Learning Forum

[higino.correia]

Hi,

I´m simulating a metalens and i would like to know how to calculate the optical power in the focal spot and divide it by the transmitted optical power of the lens.

I integrate the poyinting vector in the monitor at the nearfield to know the transmitted power of the lens, i use farfieldexact3d to extrapolate the farfield and get the E^2 across on the focal plane.
how do i get the poyinting vector at the focal plane.

Best regards,

João Borlido

 

[Guilin Sun]

You can simply integrate the focal sport pwer and the total transmitted power through the Poynting vector. When you use farfieldexact to get E fields at the focal plane, you can also get the H fields so you can calculate the Poynting vector. 

 

[higino.correia]

Hi,

Thank you very much for your answer.

Is it possible then to provide a script for calculating the poynting vector from E and H fields at the focal plane?

Best regards.

[Guilin Sun]

Sorry to reply you late. Somehow your reply is passed without notification.

First, you need to get H field from farfieldexact https://optics.ansys.com/hc/en-us/articles/360034930733-farfieldexact3d-Script-command by following the example. Once you have the field components, the integration is relatively easy. When it is in the xy plane:

Poyn=Ex*conj(Hy)-Ey*conj(Hx);

Pf=0.5*real(integrate(Poyn,[1:2],x,y);

integrate - Script command

You may need to pinch some singuletones: pinch - Script command 

Please try and let me know if you have questions in scripting.