Photonics Dictionary: S

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.

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.

Oscilloscope electronic circuit that produces an output pulse whose pulse width is determined by the time that the output voltage exceeds a specified level.

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...

Bar pattern represented as a sine curve in which the light distribution varies in one direction.

A gelatinous fluid that can be used as a porous thin-film coating for optical components, including laser beam collimators, or as a protective coating for glass and crystalline materials.

The process of transferring collected energy from solar radiation into a heat-absorbing medium (e.g., an insulated tank of water) for use at a later time.

A volumetric electrical charge resulting from a flow of charged particles across a gap.

A mask-alignment microscope used to produce and inspect microcircuits in the electronics industry. It provides flat-field, distortion-free images at all magnifications with a high-intensity vertical...

A sputtering target is a solid material used in the process of physical vapor deposition (PVD), specifically sputtering. Sputtering targets are typically made of metals, metal alloys, or compounds...

In microscopy, a calibrated scale on a slide that may be viewed to determine the exact magnification factor of the microscope.

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

The projection of the image beam by a cathode-ray tube through a mask, where it is deflected through the suitable character position in the mask and then deflected by another system to its suitable...

A rangefinder similar to a pair of binoculars with a long base, a dot or other wander mark provided in each eyepiece field, together forming an apparent point in space. When one dot is moved...

A high-speed network or subnetwork that provides a connection between servers and data storage devices.

Interval between cutting off a photoconductor's signal and the fall of current output to 90 percent.

A cathode-ray tube combined with an electrostatic storage unit that is used to introduce, store and retrieve information translated into electric charge form.

Birefringence of materials that is induced or altered by stress fields.

In a microscope, the optical assembly that focuses light on the specimen and into the objective.

An image of an object that appears above the object's true position as the result of abnormal refraction of the image rays by the atmosphere.

A liquid crystal display using the material in its supertwisted nematic phase; the birefringence of the liquid crystal results in a characteristic yellow or blue color, unless corrected.

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

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

A positive after-image that is maintained for a minute or more.

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...

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

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.

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...

Sapphire crystal refers to a transparent, single-crystal form of aluminum oxide (Al2O3) known as corundum. It is one of the hardest known materials, second only to diamond on the Mohs scale of...

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...

Sapphire refers to a crystalline form of aluminum oxide (Al2O3) that is used in various optical and photonic applications due to its exceptional optical, mechanical, and thermal properties. Sapphire...

A saturable absorber is a type of optical device that exhibits variable absorption properties depending on the intensity of incident light. In essence, it becomes less absorbent as the light...

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...

1. A polariscope consisting of a Savart plate and a tourmaline plate analyzer, and used to produce parallel color fringes by transmitting polarized light. 2. A polariscope composed of an analyzing...

Scalar diffraction theory is a simplified approach used to describe the propagation of electromagnetic waves, particularly light, as they encounter obstacles or apertures. It is termed "scalar"...