Learning Forum

[Odebowale]

I am trying to obtain complex reflection (r) and transmission (t) coefficients for both s and p polarization at normal incident for a metasurface design consisting of Au/Al2O3/Au. I understand from theory that R and T are equal for both s and p polarisations at normal incident . My questions are: 1) Is S-parameters for s and p polarization at normal incident the same? 2) If no, how can I adjust my simulation setting for s and p polarization so as to extract the accurate values for the S parameters (S11 and S21 or S22 and S12). Thanks while I await your response.

[Guilin Sun]

The theory has assumption that the structure is symmetric. Is your structure symmetric for s and p polarization? say it is circular shape?

Please refer to this example: https://optics.ansys.com/hc/en-us/articles/360042097393-Metamaterial-parameter-extraction-Smith

[Odebowale]

The link you provided is what I used for the extraction of the S parameters in my design. For the question you asked "Is your structure symmetric for s and p polarization?" I don't know how to determine if it's symmetric for both polarizations. Below is the picture of the structure. Thanks for your response

[Guilin Sun]

This structure is not symmetric in any sense, thus s and p results will not be the same. In the textbooks it is the planar, thin film type, which has symmetry so the results are the same.

[Odebowale]

 

Thanks for your response. I really appreciate.

How can I obtain S parameters for my structure for both s and p polarizations?
Do I need to change polarization angle to 90 degree for p and 0 degree for s based on this convension?

source of Fig1: https://optics.ansys.com/hc/en-us/articles/360042095873-Metamaterial-S-parameter-extraction