Well you don't need anything special for safety goggles for co2 lasers. A normal pair of glass or acrylic goggles will work fine, since pretty much EVERYTHING is opaque to 10600nm. Plus the danger with them isn't really hurting your retina's, since 10600nm won't pass through the cornea either. The danger is from burning your face off.
And as far as the original question. Yes, a CO2 laser is going to be about the only relatively cost effective *laser* based method of cutting something that thick. Though 10W probably wouldn't work. You'd likely need 50W and up to get any kind of decent cutting speed.
Wouldn't the required power be dependent on the ability to precisely repeat the pattern being cut ?
If you were to use a lower powered laser and make multiple passes wouldn't the end result be the same ?
And as the scorched/blackened wood might absorb the energy a little better on the subsequent passes (or would the air-space riddled structure of carbon actually inhibit the energy absorption ?) the limiting factor should be the ability to focus the energy on the same place exactly.
Just a thought...
Faster cuts = less thermal stress on the work piece, keep that in mind as well. Also, it will help production time. A 10W CO2 laser isn't much cheaper than a 40W one. They're one of the simplest lasers to get running as well. Initial investment shouldn't be more than $400 for a truly basic set up.
Yeah I understand the concept although I don't think that thermal stress on 3/8 plywood would be much of an issue as long as you are including a simple fire prevention system. (Like compressed air blowing at the point of "cutting" removing debris and cooling the area at the same time.)
I'm just looking at it from a cheaper hobbiest viewpoint...like the other post about making shallow engravings in dark plastics using a higher powered "projector". If you could draw the image slowly and after correcting the beams with lenses before the galvos to optimize the beam parametres for the distances used.
The concepts for both have some overlapping ideas/theories that could be exploited by the home hobby builder. Both would be great exercises for honing one's building skills. Neither would be the best solution but there are a few people who don't like to do things the same or the easy way as everyone else. And then there are a few who have their own reasons for doing it whether it be equipment availability or financial investments or whatever.
But I think I am digressing from the OP...