an angled plane wave with bloch boundary



i simulated a case that plane structure illuminated with a plane wave at an angle with bloch boundary.
but the reflectance was wrong, could you help me to check it.
plane_bloch.fsp (1.2 MB)


The problem comes from the Bloch boundary condition: with a plane wave with non normal incidence, the angle varies with the wavelength (

To avoid that, you can either run a sweep of single wavelength simulations over the bandwidth of interest, or you can used the BFAST plane wave (

Note that BFAST can lead to some stability issues with dispersive material. I ran your simulation using this setting, but I had to set the BFAST dt multiplier to 0.1 to get stability.


thanks a lot