Learning Forum

[GWANG]

Hi. FDTD Solutions uses a time domain solver. The simulation starts by inserting a short optical pulse into the simulation domain (through the source) and it runs (or should run) until the optical signal passes through the simulation domain completely. This means that your simulation time should be large enough so that the light from the source is able to cover the entire distance from the source to the end of the simulation region.

For example, if you have a simulation setup where the optical signal will travel for 5 micron before leaving the simulation region and the material has an index of 3.5 then the time required for the light to travel this distance is given by, t = 5e-6/c*3.5 sec = 58 fs. This means that a simulation time of at least 58 fs is required.