Photonics Dictionary: A

An Abbe-Porro prism, often referred to simply as a Porro prism, is an optical prism used in binoculars and other optical instruments to invert and reverse an image. It is named after the Italian...

Absorptance refers to the fraction of incident electromagnetic radiation (such as light or infrared radiation) that is absorbed by a surface, rather than being reflected or transmitted. It is a...

Achirality refers to the property of a molecule or object that is superimposable on its mirror image. In other words, an achiral molecule or object does not exhibit chirality, meaning it does not...

An active infrared (IR) system is a type of technology that uses infrared radiation actively emitted and detected by sensors for various purposes. Here are the key features and applications of active...

An instrument that reads alphabetic, numerical and special characters by means of a photosensor that measures the varying intensity of the characters reflected from a light source.

The angle through which a ray of light is deviated by a refracting or reflecting surface, or a prism; the angle between an incident ray and the refracted or reflected ray.

An antireflection coating (AR coating) is a thin film or coating applied to optical surfaces, such as lenses or windows, to minimize unwanted reflections and increase the transmission of light...

An autocollimator is an optical instrument used for measuring small angular deviations with high precision. It operates on the principle of autocollimation, where a light source is directed onto a...

1. In astronomy, the angle measured clockwise (eastward) in a horizontal plane, usually from north (true north, Y-north, grid north or magnetic north). 2. With relation to the plane-polarized light...