Photonics Dictionary: S

A type of interferometer in which two coils of optical fiber are arranged so that light from a single source travels clockwise in one, and counterclockwise in the other. Rotation of the coils causes...

An interferometer in which interference is produced between wavefronts that are sheared in the sample object by a small lateral distance.

The method for measuring the index profile of an optical fiber by preparing a thin sample that has its faces perpendicular to the axis of the fiber, and measuring its index profile by interferometry.

Spatial light interference microscopy (SLIM) is an optical microscopy technique that belongs to the category of quantitative phase imaging methods. It is designed to provide high-resolution,...

The interference of the two real images formed by a Billet split lens.

An instrument that divides a single laser beam in two and uses one half as a sensing beam and the other as a reference beam, then recombines the two and measures any phase shift between them. The...

A plane-parallel interferometer that yields extremely high contrast over a wide range of finesse values without significantly reducing transmission.

A pulsed interferometer that permits the continuous quantitative mapping of the surface deformation of an adaptive optical element (e.g., a deformable mirror) and provides the capability for...

The process in which the normal rate of fluorescent emission from a substance is enhanced by virtue of the optical gain of the medium; i.e., energy is lost not only by spontaneous emission but also...

1. In optics, one of the exterior faces of an optical element. 2. The process of grinding or generating the face of an optical element.

An acoustic wave that propagates along the surface of a solid and decays exponentially with substrate depth. Also called a Rayleigh wave, it has both longitudinal and transverse (shear) components....

(SALI) A type of spectroscopy in which neutral atoms or molecules are ionized by an excimer laser beam and then measured by a time-of-flight mass spectrometer.

Waves that propagate along the interface between two different media without radiation with exponentially decaying evanescent fields on both sides.

The departure of an optical surface from its required tolerance or figure.

A large table with an accurately designed plane surface used to test other surfaces, or to provide a true surface for accurately locating a testing fixture. Most commonly made of granite.

A representation of the shape of a surface, including any roughness or other irregularities. The profile can be generated by direct measurements, as by a stylus, or by remote measurement, as by an...

The specification of allowable flaws in a surface by comparison to reference standards of quality. Two graded sets of surface quality standards are employed. The first denotes defects of a long...

The standards of MIL-O-13830 set by the US government relative to tolerable surface scratches and other such defects in an optical system. A series of standard glass plates that have been...

Also known as Fresnel reflection. That portion of the incident radiation that is reflected from the surface of a refractive material. It is a function of the refractive index of the material. At...

A wave that is guided by the interface between two different media or by a refractive index gradient in the medium. The field components of the wave may exist (in principle) throughout space, even to...

A semiconductor laser diode that emits light perpendicular to the active region. The output radiation is taken through the surface as opposed to through a cleaved mirror.

A technique of optical storage whereby information is encoded by molecular alterations in the interaction between the optical layer and the substrate.

Surface-enhanced Raman scattering (SERS) is a powerful analytical technique that enhances the Raman scattering signal of molecules adsorbed on or near certain nanostructured surfaces. Raman...

Surface-enhanced Raman spectroscopy (SERS) is an analytical technique that combines the principles of Raman spectroscopy with the enhancement provided by nanostructured metallic surfaces. Raman...

The material removed during diamond machining of glass components.

An imaging technique in which an object moving through an interference field formed in space scatters light and is spatially recorded on a photographic film as a hologram. If the interference field...

A surface-mount device (SMD) is an electronic component that is mounted directly onto the surface of a printed circuit board (PCB) rather than being inserted into holes drilled in the board (as with...

A term used to describe a saddle-shaped -- i.e., convex along one axis, concave along the other -- polished surface, generally an error, whose contours are apparent by the shape of Newton's rings.

The shape of the edge of a concave surface when the depth of the bevel plane to the vertex of the surface is controlled to a required distance.

A crude area on the polished surface, produced during coarse grinding, that subsequent fine grinding does not remove, owing, to some extent, to coarse grains of grinding sand that mixed with finer...

Sapphire optical fiber is a type of optical fiber made from single-crystal sapphire, which is a form of aluminum oxide (Al2O3) that is highly transparent in the infrared region of the electromagnetic...

A sapphire window refers to a transparent optical component made from sapphire crystal. Sapphire is a single-crystal form of aluminum oxide (Al2O3) that is highly prized for its exceptional optical...

A double-plate device used to transmit polarized light and form interference fringes of the light, thus indicating its presence. It consists of two calcite plates of equal thickness, cut parallel to...

Also called scanning laser acoustic microscope. A device that uses high-frequency ultrasound waves to penetrate surfaces. A scanning laser beam is used as a detector, which transmits information...

Measures by heterodyning interferometry the local slope of a vibrating sample. The method allows the reconstruction of a three dimensional map of the surface in order to determine the slope and...

A scanning electron microscope (SEM) is a powerful imaging instrument used in scientific research, materials characterization, and various industrial applications. Unlike traditional optical...

Scanning electron microscopy (SEM) is an advanced imaging technique used in microscopy to obtain high-resolution, three-dimensional images of the surfaces of solid specimens. SEM achieves this by...

A high-resolution imaging instrument that can detect and measure the positions of individual atoms on the surface of a material. A very fine conductive probe is placed at a distance of 10 to 20...

Measure of the interference fringe pattern produced by the forward scattering of light by an optical fiber; the fringe pattern is inversely proportional to the fiber diameter.

A specific type of filter designed to reduce the amount of light scattered by reflections from the edges of optical components or mounts, or from irregularities on the optical surfaces.

Change of the spatial distribution of a beam of radiation when it interacts with a surface or a heterogeneous medium, in which process there is no change of wavelength of the radiation.

An instrument used to determine the absolute or relative scatter levels of optical surfaces.

A measurement technique used for the rapid quantitative evaluation of surface quality based on the detection and analysis of light scattered from the surface.