Hi @Luca.cellerino,

I don’t know these kind of materials/properties, but looking at your screenshot, you basically want your material to exhibit a transmission that is a function of the incidence angle and material thickness, is that right?

I also don’t understand what you are doing with your Merit Function.

But here is what I can suggest based on my current understanding of your problem.

You could use a ZPL solve on a dummy cell of the LDE, the solve would read the thickness of your surface, and based on this thickness, it selects a coating that has the right transmission.

Here is an example where I set a ZPL solve on the Chip Zone. The solve looks like so:

# Surface from which the solve is called
surface = SOSO(0)

# Corresponding surface thickness
thickness = THIC(surface)

# Change coating depending on thickness value
IF (thickness > 2.5)
	SURP surface, COAT, "I.98"
ELSE
	SURP surface, COAT, "I.95"
ENDIF

# Dummy return
SOLVERETURN 0

This means that on the surface where the solve is, it’ll retrieve the thickness value, and if the thickness is strictly greater than 2.5, it will apply an ideal coating with a transmission of 98 percent. Otherwise, it will put an ideal coating with a transmission of 95 percent.

In your particular case, you’d have to have multiple coatings that include the transmission as a function of the incidence angle (perhaps with a TABLE coating) for the different thicknesses, which is more complicated, but you could use Python/MATLAB to automate the generation of those coatings. You will also need a more elaborate IF-ELSE statement, again Python/MATLAB can help to write the ZPL code automatically.

Let me know if that makes sense.

Take care,

David