May I just say, looking at your picture and reading your description, it's really only a short step away from a true ray gun. That shiny metal casing is just dying to have a pistol grip handle attached to it.

Or even better, you could mount it inside one of these.

On the other hand, you already said that it has a limited focal point, so what it truly needs is a proper collimating lens. You could mount the collimating lens on a sort of extension, making it truly look like a ray gun, such as this or especially this.

*drool*