In order to obtain the photonic band structure you need to employ periodic boundary conditions. You store the field at the detecting point, previously stablished, during the calculation, and at the end you need employ, for example, a fast fourier transform to obtain E(w) for each k value. I suggest the book:

http://www.springer.com/gp/book/9783642026454

At the end of the chapter 8 they show an algorithm in matlab, which is very easy to implement in C language.

Dear Ricardo

Thank you for your answer. I watch it.

Now I read FDTD book by Sullivan.Is it suitable for calculating band structure and understanding the related codes?

Best

Hamed

I think Sullivan's book is an excellent introduction to the FDTD calculations (maybe the best), but unfortunately doesn't have an introduction to the periodic boundary conditions, then you can't use it to learn how to calculate the PBS. By using below link, you can find, for free, another excellent introductory book (but without periodic boundary conditions)

http://www.eecs.wsu.edu/~schneidj/ufdtd/ufdtd.pdf

To determine band structure of photonic crystal I prefer PWE (plane wave expansion) method. Because of at FDTD you will need make Fourier analysis  to obtain w(k)  (w is omega). FDTD is not good suitable for band structure analysis because of need large computational resources. 

If you photonic crystal does not contain nonlinear materials or  materials with dispersion n(w) not constant, I recommend you to use PWE. 

Dear friends

Thank you for your guides. But dispersion curve is important for my project:designing waveguide. So as Ricardo said FDTD is necessary for dispersion.

I think the book by Igor A.Sukhoivanov

Igor V.Guryev (Photonic Crystal) is proper for FDTD method for PBC.

Best

Hamed,

you can calculate the chromatic dispersion of your waveguide using PWE. Check this reference for example:

http://dx.doi.org/10.1364/OL.30.000453

There the authors show how to calculate the second derivative of \beta using PWE. Also I recommend you the open-source software MPB:

http://ab-initio.mit.edu/wiki/index.php/MIT_Photonic_Bands

have fun!

Dear Felipe

Thank you very much.

Best

Hamed