Multi-layer stacks can have complicated reflection and transmission patterns. In the case of unpatterned slabs, there are simple analytic formulas for R and T as a function of angle for each polarization. These example show how to measure the reflection and transmission of a multilayer stack with an FDTD simulation.
In many cases, a 1D stack simulation is used an an initial starting point to verify the accuracy of the FDTD solution, since an analytic solution exists.
Two approaches are available for studying 1D systems: Use the analytic 1D stack RT script function or use a direct FDTD simulation.
The stackrt script function uses an analytic transfer matrix approach to calculate the complex reflection and transmission coefficients of a 1D stack.
For more information, see the Transfer matrix RT calulator page.
When the stackrt script function described above is not sufficient, an FDTD simulation can be used to study a 1D stack. See the following pages for examples and more information.