First, a bunch of classic turret designs: The Optic on one of those fork-mounts. You can probably have the laser generating thingy somewhere else and pipe the laser into the optic by fiberoptic so you can then focus it on whatever you need to focus it on. I imagine this is probably the first thing you think of doing if you're an engineer asked to design a laser-thing. You've got the minimal mass in the optic so target tracking is likely as fast as it is going to get.
For the slightly lazy engineer. Take the whole laser
system, put it in a pod, and then just aim the pod at whatever it is you want to shoot at:
This looks like a clever way to do your laser cannon. Fire the beam at a big ol mirror and just rotate the mirror to hit stuff. I
TWO Lasers. This wouldn't make the laser twice as powerful but there would be some applications. I imagine your pinpoint accuracy may suffer with having two smaller optics instead of one larger one but I also imagine you'd have an easier time getting acceptable accuracy out to longer range. Also using compound optics means your laser isn't taken out by a single hit.
Speaking of compound optics. Why not use a laser array instead of a big ol laser? Same problems apply, you might not be exactly as accurate but you just need to be accurate enough to focus on your target.
This one is cool just because it looks different. Probably exists to simply the engineering as with two bends like this you can more easily use a simple mirror to aim the beam instead of having to try and pipe things around with fiber optics:
'Enclose in transparent armored shell' is a good idea for lasers I think.
This one is probably meant for ground to ground communication since it isn't turreted in any way. BUT it does look like you can see the fiber optic carrying the laser. More powerful lasers might not work with fiber optics but it would be neat to see a bunch of different lasers optics being fed by a single laser generator like the multibeam frigate from Homeworld: Cataclysm.