This is a short post just for sharing an example of setting up for resonant waveguide grating with Zemax RCWA.

We will use the data in this paper: https://onlinelibrary.wiley.com/doi/10.1002/lpor.201800017

In attached file, a grating is set up, following the paper, as shown below. The grating parameters are as below.

Period = 0.4 µm

Duty cycle = 0.5

index of substrate = 1.6

index of superstrate = 1.0

index of the grating  = 1.7

thickness of lower part = 0.3 µm

thickness of upper part (binary grating) = 0.05 µm

We then intput a ray with TE polarization and 15 degrees incident angle with wavelength scanning between 0.546 µm ~ 0.552 µm.

By observing the 0 order reflection ray, the result is as below. This matches to the Figure 8 in the paper.

People can change the thickness of upper part of the grating to 0.025 µm and 0.1 µm to also check the result in the Figure 8 in the paper.

Have fun!