Learning Forum

[Cameron Nelson]

Hello,

I'm wondering if you can verify the incidence angle directions for plane wave sources in FDTD and RCWA. 

In both cases, I am running simulation with a backward propagating plane wave source incident on a diffraction grating strcutre. I am measuring the first order diffraction efficiency. For FDTD, the GUI shows that a negative incidence angle represents a rotation of the plane wave in the counter-clockwise direction. The FDTD and RCWA data is consistent, however it appears as though the sign of the incidence angle is switched. In other words, to make the RCWA AOI-dependent data consistent with FDTD, I have to multiply every incidence angle by -1. Is this discrepancy known?

[Guilin Sun]

This post will be closed as its questions have been answered in another post /forum/forums/topic/sign-convention-of-diffraction-order-numbers-of-lumerical-fdtd-rcwa/#post-349219.