|Message: Behaviour of unified model for backpainted surfaces||Not Logged In (login)|
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I have been trying to trace photons impinging on a polishedbackpainted surface, and I have a doubt on the exact mechanism of interaction at this boundary. For what I had understood:
- The photon comes at a polished interface and gets reflected, refracted or totally internally reflected following the Snell law (in this case the parameters into play should be the index of refraction of the volume and that of the wrapping surface). - In the case it gets refracted, it "enters" in the thin slice of the border surface. Here, depending on the probabilities specified for every type of reflection (lobe, specular, etc.), the photon is reflected back to the volume.
Though, in the case of a polishedfrontpainted surface the photon gets simply and only reflected.
As an example: - let us imagine a photon coming from a medium with index of refraction 1.8 to a wrapping with index of refraction 1 and a surface defined as polishedbackpainted (and completely diffusive). In the case the photon impinges on the surface with an angle higher than that for total internal reflection it gets reflected back. Otherwise it enters the wrapping and is diffused. - if, as a countercheck, we set the index of refraction of the wrapping surface at 1.8 (the same as the bulk volume), the photon always crosses the surface and gets diffusely reflected by the painted surface.
Is that correct?
Thank you, Nicolas Di Vara
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