The Star Trek: The Original Series type 1 phaser.
It was named as the "type 1 phaser" in the first season episode, "The Devil in the Dark".
The name "phaser" came from Gene Roddenberry. Two days into filming the pilot, "The Cage", Roddenberry realized that fans would not believe that a laser could do all the things the show wanted it to do. Roddenberry had learned of "phasing" energy to higher wavelengths (a concept only recently discovered in the early 1960s), and so came up with the name "phaser".
The prop was designed by Matt Jefferies and John Jefferies with input from Gene Roddenberry. John Jeffries drew five different designs, none of which Roddenberry liked. Elements of all five were combined to come up with a phaser Roddenberry approved of. The final design was inspired by a television remote control recently offered for sale by Magnavox!!
Construction occurred in the Desilu prop shop, although it is unclear if Matt Jefferies personally built it or merely supervised its construction. Initially, the phaser was colored black and white. Roddenberry did not like how these looked on film, and asked propmaster Wah Chang to repaint them dark grey and add some details.
The first type I phaser was a pistol-like device of blue-gray with a black grip. An adjustment dial existed on the left side near the front, and another toward the top at the rear. The rear also featured radiator cooling fins, and a small metal button on the left side for releasing the power pack. The power pack fitted into the top of the phaser pistol grip, and was colored black. It had a screen on top that initially was supposed to provide cooling. A white ribbed dial and a meter of clear, curved plastic to its left were just behind the screen. The power back sat in a cut-out on the pistol, with slight flaring below it.
The original sound of phaser fire was a sped-up version of the "hovering sound" of the Martian fighting machine heard in the 1953 film War of the Worlds. The sound of feedback from an electric guitar and from a harp were blended into the hover to create the phaser sound.
Gene Roddenberry disliked the design of the type I phaser pistol because it looked too much like a gun. Roddenberry, who believed firmly that people in the future would have "moved beyond conflict" wanted the phase redesigned.
A complete redesign was not possible. So Matt Jeffries merely took the power pack off the pistol and used the power pack alone as the "jewel phaser". (This term is used by fans, not in the series.)
Slight modifications of the "jewel phaser" were made. What appeared to be a cooling screen was really a pop-up sight, with a translucent curved screen attached to it that had aiming marks on it. The anonymous flush button behind the screen, visible in the pistol version, was now the firing pin.
A small clear plastic nodule was added to the front, as the point where "the phaser comes out".
As Roddenberry's involvement with Star Trek: The Original Series declined over the series' run, the show returned to the use of the phaser pistol. Thus, Roddenberry's wish that the "jewel phaser" be used exclusively was never really honored.
Shot of a good replica of the "jewel phaser".