Learning Forum

[firdoust]

Hi, 

 

I am simulating the Invese taper design Inverse design of y-branch – Ansys Optics: 

 

How to replace the silicon material in the code "y_branch_opt_2D.py":

eps_in = Material(name = 'Si: non-dispersive', mesh_order = 2)

 

With a material of defined index? I am trying something like this but simulation doesn't work and gives me the error that index is not defined. 

eps_in = Material(name = 'Object defined dielectric', index=2.21)

 

Thanks,

 

[firdoust]

[daanish.peerkhan]

Hi Firdoust,

The error occurs because the Material class in the lumopt library does not have an index argument. It requires permittivity (base_epsilon) instead.To define a specific refractive index directly on the object, you should pass the square of the index (n^2) to base_epsilon and omit the name (it will default to automatically).Here is the corrected line of code:

eps_in = Material(base_epsilon=2.21**2, mesh_order=2)

The solver expects permittivity (epsilon), and the relationship is epsilon = n^2. By passing 2.21**2, you are providing the correct permittivity for your desired index. You do not need to explicitly set name='' as this is the default behavior when base_epsilon is provided.

Hope this helps!

Thanks,

Daanish