‘Photopolymerization’ is a process of curing photopolymers by light energy.
When a resin is exposed to a particular wavelength of light, the molecules of the photopolymer bond and harden to form a solid.  
Short curing time makes high operation efficiency, and it can be applied to various materials, so it has a wide range of applications.
It is usually used in various fields such as dentistry, 3D printing, industry and beauty.