I need a very unusual UV filter (no, not what you're thinking)

[Arkasha]

Hello,

I want to show my class how tonic water will fluoresce under UV light. My UV sources are a couple of 12V UV bulbs, as designed to "pimp out" (don't ask) a PC.

Here's the main problem: these also put out some visible wavelength, purplish light. I'd like filter this visible light out, so my students don't think the fluorescence is somehow just a reflection of the emitted (visible) light.

Can anyone suggest a material that would effectively render these lights truly "black?"

Thanks in advance!

 

[Edgardo]

Maybe a green foil or glass helps filtering out red parts of the light.

Or you could buy a filter, for example from Edmund Optics:
http://www.edmundoptics.com/onlinecatalog/DisplayProduct.cfm?productid=1924
I would suggest the BG-12 filter for 22 Dollars.
The bottom graphics shows the filter characteristics.

 

[Arkasha]

Thanks, Edgardo. Very useful information, so I can shop around for larger sizes.

 

[Edgardo]

You may also call their technical support. They will surely help you.