IR filter from a CD?!

[Zander]

I was playing around with some Memorex "Cool Colors" CD-R CD's (the red one is the one that gives this effect) with my green laser and I discovered that the part of the CD that touches the inside circle, as pictured below kinda works as an IR filter. That, or it just really, REALLY dims the light.

This is the CD I used with an arrow pointing to the part that I shined the laser through.


This is a close-up of that part.


This is the laser by itself on my wall.


This is the same laser through the CD (view the full size image to really see the difference).


I'm not sure if this thread is in the right section, sorry if it's not.

 

[Greenie]

Thats kool. Only with the red one?

Off TOPIC \/

I have this glass ball with some sort of light-purple metallic paint on it
that turns my green beam to red.

Any clue why?

 

[stevetexas]

"I was playing around with some Memorex "Cool Colors" CD-R CD's (the red one is the one that gives this effect) with my green laser and I discovered that the part of the CD that touches the inside circle, as pictured below kinda works as an IR filter. That, or it just really, REALLY dims the light. " - Zander

The only way to know if it blocks IR is to test it. I can say that it does block a lot of the green - sort of like the laser glasses (the color of the plastic is similar). Don't assume it blocks ANY IR though - some filters block only narrow portions of the spectrum.

 

[Zander]

I have no way of testing it but anyone can pick these things up at a Walmart or Target or any store like that for pocket change. Maybe someone why has the means of testing it could do that. Also, the black colored CD also does the same thing.

 

[stevetexas]

If I see one in my travels I'll grab one and check it out - good idea. If they're that cheap, the could be cut for filters as you suggested.