Learning Forum

[uzmayaqoob1960]

Dear all 

can any one plz guide me how to reconstruct stokes parameters if we are privided with simulation results like for 45-polarized light we are getting such image .low intensity spot in upper row are for RCP and LCp ,diminished spot is for -135 degree polarized light and lower two spots are for x and y polarized light respectively.Can any one plz guide the reconstruction procedure?

[Guilin Sun]

FDTD results are Ex,Ey and Ez (and H if needed). You should be able to get the Stokes parameters from them. You may find your own reference but I found this SPIE paper: https://spie.org/publications/spie-publication-resources/optipedia-free-optics-information/fg05_p12-14_stokes_polarization_parameters#_=_

However I do not know how did you get the fields distribution with different polarization states. You may quantify each of them, or quantify them as one beam, based on your results and need. 

 

[uzmayaqoob1960]

Dear sir if i want to extract the intensity of x component let say then would i just take square of Ex component or there is some way to extract intensities directly from monitor?

[Guilin Sun]

You can use script like this:

for only Ex, Ex=pinch(getdata("monitor","Ex"));

"pinch" is to remove singletons.

You can also use

E=getresult("monitor","E");

Ex=pinch(E.Ex)

then use abs(Ex)^2 to get the intensity of Ex.

But usually we need total intensity. 

[uzmayaqoob1960]

 

Sir when i run script i dont get a numeric value rather dimensions like shown below how to get numeric value for intensity?like sir in Fig 2 we are getting source intensity in Fig 2.In Figure 2 we are able to get area of monitor as well can we get area of any monitor as i tried but except source monitor couldn't get arae of other monitors.

 

[Guilin Sun]

Your first script gave you correct numerical result.

The area is calculated by Yee cell. It may differ from theory because of discretization:

In discrete world, the area may not be decribed as in continuous world. If you want to get accurate area, you can use x_span*y_span where

x_span=getdata("monitor","x span")

y_span=getdata("monitor","y span")

[uzmayaqoob1960]

thank u sir and how to get intensity of a monitorin numeric value like for source intensity we have command "source intensity" but for any other monitor how could we get that ?As whwn i run the script i got dimebsions as shown above I[277,333] not a single answer

[Guilin Sun]

E2=getelectric("monitor");

or

E2=E.E2;

Or 

E2=abs(Ex)^2+abs(Ey)^2+abs(Ez)^2;

as long as you get E dataset using getresult("monitor","E");

Please note that, your monitor is a 2D monitor, so its data is spaially distributed. If you are sure it is a plane wave, you can use any point 's E to reprent the plane wave. Otherwise you will need 2D data in physics.