Photonics Dictionary

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...

Also known as transverse mode. The configurations of energy storage, relative to the structure of a laser resonator, that define the relative intensity distribution of the laser beam.

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...

Spatio-temporal optical coherence tomography (ST-OCT) is an advanced imaging technique that combines the principles of optical coherence tomography (OCT) with spatio-temporal modulation methods to...

The ratio of Young's modulus to density of a material.

A technique for obtaining improved resolution of images produced by large telescopes and distorted by the effects of atmospheric turbulence. Many individual exposures are recorded at high speeds by a...

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...

With respect to color photography, the measurement, at a given wavelength, of the way the color film modulates the radiant flux in the optical system containing the film.

When, for example, a beam of monochromatic light passes through a diffraction grating, the emergent rays that have remained undeviated are included in the zero spectral order. The light flux in the...

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...

Spectra can be conveniently recorded on photographic film or plates. The portions that are occupied by regions of the recorded developed images on the film or plate can be determined with some...

The slits in a spectrograph that form images of spectral lines. Slits may be bilateral or unilateral, and generally close down to 0.01 mm and open up to almost a whole millimeter. The edges of the...

An instrument in which an image of the sun is scanned by the entrance slit of a monochromator, the exit slit simultaneously scanning a photographic plate for analysis of the solar spectral lines. If...

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 spectrophotometer is a scientific instrument used to measure the intensity of light at various wavelengths in the electromagnetic spectrum, typically in the visible and ultraviolet regions. It is...

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,...

A feature in the chromosphere of the sun formed by a jet of gas that reaches from the chromosphere into the corona and has the appearance of a brightly luminous spike.

Acronym for self-aligned polysilicon interconnect N-channel. A metal-gate process that uses aluminum for the metal-oxide semiconductor (MOS) gate electrode as well as for signal and power supply...

Spin coating is a widely used technique in the fabrication of thin films and coatings, particularly in microelectronics, optoelectronics, and nanotechnology. It involves depositing a liquid precursor...

Reciprocal magnetic interaction between nuclei in a molecular system facilitated by the binding electrons of the molecule.

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

A permanent joint whose purpose is to couple optical power among two or more ports. Also, a device whose purpose is to couple optical power between a waveguide and a source or detector.

A close-up lens, semicircular in shape, that is mounted in front of a conventional lens focused at infinity. The result is an image made up of two sections; one focused through the split lens on near...

A passive fiber optic coupler that divides light from a single fiber into two or more fiber channels.

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

The probability that an atom in one state will move spontaneously to a lower state within a given unit of time.

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 platform mount used to hold sensitive optical instruments immobile.

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

The superimposing of holographic pages in a thick, erasable storage material by changing the reference and object beams. This extends the capacity of holographic memories.

A memory system composed of a stack of holographic plates, a mode-locked laser and a rapid detector array. Ultrashort laser pulses are used to extract information from the stack. In this way, storage...

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 lens whose focal length is roughly equal to the diagonal of the negative format of the camera on which it is mounted.