Photonics Dictionary: S

A solid-state laser is a type of laser that uses a solid gain medium (as opposed to a liquid or gas) to produce coherent light. The term "solid-state" refers to the fact that the active medium, where...

The luminescence of a substance resulting from its exposure to ultrasonic waves.

The diagnostic procedure that uses ultrasonic energy to probe the body and, with the help of laser beams, a reflecting membrane to produce a three-dimensional picture.

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

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,...

A spatial light modulator (SLM) is an optical device that modulates or manipulates the amplitude, phase, or polarization of light in two dimensions, typically in the form of an array. SLMs are...

The change in position of the image of a sine wave object from its ideal position. Usually measured in degrees with 360° designating a full cycle of the image.

Spatial resolution refers to the level of detail or granularity in an image or a spatial dataset. It is a measure of the smallest discernible or resolvable features in the spatial domain, typically...

The correlation of radiation between the phases of monochromatic radiation emanating from two separate points.

Spatially offset Raman spectroscopy (SORS) is a technique that extends traditional Raman spectroscopy by incorporating measurements at different spatial offsets. This method allows for the selective...

Of evaporative coatings, a condition resulting when small chunks of material fly from the hot crucible onto the substrate surface and adhere there.

In laser systems, the granular effect that is noted when observing the expanded cross section of a laser beam.

Average wavelength usually determined for light-transmitting devices by taking a weighted average for each wavelength of the spectral energy distribution of incident light, transmittance of the...

Spectral domain optical coherence tomography is an imaging technique used in medical diagnostics, particularly in ophthalmology, to visualize and analyze the internal structures of biological...

Spectral flow cytometry is an advanced flow cytometry technique that expands the capabilities of traditional flow cytometry by utilizing spectral information from fluorochromes to enhance...

Spectral repeatability refers to the consistency and reproducibility of spectral measurements across multiple trials or instances. It is a measure of how well a measurement instrument or system can...

A spectral signature, in the context of remote sensing and spectroscopy, refers to the unique pattern or characteristic spectral response of a material or object across different wavelengths of the...

An automatic scanning instrument that is used to study a substance's fluorescence over a wide range of wavelengths. It consists of a radiation source, a grating that functions as the monochromator in...

An optical instrument for forming the spectrum of a light source and recording it on a film. The dispersing medium may be a prism or a diffraction grating. A concave grating requires no other means...

An instrument similar to the spectroheliograph, but having a scanning method that is performed by a pair of rapidly oscillating slits or a rotating glass block located before a pair of fixed slits at...

An analytical technique used to determine, identify and localize impending malfunctions. It is based upon quantitative and qualitative measurement of submicroscopic particles suspended in lubricating...

An instrument for plotting the rotatory dispersion of a substance at different wavelengths.

A spectroradiometer is a device used to measure the intensity of light at different wavelengths across the electromagnetic spectrum. It provides a detailed spectral distribution of light, breaking...

Spectroscopy is a technique used in the study of interactions between matter and electromagnetic radiation. It involves measuring and analyzing how different materials absorb, emit, or scatter light,...

A sensitometer having a continuously controlled monochromator to measure spectral sensitivity and contrast of photographic materials.

A spheric lens, also known as a spherical lens, is a type of optical lens with at least one surface that is part of a sphere. This means that the lens surface is curved in a symmetrical manner,...

Spherical aberration is an optical aberration that occurs when light rays passing through a lens or curved optical surface do not converge or diverge to a single focal point. Instead of focusing to a...

In gradient index optics, a gradient profile in which the refractive index varies symmetrically about a point.

A tiny lens (as small as 100 µm in diameter) used to focus light on charge-coupled devices, formed by heating a photosensitive material exposed through a mask, leaving a pattern of raised...

An instrument for measuring the radius of curvature of a spherical lens or mirror surface. It may consist of a ring resting on the surface, with a micrometer plunger in the middle of the ring to...

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

Potential alternative to the conventional pulse approximation method of digital image processing because of its highly desirable interpolating and approximating characteristics.

A lens derived from the Cooke triplet anastigmat, but with one of the crown elements split in two, resulting in improved speed and correction of aberrations.

A method of evaluating image quality whereby a large number of rays are traced through a lens from a single object point, and their intersections with the focal plane are plotted and analyzed.

A telescopic light-sensing meter used to measure illumination levels of small regions at a distance of many feet; it is used in professional motion picture and television production to ensure proper...

A vacuum deposition method in which the coating material (target) is removed from the surface of the coating source (cathode) by ion bombardment and deposited upon the substrates.

Sputtering equipment is machinery used in the process of physical vapor deposition (PVD), specifically sputtering. Sputtering is a method of depositing thin films of material onto a substrate surface...

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...

A laser resonator in which a mode oscillating between the mirrors will converge upon the laser's longitudinal axis.

A type of laser used when a great amount of power is required. Avoiding the bulk of large numbers of optical lenses, this instrument offers high-output intensity and a small emitting region at...

A reticle pattern in a surveying instrument consisting of parallel lines that can be superimposed on a calibrated rod, making possible determination of the distance from the instrument to the rod.

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

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...

A technique for creating optimal performance in a system by producing a specific beam irradiance distribution, usually through the use of geometric optics. A common design involves the use of ray...