Not lasers, but lots of fun in a different and scary kind of way.
I am currently working as a test & commissioning engineer for a company that makes RF induction furnaces. The power supplies for these things are quite scary. We take lots of 3 phase, rectify it into DC, pass it through a big choke and a bank of thyristors and end up with 800V DC @300A, which is switched at about 10KHz, passed through a big coil and makes things very hot. To keep things in check, the power electrics, choke and bus bars are water cooled at 5 bar pressure. It kind of reminds me of playing with big argon power supplies and brings back happy memories.
Anyway, we have been playing with an experimental design and have run into a couple of hiccups along the way. During the latest test, we trashed the bottom plate of the furnace and managed to weld a 12mm thick, 200mm diameter graphite tube to stainless steel. That plate is an inch and a half thick billet of 310 stainless. Its also warped and about 3mm at the edges.