Photonics Dictionary: S

The successive analysis or synthesizing of the light values or other similar characteristics of the components of a picture area, following a given method.

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...

A light, radar or electron beam used to scan according to a particular method.

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...

In field-sequential color television, the rotating tricolor disc placed between the subject and the lens, or between the picture tube and the viewer.

The picture formed by the scanning beam of electrons in a scanning electron microscope.

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 device composed of a light source and phototube used to scan a moving strip of material in photoelectric side-register control systems.

1. The continuous thin strip marked by the scanning beam. Generally, during return of the scan, the line is blanked out. 2. The thin strip marked by the scanning process and composed of the...

A microdensitometer that contains a scanning stage to provide simultaneous representations of position vs. density.

A contour mapping technique that uses electronic scanning and sampling techniques instead of a reference grating (see moire topography; projection moire topography) to obtain moire fringes, producing...

See atomic force microscope; magnetic force microscope; near-field scanning optical microscope; scanning tunneling microscope.

A spectroradiometer having a means to scan different regions of the light spectrum, providing simultaneous representations of amplitude vs. wavelength of the spectrum.

The picture area scanned per second.

The spot illuminated on a cathode-ray tube by the initial impact of the scanning ray and the screen.

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...

A nonlinear label-free imaging technique commonly used during surgical procedures for the visualization of collagen fibers and muscle tissue (myosin) with submillimeter resolution. During the...

Second-harmonic generation (SHG) is a nonlinear optical process that occurs when two photons with the same frequency combine within a nonlinear material, resulting in the generation of a new photon...

The process of grinding the convex surface of a convexo-concave meniscus.

A photoconductive cell consisting of a layer of selenium on a substrate whose electrical resistance varies with the illumination falling on the cell. Selenium cells have been replaced largely by...

A formed piece of glass, one surface of which has been ground and polished to the required curvatures.

A term used to describe a spectacle lens or blank with one surface totally finished.

Raster scanning process like that of television: each line is scanned successively.

A closed-loop system that is constantly adjusted in response to input signals generated within the system.

A term that describes an incomplete polish.

A short focal length (less than five inches) positive lens used to produce a magnified image of the object being viewed. While a single element will function, an achromat or multielement assembly...

A high-power riflescope specifically intended for sighting and shooting distant targets.

Gas detection measurement technique that uses a built-in capacitative microphone to calculate the amount of absorbed laser power in a gas cell according to variations of gas pressure.

A scanning process in which the greatest amount of radiation determines part of a spiral motion rotating in one direction.

When splitting the output of a single optical fiber into two or more fibers, the difference in the maximum loss between any two channels.

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

An approach to character recognition based on the structure of the character to be identified (number of straight lines, bays, holes, etc.); used where simple matching is not viable, as in...

A copolymer of styrene and acrylic used in molded optical components; it has a high refractive index and a low coefficient of thermal expansion.

(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.

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

The reversal of a developed image due to the exposure of the partially developed image to actinic light.

The movement of the eye as it focuses on details of a scene. Some imaging systems mimic this movement by small, rapid scanning motions of the sensor.

1. In the geometric sense, an abbreviation for the term "sagitta,'' the height of a curve measured from the chord. and it is exact for a parabola. 2. Conforming a sheet of glass to a...

Sagnac interferometry is a technique used to measure rotation or angular velocity based on the principle of interference. It relies on the Sagnac effect, named after the French physicist Georges...

The simultaneous exposure of two holographic plates with emulsions facing the object. After deformation, a second pair of plates is exposed to the deformed object. The back plate of the initial pair...