Plasma phaser
The plasma phaser was a proposed Starfleet weapon for use against the Borg. 

The plasma phaser was still on the drawing board in late 2366. It was projected that this, and other weapons designed to defend against the Borg, would take eighteen to twenty-four months to be ready. 

While preparing to face an imminent Borg invasion in that year, Lieutenant Commander Shelby attempted to suggest modifying the plasma phaser design to adapt it to the existing technologies aboard the . She was stopped by Commander William T. Riker, who ended discussion for that night. ()

See also
Ferengi hand phaser

de:Plasmaphaser
bg:Плазмен фазер
Directed energy weapons