Need help with this code Urgently!!!!!!!

I tried to modify a matlab code to achieve focusing in photonic crystal. i'm attaching the matlab code.
i used the data given by joannopoulos group. but i could not get the desired result.
can anyone please help me????? i would be highly obliged.

ps. if anyone have any working matlab code for the same kindly post it here

I assume you are trying to simulate a 2D photonic crystal slab as a superlens (in negative index frequency range ).
you have mentioned joanopoulos group data.what data? which paper? for some papers it was impossible (at least for me) to get the exact results mentioned. you should be more specific about your references.
another issue could be the resolution you are using for FDTD simulations
another one is the size of your structure, the number of columns and rows of your photonic crystal (PhC). the height of the PhC is a very important factor in FWHM and image distance.