glow in the dark paint and frequency of light?

[ringi]

Hello, I was wondering if anybody will know if and than which "glow in the dark paint" will glow when exposed to infrared of ultra violet light.

Best

Ringi

[shreknow91]

first off Ir and Uv are on the complete oposite side of the light spectrum.
and secondly, i think all GITD items will glow under UV light, i am not sure about IR though

[ringi]

Hi, ok if i understand right the "black light" is a 370 nm. That is the best frequency to make the "flurosent paint" glow?

[Skylighter]

Yes, that 370nm (black light) is the near to the best charging light that is readily available.

[ringi]

Yes, i am thinking about trying to light up the flurosent with a laser diode. That is why need to find out the best frequency for the flurosent paint.

Thanks

[shreknow91]

well the most readily available laser that will florese (sp?) pretty much anything is a blu-ray laser that is 405nm

[Spacehead]

Yes, i am thinking about trying to light up the flurosent with a laser diode. That is why need to find out the best frequency for the flurosent paint.

Thanks

Ok I have to ask. What you are doing with a laser pointer and flourecent or glow paint?

[george blaha]

Yes I'm working on an art piece and also need to phospher the glow in the dark paint with a laser pointer. The answer seems to be to get a hold of a blu ray laser but when I looked they seem to be quite expensive. Any suggestions for a less expensive option? So the more common infa red lasers won't work to activate the paint?

[Oznog]

First Rule: the light's wavelength has to be shorter than a threshold to do any charging (shorter wavelengths have more energy per photon). If it's too long a wavelength, then it will not do any charging regardless of how bright it is. Also, shorter wavelengths than necessary (excess energy per photon) have no additional charging effect. One photon of the threshold energy or greater, one atom gets bumped into an excited state and higher photon energy doesn't get to do it twice or anything.

UV is wavelengths SHORTER than the visible spectrum, infrareds are LONGER wavelengths than the visible spectrum. IR is totally wrong, the opposite of what we need.

Zinc red is the ONLY type which can be charged with a green laser. And, BTW, the effect kicks ass. You can even mix in a little red with other colors and it doesn't show up strong and fades quickly under normal circumstances but hit it with a green laser and you get an awesome blazing track of red that fades quickly.

405nm will charge ANY glow power color effectively, it is visible as a purple color but does not appear very bright to the human eye which loses sensitivity in this area. 375 nm is mostly invisible to the human eye so you'd see a burst of the glow powder's color and little or no purple, however, it's potentially more dangerous to deal with an invisible, higher energy 375nm laser, and it may be harder to get a shorter wavelength laser with the same charging power as a 405nm (fewer photons).

What's the maximum wavelength? Well, blue LEDS are usually centered around 470nm but their actual emissions are a bell curve of wavelengths, around +/-40 nm but the actual amount of light is much lower once you get even +/- 20nm from the center. I can say that the blue LED has SOME ability to charge glow powders but it's not very strong because apparently only the minority of its light at the upper end is a sufficiently short wavelength to have an effect. But I can say 405nm is completely effective for sure!

Sorry but the reality is you need a blue laser but they're currently expensive. Most of those out there have been removed from a Playstation 3! Given time, they'll become more available and much cheaper. No one can say when. You can get them on eBay. But note that many "blue" lasers are indeed blue- ~470nm- and probably won't charge glow powder. You need 405nm.

You can use a <405nm LED to trace a line or dots on the surface, but it MUST be in contact with the surface or you'll get a wide, fainter area. An LED can be focused into a "sort of" narrow beam with the right optics but it'd be pretty extreme optics (large, and carefully chosen).

All this is a limitation of the physics and we can't change physics, you'll get the same answer anywhere.