In its report, NASA focused on two different laser technologies—photon pressure and ablation—to help manage space junk.
Photons are massless, elementary particles carrying a small amount of momentum which it transfers to the debris while bouncing off it. This generates thrust which pushes debris away.
The ablation method will use a more powerful laser to "ablate," or erode space debris. This will not contribute any new debris to the space as it only ejects a combination of hot gas and plasma.
The sweeper spacecraft will reduce the amount of space junk by capturing them, slowing them down, or breaking them apart. These sweepers will be large shields orbiting in space.