Ultraviolet LED supplier suggestions? 1

[jasonh]

I'm looking for recommendations for ultraviolet LED supplier sources for ~370nm, 1-5mw@15-20mA, with two variations; one with ~110 degree view angle, another with ~30 degree view angle. I would appreciate any recommendations, but I prefer a US company or at least one having a US location.

 

[busbar]

Possibly ledmuseum.org

 

[Lewish]

I never heard of anyone making a UV LED. Blue was hard enough to accomplish. I can't imagine anyone having done a UV unit.

Please let me know if you succeed in finding any. I could use one also.

 

[busbar]

See:

http://ledmuseum.home.att.net/leduv.htm

290-395nm Ultraviolet

 

[jasonh]

Thank you for the reposonses so far.
Ledmuseum has some very interesting testing info, which identifies the manufacturers name of the LEDs tested.
Thus far I have identified the following as UV LED manufacturers:
*Roithner-laser (noted at LEDmuseum) 350nm, 380nm, 394nm
*LEDTronics (noted at LEDmuseum) 395nm
*Nichia (noted at LEDmuseum) 375nm, 370nm (strong cautions about UV light damage to the eyes)
*Wilycon (noted at LEDmuseum) 395nm
*Bivar 400nm
*Toshiba 380nm
Roithner seems to be "leading the pack" in the UV offerings, but prepare yourself to pay big $.

 

[robt]

This site offers a 10 deg and a 110 deg UV LED:

http://www.theledlight.com/led-specs.html

 

[SteveBzzz]

Question:

This may be a silly question, but why can I not find a super cheap source for Red Laser Diodes (Used in Laser Pointers). I can get a laser pointer for about $2 with small quantities. Can I just "remove" the laser component from the laser pointer? Is there a difference between the laser in a laser pointer and the laser diodes you buy?

Also, is it possible to filter out all of the visible light that is emitted from a black light, so that only the UV part gets "transmitted", and you will only be able to see reactive items? Hmm...maybe I'm thinking wrong. What actually causes the florescent material to glow, the UV component, or the visible component or both? Would it still glow if you removed the visible component. In other words is there a black light or UV light that is in the range of UV but below visible?

OK thanks, (Cheap laser diodes, and UV question)

Steve

 

[IRstuff]

The fluorescence comes from UV excitation of electrons that then emit visible light photons for you to see. There are commercial black lights that block pretty much all of the visible light output, but anything more exotic will cost you large $$.

TTFN

 

[jasonh]

I believe that the LED in a laser pointer is pretty much just a standard LED, and that the prism attached is what makes it into a laser.
There may be a way to filter the light coming from a red LED, to obtain only the UV component, but I expect the resulting UV component would be very low in magnitude.
There are UV LEDs available at quite a wide range in price. A UV LED has a wavelength of approximately 370nm, the further you get away from 370nm, the more visible light present. You will find LEDs close to 370nm (e.g. 384 - 410nm) but there will be a degree of blue light.
I have found that Bivar seems to offer the cheapest UV LEDs.

I hope this helps,
Jason

 

[nbucska]

JasonH:

The LE (light emission) action is the same in LED and
LASER but the laser action is missing in the LED i.e.
there is no "stimulated emission" etc.

<nbucska@pcperipherals.com>

 

[IRstuff]

Going with a UV LED may be bad for other reasons. Typical fluorescence behavior requires some specificity of UV wavelength to excite the mode. You may need to explore what you are trying to illuminate and identify the specific wavelengths that excite the fluorescence. Otherwise, you'll not only get a dark room, but no fluorescence either.

TTFN

 

[jasonh]

All very interesting and en-lightening (pardon the pun) views today. nbucska and IRstuff obviousely know much more than I do about lasers and UV LEDs. Thank you for the info.
Just FYI, I am using UV LEDs to illuminate &quot;invisible ink&quot; that was purchased from Sirchie police supplies

http://www.sirchie.com/section10/uv734.asp

Jason

 

[busbar]

Maybe:

http://ledmuseum.home.att.net/leduv.htm

http://ledmuseum.home.att.net/menutop.htm#7

 

[electrogap]

SteveBzz,

I asked myself the same question, and I do not have the answer. Perhaps because of the law of big quantities. The thing is that if you try to buy a LASER LED , you still need lenses to colimate it and all this can end in 15 to 20 bucks plus all the hasle of the optical aligment and mechanical support. I've got the laser pointers from ebay for 99 cents each, then using a hack saw I carefully made a longitudinal cut in order to break the aluminun cylinder open. Then you can take the small board with the switch and the LED, the lense is also attached to the board.Weld the power cables , they work out of 4.5 volt, and they are ready for any application.For robustness, I enclosed it inside an acrylic cilinder 3/4&quot; OD and the ID fits perfect with the brass frame of the lense.

Good luck..... JGV

 

The laser diode thing is a bit off-topic but here's a note. In order to produce a parallel light beam you either need a source emitting such a beam directly (such as a gas laser) or a (virtual or real) point source, such as a laser diode. The former is a virtual point source at an infinite distance.
Optical law has it that you can't collimate the light from a finite-sized source onto a point or into a parallel beam. What lasers do using their mirrors is amplify light rays that are perfectly perpendicular to the mirrors (because they can keep bouncing up and down for a long time) while hardly amplifying anything that is not perfectly on axis (because such a light ray will quickly escape from between the mirrors).
These 2 observations both suggest that lasers are the only way of achieving parallel beams or diffraction-limited focus.

You could recuperate the lds and optics from scrapped dvd drives. I'm eagerly awaiting high-speed dvd-ram drives to arrive on my scrap heap: 635nm at 35mW yay!