有限差分法把电磁波在真空与光子晶体中的传播实时可视化，并给出了场的空间静态分布。数值模拟的结果表明，禁带中的波被光子晶体控制，其能量分布在介质柱中，并观察到了电磁波局域化现象。

In order to see the transmission of electromagnetic wave in photonic crystals,the finite difference time domain method was used to calculate the band gap of two-dimension photonic crystals,and with the help of MATLAB,it could make the transmission of the electromagnetic wave in the vacuum and photonic crystals visual. At the meantime,the static map was shown. Numerical analysis showed that the wave in the forbidden band was controlled in photonic crystals,and its energy distributed in the media rod nearby,the localization of electromagnetic was observed.