Phased laser

Background
Since the formation of the UFP, the Starfleet was using beam weapons. They used mainly the Phased Cannons and High Densidity Particle Beams (based over Vulcan and Andorian designs). The Phased Cannons not use much energy, but lacks of a good firepower, and the Particle Beams can cause much more damage, but need more energy to fire and refire more slow. So the StarFleet was in a big disadvantage compared which the Klingons, because the Klingon Disrupters have a similar firepower of Particle Beams which a very good refire rate and not need much energy to fire.

Deloping a new beam weapon
So Starfleet was needing a new weapon beam since the relations between both power begin to degenerate at 2218. In the Starfleet was two points of view to work. One was developing a UFP version of Disrupters, but was reject mainly because the Disrupters are too warlike weapons (only can disintegrate, can't set in a stunt fire or graduate the fire power). The other point of view was developing a new beam weapon based over phasing beams, similar to the old Phased Cannon, but which more firepower and better energy performance. In the next ten years, around 2228, the Starfleet Engineers Corps developed a working prototype of Phased Laser. But the early prototypes was a big problem. They auto disintegrate their resonant chamber after a bit fires of the prototypes. This problem not was fixed to around of 2235, when the first truly functional Laser Phasers was equipped to field testing in the USS Yorktown of the Legend class.

How Works
They used the same principles that the Phased Cannons, but instead of using a independent laser for creating the light beam to be phased, the Engineers Corps, make the phaser chamber inside of the resonant chamber of a laser, creating a "phased laser". This increase the weapon damage in a 30% (similar to their time Disrupters and Particle Beams weapons) using the same input energy and making a more compact weapon.

Other names
Some times was called "lasers", sometimes creating a bit of confusion which the Light Amplification by the Stimulated Emission of Radiation or LASER that not is a true weapon. It's was very common calling it like "lasers" in 2250s and 2260s