Learning Forum

[Syahidah Mohd Khairi]

Hello, I am trying to include ITO coated slides to study my assembled material optical effects using Lumerical FDTD. However, I am not sure which material type to choose to input the ITO coating refractive index and conductivity.

I initially used Conductive 2D to include the conductivity on a 2D rectangle, but it appears to have refractive index of 1 as shown by the refractive index monitor (it shows up in the monitor for conductivity). 

I am thinking to use Conductive 3D to include both conductivity and permittivity (converted from refractive index), but the permittivity is a single value, which would not include the frequency-dependence. This would be important since I am simulating multiple frequencies (broadband source).

Is there any option in Lumerical FDTD to include both conductivity, and frequency-dependent permittivity or refractive index?

[Greg Baethge]

Hi, thanks for posting your questions. a dispersive permittivity can only be set for a sampled 3D material. In the conductive 3D material model, the resulting permittivity is frequency dependent according to the formula (taken from the documentation)

The question is whether this really corresponds to the material properties you are looking for. Unless you're dealing with a 2D material (where the thickness is much smaller than the wavelength), I don't think using a 2D conductivity model would work.