Material opaque to IR but transparent to visible light

[refind]

Hi all,

I want to get some sort of polymer that is opaque to infrared (absorbs wavelengths above 700 nm very well) but transparent to visible light (does not absorb much light below 700 nm).

Does this even exist without being a meta material?

 

[Vanadium 50]

What's wrong with glass with a blue filter on it?

 

[refind]

Thanks. What is the blue filter? What material is it, are there any links you can point me to? I appreciate it.

 

[Andy Resnick]

Hi all,

I want to get some sort of polymer that is opaque to infrared (absorbs wavelengths above 700 nm very well) but transparent to visible light (does not absorb much light below 700 nm).

Does this even exist without being a meta material?

Is there a reason you want it to absorb instead of reflect (google 'hot mirror')?

 

[Vanadium 50]

What is the blue filter?

It is a light filter that is blue. If you Google "blue filter" there are 610 million hits.

 

[refind]

Is there a reason you want it to absorb instead of reflect (google 'hot mirror')?

Hot mirror is a great suggestion. I just want to make an area invisible to an IR camera but visible to a normal camera.

By the way I was googling around and someone says to spray Copper II sulfate on a piece of glass and that will do the trick. I don't mind the blueish tint and I might give it a try. Does it sound like a bad idea?

It is a light filter that is blue. If you Google "blue filter" there are 610 million hits.

I didn't know blue colored plastic/glass will necessarily absorb IR. Thought it would just absorb visible red. I'll give those a try too, got an infrared LED I could see with my phone camera to test it out.

 

[DrDu]

What range of IR?

 

[Andy Resnick]

What range of IR?

Excellent point:

I just want to make an area invisible to an IR camera but visible to a normal camera.<snip>

http://ashwin-ushas.com/developed-technologies/infrared-electrochromic-skins-for-dynamic-camouflage/
http://www.uasvision.com/2011/06/10...mager-reveals-camouflaged-and-hidden-objects/