The procedure is to illuminate your particle with a TFSF source.

Inside the TFSF box, you'll need to surround the particle with a power sensor, that will give you the absorption cross-section avec proper normalization.

Then you'll need to surround the TFSF box itself with another power sensor to extract the scattering cross section.

If that's already what you're doing, describe where things go wrong.

Dear Loïc O. Le Cunff,

Thanks for giving the response. I am a little bit confused about the term "Power Sensor", which you have used in the comment.

I am new in this era, so I did not understand the term power sensor. I think it will be a power source instead of a Power Sensor.

I power up the particle by following the attached image.

it will be your greatness if you are a little bit elaborate on the term power sensor.

I am waiting for your kind guidance

Sensor as in "what extracts data from your simulation", I answered the question generally. In the specific case of Lumerical, they're called "monitors" I believe.

In any case, your setup looks correct. What is the actual issue when you say you're not getting the results you're expecting?

Have you tried with a simple spherical particle compared to the Mie theory?

Respected Sir!

I didn't try with simple spherical particles compared to the Mie theory

it is requested please tell me I don't know how to try this one.

Can you tell me what is the distance between the source and monitor if it matters?

Mie theory derives analytical solution to the scattering of spherical particles.

As such, if you were to compute the cross sections of a simple gold sphere through FDTD for instance, you'd be able to compare them to the theoretical results.

If you want to know the theory, have a look at Bohren and Huffman's Absorption and Scattering of Light by Small Particles.

Try MiePlot, it's an advanced software as far as Mie's theory goes: http://www.philiplaven.com/mieplot.htm

As long as a few FDTD cells (let's say 10 to be sure) exist between the monitors and the source is should be fine. Issues should really only arise if any of them coincide.

Hello Sir

first of all, I am very thankful to you for all this discussion

Sir, I am sending you the paper which I want to reproduce.

I need your further kindness, am I doing wrong or right?

Please find the attached paper

I want to reproduce figure 1,2,3

Using you.com

To calculate the scattering and absorption of nanoparticles in Lumerical code 12, you can use the Finite Difference Time Domain (FDTD) method. Here's a possible high-level approach: