Here, for convenience, the vector in 2D is represented by a complex number: the real part represents the x-component and the imaginary part represents the y-component. How to get the Fourier transform is the key of this program. Here I used the a

用平面波展开法计算的二维光子晶体空气孔结构，TM和TE模式的能带图，matlab程序源代码-With the plane wave expansion method to calculate the two-dimensional photonic crystal structure of air holes, TM and TE modes of the energy band diagram, matlab source code

this program calculates and plots the photonic bands for a 2D photonic crystal consisting of cylinders with circular cross-section and infinite height, arranged in a triangular lattice