Laser breath is the breath weapon used by golden dragons. They are capable of using it in both their human and dragon forms.
Laser breath takes the form of a beam of light fired from the dragon's mouth. The laser cuts through physical objects with ease, and can damage astral beings like mazoku as well. The beam is quite powerful; it is seen to sink ships with a single hit in Slayers TRY, and destroys the entire headquarters of the Cult of Shabranigdu with a single hit in The Silver Beast. Its unique ability to affect physical and astral foes simultaneously makes it an efficient weapon even against creatures immune to most forms of magic.
The Zenaffa armor and Demon Beast Zanaffar both possess the ability to use laser breath as well. Ironically, as evidenced by the 16th novel, it is also one of their greatest weaknesses, as a reflected beam of laser breath can get around the armor's astral seal and deliver a devastating blow.