Next to the photon beam, place some life particles (seed, gnarl, replicator) sorounded by void. They will generate tons of heat and heat up the laser to possibly 9750 C.

If you have trouble with the powered-clone, try putting an ordinary clone and putting a E-Wall where the photon hole is.

Use CLNE(PLSM) or Replicating GOL. For the melting PSCN just put it one block away from the PCLN, and surround it with SHLD.

@Lagnadium41 Sorry I couldn't show it to you earlier, here is a save I prepared which should help a bit:

Remember for stamps: Copy is Ctrl C , Paste is Ctrl V , Save is S, Load recent is L, Load selection is K, move up a pixel is Up Arrow Key, move down a pixel is Down Arrow Key, move Left a pixel is Left Arrow Key, move right a pixel is Right Arrow Key, Rotate is Ctrl R , Flip is Ctrl Shift R and most importantly, Zoom is Z (magnification is adjustable using [ and ] ).

BTW, it is impossibly hard (if not impossible) to reach max temp using gol. Use other heaters I showed you instead.

Also remember that you can activate powered elements (like pcln) with pscn placed orthogonally and spaced with one px of empty space in between the powered element and pscn. Likewise, nscn functions similarly but instead deactivate powered elements.

Powered elements also influence other similar elements when there is one px of empty space between them (except diagonally) . I.e., turning on pcln will turn on a neighbouring pcln even if there is 1 px empty space in between them.

These are useful to know when positioning your laser's switches.

you can surround your buttons with insl as pcln will recieve spark right thru the insl.  

The heating element does not have to touch the void in the first place. I used to like putting additional pcln to "conduct" the on state, but I don't do that for photon lasers. Vaccuum with clone cloning plasma in the middle works great as a heating element, or pump+uranium. Life only heats to about 8700° C, so it does not heat up to max. temp.

Here is an example of the first laser I posted.

And here is an example of a laser that uses pump+uranium to heat photons to over 9000.