Fictional weapons come in all types and sizes. But I will talk about Photon based weapons. To understand it, one must understand Photons: Photons are condensed light energy which contains mass when focused.

This is not something you want in personal firearms. Because, it takes more energy to fire this energy based weapon. However! The damage it produce in large quantities might be enough. Science Fiction uses them in heavy weaponry like an explosive rocket or torpedo.

These are my ideas for photon energy based tools and weaponry:

1. Flash bombs and grenades. Blinding opponents is not a new idea. But since photons are a principal part of flash grenades, the radius can be turned up a lot. The more energy stored, the bigger the flash.

Large rooms filled with blinding light from a larger grenade is scary. Is it one person or many? It is a good tool. However this is not enough.

2. Explosive plasma grenades. Instead of using photon grenades, the damage of hot, searing of plasma will work. After all it is a hotter physical state than gas. Think of it as something that can burn into steel.

3. Using photons to create a force to push something. This is an idea similar to shielding. It can be turned into weaponry. How? Environmental hazards anyone? 

4. If you are using photon weapons, make sure to make it big. After all, massive amounts of energy release ends up a concussive boom. And the human body can take so much pressure before it dies.