This is a flashlamp pumped Ho:YAG laser, much like my VersaPulse laser system. It was rated to do 8W with a 5Hz rep rate (ie 1.6J) with a 250uS pulse length (6.4kW pulse average power), and I suspect that with the fiber coupler removed it is doing close to 10W, although I have not had a chance to put it on the power meter yet.
The power supply and pulse forming network, which is a Analog Modules 880-136T (which appears to be a custom supply, which does not match the pinouts given for their other flashlamp supplies). Inside it has a large 2kV 175ufd capacitor, 2 unmarked capacitor charging supplies, a large inductor, scr, control board, and an analog modules simmer supply. The simmer supply is marked model 816-19, which while not not listed on the analog modules site looks identical to the 86X series of simmer supplies, except that it has one extra pair of control leads which are unmarked. They appear to set the simmer current, and have 1.6v across them when connected to the laser's computer.
A shot of the output optics from the laser, and the laser brick itself. As laser heads go this one is fairly simple, it has 2 intracavity shutters, an extracavity shutter, trigger coil to fire the lamp, power monitor photodiode, some interlock switches, and the fiber coupler assembly.
This laser was designed for surgery, but since my roomate was out town while I had it running (haha) I had to use it on some inanimate objects I had laying around instead.
A shot of the laser focused on a piece of .030" thick steel, from the front and the back (note-the front on picture was taken though a filter which gives a green hue, and the double image was because the laser fired twice in the exposure and the camera moved between the 2 shots)
Some shots of a poor piece of plastic
One interesting fact about Ho:YAG lasers is that the 2100nm radiation is absorbed by water, which allows on to do things like vaporize holes through ice as above (from the front/back)
A shot of the laser being fired on a piece of aluminum plate, and a mirror that got a speck of dust on it. It didn't take long before damage grew to the full diameter of the beam (4mm) and toasted the optic.
I successfully reverse engineered this power supply and head pinouts for this laser, so if you happen across either of them send me an e-mail and I will see what I can do to help. firstname.lastname@example.org