FDTD

First, Specify the global simulation parameters, such as the size, discretization characteristics, and boundary conditions. These parameters define the context of the device and the discretization can be used as a knob to balance accuracy with speed.

Next, Specify all of the geometries and material properties of the structures within the domain. Afterwards, define the excitation that injects electromagnetic energy into this system. This can be done by directly specifying a current source, such as a point dipole, or a desired field pattern, such as a plane wave, from which a current source distribution can be defined.

Finally, Define the quantities of interest to be measured from the simulation. For example, measuring the time dynamics of a field component at a point within the simulation domain or the flux through a plane. Defining these “monitors” up front means that less information will need to be stored and many of these quantities can be computed during the run, saving time.