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Simulating Opal Diffusing Glass - Diffuser

  • 8 September 2021
  • 3 replies
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I’m interested in using non-sequential environment to simulate this Opal Glass diffuser from Edmund Optics: https://www.edmundoptics.com/f/broadband-hybrid-diffusers/34772/

It’s a bulk scattering substrate with grit 120 surface on both sides for improved NIR wavelength scatter since the bulk is optimized for visible wavelength scatter.

I’m quite unfamiliar with how to go about it and through searches on google and here didn’t find anything similar that I could replicate.

An example project of the hybrid diffuser would be extremely helpful.

Manufacturer doesn’t provide ZEMAX files for this.

  • I don’t know what bulk material to use. N-BK7? Something else?
  • Which bulk scattering method to use? Any guesses on the parameters for that method that would be reasonable?
  • How do I simulate ~30% transmission of this type of diffuser, presumably the rest of the light is backscattered or absorbed, not sure how much of either happens?

Thank you

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Best answer by Sandrine Auriol 9 September 2021, 15:33

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Userlevel 6
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Hello Andrey

I think a first step could be to contact Edmund Optics to see if they have any more information they could share to model this kind of objects. I did a little research on our side and didn’t find anything similar.

In EO article, they mentioned that the diffusing Glass is a colloidal material that utilizes the Tyndall effect to scatter light: https://en.wikipedia.org/wiki/Tyndall_effect. In the wikipedia article, there is a comparison with the Rayleigh scattering so I guess a 1st step can be to review bulk scattering models like Mie/Rayleigh scattering to start with and see if this can be a 1st approximation. 

Here are a few references to read:

Sorry for the short answer but do not hesitate to ask again.

Userlevel 1
Badge +1

Thorlabs provides BSDF data for their ground glass, although it’s not easy to find on their website.  Go to the ground glass diffusers page.  Under the Graphs tab, you’ll find the BSDFs and a link to a spreadsheet of the data that can be input into Zemax.

Userlevel 6
Badge +2

Thank you @Donna.Waters ! This is definitely interesting. I have shared a DLL that we had in house that can be used to easily model these kinds of BSDF in Zemax: 

 

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