Laser optics essentially means optical elements and systems which are used with lasers – either as parts of lasers or for transmitting and manipulating laser beams or other forms of laser light.
Laser systems use plano-convex lenses to focus laser light. Laser light enters a convex lens and begins to converge to a focal point, upon crossing the focal point, the light then diverges out again.
The laser lenses therefore consist of zinc selenide (ZnSe). This material is heat-resistant up to a temperature of 1,500°C and gives the laser lenses their typical orange colour. In addition, the lenses are coated with a thin layer of thorium fluoride.