Lasers are a mysterious technology. Nobody really knows exactly how to create them. However using some prismarine both dark and light, one is able to create an Aquatic Catalyst.
While this block itself does not possesses the ability to channel energy into a laser. It can be accomplished by supplying the catalyst with fuel, like for example Kelp and activating it with a Heart Of the Sea.
After right-clicking the item on the catalyst, a laser beam will shoot out of the opposite side as long as it has a target.
By shooting a laser beam into a crystal, one can increase the lasers purity. The lasers that are created by this shot (top and bottom) now have a purity of 3.0 this means they can be used for Item Transformation!
Next: Item Transformation