Stereolithography (SLA or SL) also known as vat photopolymerisation,optical fabrication, photo-solidification, or resin printing) is a form of 3D printing technology used for creating models, prototypes, patterns, and production parts in a layer by layer fashion using photochemical processes by which light causes chemical monomers and oligomers to cross-link together to form polymers. Those polymers then make up the body of a three-dimensional solid. Research in the area had been conducted during the 1970s, but the term was coined by Chuck Hull in 1984 when he applied for a patent on the process, which was granted in 1986. Stereolithography can be used to create prototypes for products in development, medical models, and computer hardware, as well as in many other applications. While stereolithography is fast and can produce almost any design, it can be expensive.
The three technologies all use a light source to cure a photopolymer resin but with the following differences:
Stereolithography (SLA) uses UV lasers as a light source to selectively cure a polymer resin.
Digital light processing (DLP) uses a digital projector as a UV light source to cure a layer of resin.
Liquid crystal display (LCD) uses an LCD display module for projecting specific light patterns.