And to create a straight photon laser, you just surround a pixel of PCLN with ctype PHOT with VOIDs except for in the direction the laser points to:
Note that you must spark the PSCN to turn it on, and NSCN to turn it off.
To make a laser of protons, pass the photons through HYGN like jacob1 said
For a neutron laser, pass them through INVS
And for an electron laser, pass them through BIZS (not accessible through the regular elements menu, you must either heat up some BIZR, or simply press E, which brings up the element search)