Pulse laser turret

The Pulse Laser Turret is a Covenant starship weapon that can fire on both space and ground targets. These turreted beam weapons are known to have been mounted on Covenant Destroyers, Covenant Heavy Cruisers, and Covenant Carriers. Strangely enough, UNSC Prowlers also have these energy weapons: highly unusual, as United Nations Space Command starships typically utilize projectile or explosive weaponry. However, it makes sense that since ONI is the group responsible for reverse-engineering Covenant technology that their ships would be the first to reap the benefits.

Physics
Before the weapon fires, it must first charge, during the charge a sphere of light energy forms at/around the charging weapon. After it is finished charging, it expels a cyan beam of energy. According to the Halo novels, a section of the ship's shield must first drop to let the weapon fire.

Damage
The weapon is said to have reduced the UNSC frigate Commonwealth's armor in sections three and four to a quarter which would mean (as frigates are known to have 60cm-thick armor) that a pulse laser salvo is capable of melting through 45cm of titanium A battleplate in mere seconds (meaning that at least it is able to transmit apx. 3.6x10^6 joules of energy). This means that pulse lasers pose a serious threat to UNSC frigates (and presumably smaller and lighter armored UNSC ships) as it only takes one salvo to melt through parts of its armor. However, it is believed that larger UNSC ships with thicker armor would have to take multiple pulse laser salvos to show the same results. In Halo 2, what is presumed to be a pulse laser is seen gutting a UNSC cruiser in a single blast.