CO2 laser optic

Hi to all.
I have a 60 watt CO2 laser at 10600 nm, and I want collimate the beam in a straight line, because  the burn power go down if I burn over 2 meters, the beam is most large.
-There is anyone that know the real beam divergence of this type of laser?
-There is anyone that has already do it?

Thanks

usually for a CO2 laser you use Zinc-Selenide lenses. The divergence of a beam is approximately the wavelength/the minimum diameter of the beam. I find it disturbing that you are trying to send a 60 watt beam over some large distance so I dont think I should answer this question.

I have two Zinc Seleneide lenses, in a Coherent "telescope arrangement". But also with this collimating system I ma not able to make the straigt line, perhaps I'm too near at the begin of the laser beam. The big problem is that the beam is invisible, and very very hot.
But already at 4 meters the laser has very low power to burn the wood.
At this moment the only way to burn is to put the object near the laser.

But don't worry. I want only make a "big" laser pointer. I'm not a criminal. ;D

Take a look around Ebay for a CO2 lens - ZnSe is the abbreviation for Zinc Selenide. It is a good idea to get the "working" part of the beam away from the laser itself, as smoke and cutting fumes could damage the output mirror. But I don't think you'd need to go more than a few feet.

The divergence of CO2 lasers is terrible - at about 15 feet the beam of mine is about 3/4" across, but as long as the beam diameter isn't bigger than your lens you could still focus it at that point.

Here's a link to a huge wealth of info on CO2 lasers (this particular link is about use and care of optics):
http://www.repairfaq.org/sam/laserco2.htm#co2opt

General info on CO2 lasers:
http://www.repairfaq.org/sam/laserco2.htm#co2toc