Photonics Dictionary: R

Rare-earth elements (REEs) are a group of seventeen chemical elements found in the Earth's crust, characterized by their unique properties and scarcity relative to other elements. Despite their name,...

Plates of glass containing as many heavy metal oxides as can be dissolved in the glass without causing devitrification. The glass is yellow, very heavy and has a high refractive index. It is almost...

The analysis, by x-rays, of the crystalline structure and other properties of metals and alloys.

A metal device of convex or concave curvature to which lens castings or semifinished lenses are cemented with only their edges in contact with the device.

Reactive evaporation refers to a process in thin-film deposition where a material is deposited onto a substrate through evaporation, and chemical reactions take place during or after the evaporation...

The growth of particular grain fragments in a metal or alloy, at the expense of others, that occurs when the metal or alloy is severely worked, as by cold rolling. Recrystallization results in...

Thin-film coating, single or multilayer, that is applied to a substrate to increase its reflectance over a specified range of wavelengths. Metal film, transparent or opaque, is the oldest form of...

Rockwell hardness (Rc) refers to a method for measuring the hardness of a material, primarily metals, using an indentation test. It is named after the Rockwell scale, which was developed by Stanley...