new use for blue Infinity

[JoeyL]

I was at a shooting range that had a light section and found a bunch of CMG infinity lights for $15. I bought one and in the process of checking it out and I realized that it makes UV light. It lights up fluorescent material including laundry detergent and a fluorescent dye we use at work. This is pretty cool.

Then I tried this with the blue photon and it seems it puts out UV as well. Theis is great since the UV photon is like $49.

Just thought you fellow gadgeteers might like this. It's great for invisible ink reading.

 

[sodakar]

woah... um, wow.

question is... is this true of any other blue LED light, perhaps?

hmm...

 

[Chris M.]

I find that most blue LEDs give off some long wave UV- enough to cause some dyes to flouresce. In fact the blue Luxeon Star I got today, causes the fairly dayglow-colour yellow and pink shades of a set of Xmas lights I have up in here (yes I know it`s not christmas but hey- I like lights!) to shine up brightly under its light.

ASP`s Sapphire does this quite well too. I don`t have a blue Photon or Infinity but I imagine they use similar wavelength LEDs (not to the Sapphire as it`s a deeper-than-normal blue, but to each other- and the blue Luxeon) so should work to some extent.


BTW someone on Ebay keeps selling UV Photons for $30 if you wanted the real thing. Search for UV Photon, or something like that- you should find them. He also sells regular Photon-2s starting at $10.

 

[The_LED_Museum]

The spectrum of most GaN on sapphire blue LEDs pretty much cashes it in at around 400-410nm. If you want some significant near-UV, get some Radio Shack #276-311 or other GaN on SiC types, and filter their output with Wood's glass, or glass from a broken blacklight bulb.

One way to EASILY see the difference between ordinary bright blue (like Nichia or Luxeon Star) and the whitish/violetish blue of the Radio Shack type is to shine both through the glass of an incandescent blacklight party bulb.
The Nichias and other GaN on sapphire (including Photon, Infinity, and Asp Sapphire flashlights) will show through as a dim, deep blue, while the Radio Shack model will appear as a brighter, vibrant violet color; since it has a much higher emission closer to 400nm than Nichia blues do.

The Radio Shack or other GaN on SiC blues that produce significant near-UV output (significant output from 395-430nm) can also be identified by two other methods:

1: When lit, the color will be a whitish blue with a violet tinge under some conditions.
2: Looking inside the bare LED (lit or unlit), you will see a small cubical LED chip with a single wire leading to its center, rather than two wires connecting at the corners of a much larger chip.

As for fluorescence being noted with Nichia LEDs and Photon, Infinity, and other blue LED flashlights, it is the blue light causing the fluorescence, not some amount of UV. Even green LEDs and green laser pointers will cause some materials to glow bright orange.
Shine a green Nichia LED or a green laser pointer at a day-glow traffic cone or a pink or orange Tektite flashlight body, and this will become apparent. They will also fluoresce with a blue LED.
The pink strip across the top of Priority Mail postage will also glow strongly under any blue LED, and to a lesser extent, to a green laser beam. So UV isn't necessarily needed to cause things to glow all funny.