get an near-infared one, it wont be very visible at all, like a .5mw red and it will have bad beam specs but it is 1w and they are only about $50, they are not good for long distance burning but you can focus them down to a tiny dot at say a foot away and they will burn like no other.
Although those are the cheapest diodes and there new they arent really the best burning power, they do burn quite good but they come from a 16x dvd burner, if visibility is what you want you would basicly have to go with a 20x dvd burner or a 24x tho ive never seen any of those but i guess they exist.
If all you want is burning tho i would still go with the ir its the cheapest mw-per-dollor your going to find.
@Frothychimp: If he says that, I doubt he would even be able to get one running, were you to give him the parts needed. I think getting a CO2 to fire requires some knowledge (which I haven't and ths can't actually judge, but they do seem a bit more complicated).
Since this question isn't answered: A CO2 laser is a laser that uses CO2 gas as the lasing medium.It outputs coherent light of 10.6µm wavelength. They're easily obtainable in multiwatt form, and they're the choice for industrial laser cutting, etching and engraving.
Well, there are many powerful IR pump diodes that you could use for burning. However once you get above about 150mW it's very hard to find ANY diodes that are single mode. Most high power pump diodes (> 1 watt) are not single mode .. this is fine if all they are going to be used for 'pumping' the crystals of a DPSS laser, but these multimode diodes would not make the greatest burners because they cannot be easily focused to a tight spot.
Honestly you aren't going to do better than the SenKat (Sony 16x) diodes.. for about $20.00 you get a single mode visible diode that be easily pushed to 150-200 mW. Since these are single mode you can focus them to a nice tight spot using simple optics.
Again, there are higher power diodes, but most of them are in the IR (not terribly visible), and most of the high power ones (> 1 watt) are not single mode. And you can bet they are going to cost more than $20.00 each.
Check out Roithner lasers.. they have a large selection of high power diodes.. most are not single mode. Don't ask on the prices.. http://www.roithner-laser.com/
[quote author=FrothyChimp link=1199586568/0#7 date=1199592453]I hate to say it but if you have to ask what a CO2 laser is then you should not have one. They are way too dangerous for inexperienced enthusiasts.
Hurt ?? Burn through skin ?? A true show of the lack of modration here relating to our hobby. As with many aspects of science, "hurt" can be accomplished if not used with wisdom.
Feeding this sick child advanced knowledge exhibits poor moderation on the part of our members.
I will no longer post any of my results or science to this forum. I don't want to contribute to the "hurt" in our society.