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General properties - reflection and transparency relation

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Jabberwocky

Mechanical
Apr 1, 2005
330
Ok let's try this question again. I'm only referring to visual light for simplicity.

(stop me if I'm wrong here)
The material property transparency measures amount of light that can pass through said material.

The material property reflectivity measures the amount of light that will coherently bounce off said material. I say coherently because I know all visible objects reflect light, else we'd never see them...

My question is, are these two properties inherently linked?

You can wax a car and get a very reflective, shiny surface but you can't see through the hood (0% transparent). Glass, quartz, water, etc. all seem to be both transparent and highly reflective. Is there a material that is highly transparent but not reflective?
 
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the transparency is bulk phenomenon , the adsorption
is increasing with thickness.

The reflection depends on the surface.


<nbucska@pc33peripherals.com> omit 33 Use subj: ENG-TIPS
Plesae read FAQ240-1032
 
Right, the thicker the material the less light will make it through to the end.

And yes reflection requires a highly polished surface as opposed to dirty scratches and the like.

Can you have a dull finish, due to light scattering, and still have transparency letting light through to the other side? The closest thing I've seen to such a material is translucent concrete - shown here:

 
Why do you think that finish has anything to do with transparency?

Frosted glass has about 50% transmittance and a dull finish. Mirrors have smooth surfaces, but so to the lenses of a telescope.

TTFN



 
What about fiber optical cable? It may be only millimeters in cross section, but can be VERY long. How do you define thickness in that case?
 
As for highly transparent and not reflective, that's basically anti-reflection (AR) coated optics

TTFN



 
Ok, AR coated optics - those are neat and seem to work as I'd imagine such a thing would have to.

Thanks all.
 
Gold coatings are quite common in controlling both the transparency, transmission, and reflection of a substrate.

One of the better examples is the Astronauts Helmets.
 
It seems to me that reflection is inversely related to transparency. If light is being transmitted it isn't being reflected, and vise versa. There are new glasses that minimize reflectivity and maximize transparency somewhere in the neighborhood of 95-99%. I have seen it installed in a new office and there is a substantial difference.
 
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