Laser weapons were weapons that utilize lasers, a directed light technology that compressed photon particles into a beam that could have heat and blast effects. While many spacefaring species used lasers in other means, such as in optical data networks, few used them as weapons by the 23rd century, since a variety of exotic subatomic particles could be used to create a more powerful beam, that duplicated lasers in use, but increased the weapon's effectiveness.
Starfleet crews used laser weapons in 2254, around the time USS Enterprise visited Talos IV. Landing parties carried laser pistols and large laser cannons were available as heavy artillery. (TOS: "The Cage")
By the 24th century, only a few races still used ship-board laser weaponry, including:
- the Atlec (TNG: "The Outrageous Okona")
- the Borg (TNG: "Q Who")
- the Lysian Alliance (TNG: "Conundrum")
- the Straleb (TNG: "The Outrageous Okona")
- the Talarians (TNG: "Suddenly Human")
In 2365, the class 9 cargo vessel Erstwhile was armed with a 2.3 megawatt laser array with four emitters. (TNG: "The Outrageous Okona", production art) As of that same year, the Solari of Solais V were utilizing hand-held laser weapons capable of vaporizing a humanoid during their civil war.
Starfleet Regulations called for a Federation starship to go to yellow alert when targeted by laser weapons from another vessel. In 2365, USS Enterprise-D captain Jean-Luc Picard thought the rule was outdated, since the laser weapons of an Atlec vessel were incapable of even penetrating the navigational deflectors. Picard also noted that Atlecs could fire until their lasers ran dry and they still wouldn't have caused any damage to the Enterprise. (TNG: "The Outrageous Okona")
In 2371, as a result of both radiation poisoning and close proximity to an artificial quantum singularity, Chief Miles O'Brien began experiencing jumps through time by approximately five hours. In one of these jumps, he saw himself being killed by what he later thought could have possibly been a high-energy laser. (DS9: "Visionary")