Learning Forum

[Jeongsoo Kim]

Hello,

I am trying to simulate the scattered field after illuminating the sample at various illumination angles.

When I look at the results using the Monitor, the electric field is calculated as a vector with Ex, Ey, and Ez. Is there a way to convert this field to scalar form? I think the magnitude of the field can be obtained through the square sum of the three-way field values, but I don't know how to find the scalar form phase value.

 

[Amrita Pati]

Hi Jeongsoo,

I am not sure what you mean by the scalar phase form. If you expect a single phase function among Ex, Ey, and Ez, you can just use the phase of the dominant field component.

Regards,
Amrita

[Jeongsoo Kim]

Hello Amrita

 

I want to propagate results using scalar diffraction theory and in the scalar diffraction theoey, one assume field of all the directions are same and use only one direction vector information. However, the Lumerical simulation results come out in vector form with different each other, so I would like to convert them to scalar form. I can calculate the magnitude of the entire field, but I don't know how to calculate the phase. As in the answer, if you use the phase of a field in the dominant direction, there is an illumination angle that produces similar values ​​in all x, y, and z directions, making it difficult to use. Is there any other method or formula information that might be helpful in converting the results?

[Guilin Sun]

This is a more theoretical question: scalar vs vectorial.

FDTD solves the Maxwell Equations with full vectorial fields, whereas the scalar one is approximate. In case the field components have similar values, you may try to use magnetic fields. or possibly transfer the Cartisian results into spherical coordinates if the later gives a better representation. Or better to use the farfield result to quantify the phase, where it has only two components, Ep and Es. If they are on the same order, then choice is yours. As long as the result can explain the physics, it wshould work.