Optical materials

Sapphire is a gemstone variety of the mineral corundum, an aluminium oxide (α-Al2O3).

Potassium bromide (KBr) is a salt, widely used as an anticonvulsant and a sedative in the late 19th and early 20th centuries, with over-the-counter use extending to 1975 in the US.

Poly(methyl methacrylate) (PMMA), also known as acrylic or acrylic glass as well as by the trade names Plexiglas, Acrylite, Lucite, and Perspex among several others (see below), is a transparent thermoplastic often used in sheet form as a lightweight or shatter-resistant alternative to glass.

Calcite is a carbonate mineral and the most stable polymorph of calcium carbonate (CaCO3).

Zinc selenide (ZnSe) is a light-yellow, solid compound comprising zinc (Zn) and selenium (Se).

Zinc sulfide (or zinc sulphide) is an inorganic compound with the chemical formula of ZnS.

Lithium fluoride is an inorganic compound with the chemical formula LiF.

Magnesium fluoride is an inorganic compound with the formula MgF2.

Arsenic triselenide (As2Se3) is an inorganic chemical compound, a selenide of arsenic.

Calcium fluoride is the inorganic compound with the formula CaF2.

Barium fluoride (BaF2) is a chemical compound of barium and fluorine and is a salt.

Germanium dioxide, also called germanium oxide and germania, is an inorganic compound with the chemical formula GeO2.

Cadmium selenide is an inorganic compound with the formula CdSe.

Strontium fluoride, SrF2, also called strontium difluoride and strontium(II) fluoride, is a fluoride of strontium.

Gallium phosphide (GaP), a phosphide of gallium, is a compound semiconductor material with an indirect band gap of 2.

Arsenic trisulfide is the inorganic compound with the formula As2S3.

Tellurium dioxide (TeO2) is a solid oxide of tellurium.

Magnesium oxide (MgO), or magnesia, is a white hygroscopic solid mineral that occurs naturally as periclase and is a source of magnesium (see also oxide).

Yogo sapphires are a variety of corundum found only in Yogo Gulch, part of the Little Belt Mountains in Judith Basin County, Montana, United States, on land once inhabited by the Piegan Blackfeet people.

Picarin is a plastic used to make optics such as lenses for terahertz radiation (THz radiation).

In the field of optics, transparency (also called pellucidity or diaphaneity) is the physical property of allowing light to pass through the material without being scattered.

Yttrium aluminium garnet (YAG, Y3Al5O12) is a synthetic crystalline material of the garnet group.

Lithium niobate (LiNbO3) is a compound of niobium, lithium, and oxygen.

Caesium cadmium chloride (CsCdCl3) is a synthetic crystalline material.