Below is a list of Solid State Laser manufacturers from St. Louis, Missouri. Solid state lasers are laser systems that generate laser beams through the use of a solid gain medium. A gain medium is the source of light and mechanism of light amplification within all laser equipment. Solid gain media are often composite crystals doped with rare-earth ions like neodymium, ytterbium and erbium.Lasers are used in a variety of contexts spanning across industry and commerce.