Direct diode bar lasers - http://www.industrial-lasers.com/articles/print/volume-29/issue-3/features/high-power-direct-diode-lasers-for-cutting-and-welding.html
60W laser diode running SME - YouTube _ [1]
Laser kit, 200W, from Nufern for experimental use - [2]. Potentially perfect OSPD collaboration if guarantee market for 1000 devices.

Design

Neodymium-doped solid state lasers continue to be the laser source of choice for industrial applications. Direct pumping of the upper Nd laser level at 885-nm (rather than at the more traditional broad 808-nm band) offers the potential of improved performance through a reduction in the lasing quantum defect, thereby improving system efficiency, reducing cooling requirements, and enabling further TEM00 power scaling. - [3]

Doc

1070nm fiber laser - [4]
CO2 laser appears to be used more for thicker steel, fiber laser for thin steel - [5]
How fiber lasers work - Fiber lasers belong to the solid state laser group. They generate a laser beam by means of the "seed" laser and amplify it in specially designed glass fibers, which are supplied with energy via pump diodes. With a wavelength of 1.064 micrometers, fiber lasers produce an extremely small focal diameter. As a result, their intensity is up to 100 times higher than that of CO₂ lasers with the same emitted average power. - [6]