Learning Forum

[Saravanapriya]

Hello support

My plot.jpg

[Guilin Sun]

The figure caption shows "Nanopost Width" and "nanopost Length" and it seems you did the the same. I am not if you have corrected the propagation phases from source to the device interfaces, and then to the monitors. Please refer this: Metamaterial S parameter extraction The phase you want to quantify should only be resulted from the device its self, I believe. Please check if you have used the correct analysis group and the propagation phases have been removed.
Duplicating other's result can be very challenge. The paper may not give all the device properties, eg the actual material data they used. Maybe they just say a material name but a material can have quite different data depending on the process and measure (and the providers). For example Lumerical FDTD has 3 sets of silver refractive index and we cannot say one is wrong, as all of them are measured and published. There are many other aspects that need to take care of. Please refer this post: Ansys Insight: Why my simulation result is different from published paper or experiment?

[Saravanapriya]

How to make sure or check if the propagation phases are corrected?

[Guilin Sun]

As you may know, there are two steps in designing a metalens: element design to get the relationship between phase created and the geometry/orientation/period, which uses periodic BCs, and metalens simulation with specially arranged elements, by matching the desired phase at each location. Once your first step is done, usually the second step is for verification. The result will not only depend on the 1st step but also depend on the arrangement of the elements.
So when you say to check the correct propagation, I guess you want to make sure the metalens performs as desired. This can be done by simulating the whole device, provided that the element design and the relationship is correct. Please try and see what problems you may have.
You may also need to read more details from the online example.