Photonics Dictionary: S

Selective laser melting (SLM) is an additive manufacturing (AM) or 3D printing technology that belongs to the powder bed fusion category. SLM is primarily used for metal additive manufacturing, where...

Frequently used in astronomical measurement, it is based on the diurnal rotation of a star relative to the fixed stellar system.

A combination spectrometer and bolometer that is designed to measure a narrow band of radiation from a star.

Two stars so close together that they cannot be resolved by telescopes. They are proved to be double stars by the doubling of their spectral lines.

A passive coupler that distributes signals from one or several inputs among a larger number of output waveguides arranged schematically as a star configuration.

The visual examination by a trained observer of the image of a point source. Any coloring or departure from the Airy disc rings indicates the presence of aberrations in the lens forming that image.

In local area networking, arrangement of the satellite nodes around a central node through which all routing of network data takes place.

Spectrum broadening that results from the influence of an electric field.

The splitting or shifting of spectral lines or energy levels caused by the application of a strong transverse electrical field. It often is studied with a canal-ray tube that has a third electrode...

In a laser, the voltage necessary to initiate electrical discharge, somewhat higher than that needed to sustain it.

The angle subtended by the mean distance of the Earth from the sun at the distance of a given star from the sun.

A substrate refers to a material or surface upon which another material or process is applied or deposited. In various fields, such as electronics, biology, chemistry, and manufacturing, the term...

In a laser, the voltage necessary to sustain a constant operating current, somewhat less than that needed for start-up.