Navy 25 kilowatt laser welder at Naval Research Laboratory

Largest commercially available laser of the 1970s; baseline for inferring Air Force classified laser power levels.

A guy at Naval Research Laboratory had a big 25-kilowatt laser back in the '70s, which was the biggest laser you could buy commercially. The Air Force had bigger ones, but you couldn't talk about them commercially. The Air Force's laser weapons back then were about 50 megawatts. That was classified — but you could figure it out by three different techniques in the open literature.