Index Perturbation material not getting applied to object

holdmanholdman Member Posts: 1

I'm simulating the effects of doping on the spectrum of a Si object. In my simulation, I have a TFSF source incident on a 500 nm square Si rod. I measure the scattered power with a box of power monitors.

I created a material Index Perturbation material called "Si (Silicon) - Doping", which uses the Soref Bennett model of np density perturbation. The base material is set to "Si (Silicon) - Palik". I wasn't seeing any changes in the spectrum for any values of "test value p", so I decided to include the temperature effects as well at a very high temperature (T=1000 K). The material explorer clearly shows that the perturbation is getting applied to the material itself (even though it is physically unrealistic). The index raises to about 25.

I then created a sweep "int_vs_dop", which just changes the object's material from "Si (Silicon) - Palik" to "Si (Silicon) - Doping". However, when I run the sweep, the spectrum does not change whatsoever between the two.

To confirm this, here is the difference in the spectra.

It seems the material is not getting applied to the object. Is this a known issue?

I would like to upload the fsp files and lsf files, but I get a warning that they don't have an allowed extension.


  • kghaffarikghaffari Posts: 69Ansys Employee


    Thank you for reaching out. The test values set in the index perturbation material will only impact the material explorer values (for demonstration purposes) and will not influence your simulation. To model the effects of doping on the optical simulation you will also need to use the “np density” grid attribute, fed with charge profile .mat data in the region of interest.

    I would recommend taking a look at the MODE simulation setup in the pn phase shifter application as an example. Sharing files is not allowed here, but hopefully this will resolve the issue.

    Kind regards

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