Guilin Sun
Ansys Employee

There are two script files for this example: https://optics.ansys.com/hc/en-us/articles/360042097313-Metalens

Next time please specify which script file you are referring.

A1: I am not sure where we mentioned the mode amplitude. I think it is the E amplitude. E anfd H are the mode fields.

A2: m and n are the grating diffraction orders. They are result, not input parameters

Q3 " in RCWA, I am not sure how far for ekx_f... can we use the same method in FDTD to get this phase?"

and since this is analytical solution, the result is on the surface, similar to Fresnel coefficients.

Please visit this page https://optics.ansys.com/hc/en-us/articles/4414567929235-rcwa-Script-command

Amplitudes of E and H fields will be returned as ekx_f, eky_f, ekz_f, ekx_b, eky_b, and ekz_b

they are field amplitudes in k space for E and H.

Mode amplitudes will be returned as asx, asy, bsx, bsyapx, apy, bpx, and bpy

Here s and p are the polarization. a and b means E and H (I do not know why), and xy components only.

I do not know where "kx, ky" is from in which file?

index_sub = getfdtdindex("SiO2 (Glass) - Palik",excitation.f,min(excitation.f),max(excitation.f)); is to get the refractive index of the material (SiO2 in this case). 

 

pinch(pinch(Fields.E,5),5): please refer "pinch" https://optics.ansys.com/hc/en-us/articles/360034405674-pinch-Script-command

 

Please note that Fields.E is a 6 dimension matrix, x,y,z,f,radius and Ex/Ey/Ez in the 6th dimension.

 

dist = 0.151606*um; #Distance between source and first layer in FDTD model

should be from FDTD simulation file. But I believe the FDTD simulation file has been modified as this distance is no loner this value.

Earnestly, I really do not know why it uses those strange values. If I did this example, I would use some values to match the mesh, or some integer numbers.