Diferença entre um blaster, fóton e phaser?

TL; DR:

• Os Phasers de Star Trek são basicamente armas energéticas coerentes, semelhantes aos lasers.

• Os blasters de Star Wars eram uma forma evoluída de armas de laser e disparavam um "parafuso" coerente de partículas de energia, em vez de um raio de luz total.

De Wiki em Star Trek Phaser:

Originally (from the production notes to TOS), the Phaser was a PHoton mASER, since at the time of writing the Laser was a relative unknown, and powers were not expected to be very great. Masers, on the other hand, were already very powerful machines which produce very destructive radiation pulses. The term "phaser" has since been revised as a backronym for PHASed Energy Rectification, though from a physics standpoint even this is of equal semantic content—ordinary incoherent light is not "rectified", or synchronous, whereas Lasing and Masing emissions are rectified, or synchronous. Phasers release a beam of fictional subatomic particles called "rapid nadions", which are then refracted ('rectified') through superconducting crystals. Given the nature of photons the first acronym seems more accurate. The Star Trek: The Next Generation Technical Manual indicates that the superconducting crystals used in phasers are called fushigi no umi. This was an homage to the 1990 anime series Fushigi no Umi no Nadia, known in North America as Nadia: The Secret of Blue Water. The phasers that appeared in the 2009 reboot Star Trek appear similar to classic phasers, but fire 'bolts' of energy instead of sustained beams, and seem to only have two settings, stun and kill.

Do Wiki no blaster de Star Wars :

In the story line of the movie, common blaster weapons were said to use high-energy gas as ammunition; activated by a power cell and converted into plasma. The plasma was then released from a magnetic bottle effect to fire through collimating components as a coherent energy bolt. Inherent instabilities were said limit the ability to precisely aim a blaster bolt, but knowing one's weapon well could strengthen marksmanship. Plasma energy was said to be dissipated as the bolt traveled, limiting range as the energy became incoherent. The science fiction further described that longer range was achieved by using longer collimating tubes, to align the plasma energy carrier waves more closely through additional galvan circuitry.

Um "phaser" de acordo com a maioria das fontes in-canon é basicamente um poderoso laser polarizado. Na reinicialização, os efeitos visuais mudaram de tal forma que os phasers não mais disparam feixes, mas "pacotes" de energia de fótons.

Uma "arma de fótons", em geral, é qualquer arma que dispara um fluxo direto de fótons.

Um "blaster" é uma arma que dispara não luz, mas uma carga de plasma autônoma. Os parafusos Blaster, ao contrário dos feixes de phasers, viajam em velocidades sublight.