Scattering cross section of a nanoparticle on a substrate


I am trying to simulate the scattering cross section of a 40 nm gold spherical nanoparticle placed on a silicon substrate . I only need the scattering from the nanoparticle and not from the substrate as I am using a dark field microscope in my real experiment. could you please help me on this?

The image attached is just for explanation it is not what I am using.


I suggest using a Total field scattered field source and set its end just above the substrate. This way you will only take the effect of the particle on scattering.

But there is a point I can’t understand in your question. Actually, I expect the light to be trapped between the particle and the substrate so why would you like to ignore the effect of the substrate??


Hi Aya,

Thank you for your reply, this is really helpful.
I actually just interested in measuring the scatter cross section from the nanoparticle and check the effect of the substrate on shifting the peak resonance. But I also need to check the field profile at the gap with the substrate. So in this case do I need to run two simulations? like one with the TFSF just above the substrate to see the scattering cross section and then extend the TFSF to the substrate to measure the field profile at the gap?


You are welcome. In this case, yes, you should run 2 simulations.
In the first one: disable the substrate and measure the scattering cross section.
Next, run another simulation and see the enhancement in the scattering cross section or Electric field.

For the sake of completeness, the best way to do this is to use the TFSF source and scattering analysis group. For an example of how to do this, have a look on this post.

Let me know if you have questions :smiley:


Hi Aya,

Will the effect of the substrate on the nanoparticle cross section will be included in the results from the simulations? as I need to measure this with different substrate materials.



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