To anyone who cares, for my next project I want to try my hand at building my own cutting laser. I don't mean the cheap DVD player/mini-mag flashlight light matches and pop balloons thing. I want to use it to cut sheet metal and spot weld. I would be greatly appreciative to anyone who could direct me where to look. Is it possible to take a laser that is moderately powerful and mae it more powerful? Maybe a 1000mW laser? Can someone please help me with this?

To cut sheet metal (like steel etc.) properly you need a rather powerful laser. I'd say the "easiest" way to go about this is a CO2 laser..

 

The right lenses you can buy, making the power supply isn't probably too hard for someone who knows their electronics but making a good CO2 laser discharge tube out of scratch sounds pretty difficult even with the proper equipment. Of course, you can find these tubes on eBay so if you don't mind the engineering process being just the construction of the power supply then go ahead.

If you've got a CW laser you could convert it to be pulsed, this would increase the maximum power, but not the average power.

 

It's not that easy to build a nicely collimated high power laser system...

Sam Barros of PowerLabs got his hands on a CO2 tube a few years back and as a result some interesting stuff about optics, power supplies and cooling can be found here:

http://www.powerlabs.org/laser.htm

 

1) Buy tube on eBay

2) Build power supply

3) Build cooling system

4) Get a (ZnSe) lens for metal cutting

 

As noted on the page, you can drive the tube with excess power for better results but it will kill the tube faster than normal use would.