Photonic Green´s functions calculation by using FDTD method

The procedure of calculation of photonic Green´s functions by using the finite-difference time-domain method is presented. The main steps of this procedure are considered and basic expressions are derived. By using these expressions the discrete forms of Green´s functions can be derived and applied to solve the problems of electromagnetic wave scattering and propagation in periodical structures like photonic crystals. The discrete Green´s functions can be also used to act as absorbing and dispersive boundary conditions. All these features are shown by the example of electromagnetic field propagation in the two-dimensional photonic crystal with defects.