IR and UV glass.

[rathat]

So if glass absorbs high uv and ir and only allows the visible spectrum to pass than would that black plastic in the front of remotes be clear if we could see ir?

 

[Foobario]

Yes.

And, interestingly, if you were to use that same black plastic to make a lens, it would focus the IR the same way glass focuses the optical wavelength.

I used to work for a company that made motion detectors... mounted in front of the IR sensor was a piece of plastic that looked a lot like a Fresnel lens, but it was black plastic. Turns out that IR is refracted by the black Fresnel lens exactly like light would be by a clear one.

 

[rathat]

Regular glass wont block low ir like from a laser right? And what about acrylic? Would that basically have the same properties?