If you still want to keep the thick design but not waste photons, integrate more barrels. It'll work a lot better than the huge barrel idea before, while keeping the same size.
This will increase heating, efficiency, and the more compact design is better for people to use.
Again, you need to understand that frame or insulator will prevent overheating. The converter helps with nothing. As for the powered clone, you're producing a lot of photons for nothing. If you want to, you could widen the "nozzle" which would give use to the wasted photons, but greatly decrease efficiency. If you want to keep the sigle barrel, I recommend making the laser thin enough for only one line of powered clone.
If you still want to keep the thick design but not waste photons, integrate more barrels. It'll work a lot better than the huge barrel idea before, while keeping the same size.