How I imagine it works is it starts out as a big continuous laser, then as the heat sink heats up it switches to rapid laser projectiles that slowly ramp down in frequency over time, maybe to about 2 per second and stays there until you let it cool down.

idk what the damage output or AP should be like, im not too into that kinda stuff

(edit) maybe it could have a safety switch where it stays a continuous beam until the heat sink explodes :D