Whats the IR diode in the dvd burner sleds?

[tocket]

You can actually make a wide spectrum of colors from 780 nm. There's a phenomenon called upconversion that allows the transformation of near infrared light to visible light. Note that this is a completely different process than frequency doubling.

Erbium(III) absorbs well at 780 nm, and being a lanthanide it naturally has some interesting optical properties. Pumping it by 780 nm it is possible to get emission in the UV. Using different fluorescent dyes it is then possible to get any color.

Of course, it won't be a laser (well, the erbium(III)-glass might lase under the right conditions), but still...

[keeperx]

well there ya go.. now we are talking.. something interesting to do with them..

[stanwax]

so if i started with a broken cheap green laser i could swap out the crystal and the IR diode and make it blue?

Yes and no. Blue is still pumped by 808nm but uses different xtals (YAG coated for 946nm and LBO instead of Vanadate and KTP) So yes you could by replacing most of the parts! (you would need a different OC to) - kinda pointless and expensive and you will struggle to get any significant output as the blue wavelengths need pretty specific temp conditions to achieve effeciency

Rob

[tocket]

One glass for upconversion (LiTeO2:Er3+) gives emission at 380, 530, 551 and 654 nm when pumped by 780 nm light. Very interesting stuff. Unlike frequency doublers these materials are not very picky about what you shine at them.

I've yet to see a glass like this in real life though. I'm looking forward to that day.

[mixedgas]

or you could scan it on a upconversion phosphor.

Somehow I dont like the idea of flinging 10's of mw of IR around the room, but you could scan it on this:

http://www.altechna.com/product_deta...ils.php?id=299

AKA IR cards. I just picked this one because it was the first to show up on google

Steve