I implemented a SW laser effect in my game. It probably isn't what you're looking for but I share it nevertheless because it's a quite efficient trick.
A laser beam or laser saber in SW is in fact easy to reproduce with 2 cubes (testcube) of different color (like red ans light pink) and both superposed. And setting both material to inverted faces gives this typical shape of the laser. CPU Cost: only 2 cubes.
After that, I stopped there but you can maybe implement a blur shader to make a better effect. I've alas no knowledge in shaders.