Photonics Dictionary

Sisyphus cooling is a technique used in atomic physics to achieve ultracold temperatures of atoms or molecules by exploiting the periodic motion of particles in optical traps or lattices. The name...

The angle at which photoelectric sensors are aligned to prevent light from being reflected back to the sensor from the object during retroreflective sensing; also, the angle a measured part is...

Any ray through an optical system that is not a meridional ray. The plane created by a refracted skew ray does not contain the optical axis.

A system employing a dark trace tube in which the opacity of the screen is varied as a function of the power of the beam.

Variations in signal detected on a bolometer that are caused by instabilities in the temperature of the sky.

A skyrmion is a topologically stable, vortex-like configuration of spins in a magnetic material. These configurations are characterized by a swirling pattern where the direction of the magnetic...

Solid-state laser geometry in which the standard rod is replaced by a slab of laser material. Often called total-internal-reflection face-pumped laser (TIR-FPL).

A waveguide with a rectangular cross section that is composed entirely of dielectric materials.

The process of making an abrupt break in a spherical surface on a spectacle lens so that a new center of curvature is set for a portion of the lens. This has the effect of adding a prism to that...

A crystal, glass, or quartz slicing and cutting machine is a specialized piece of equipment used in the manufacturing process to precisely cut and slice materials such as crystals, glass, and quartz...

An optical projection device designed to project positive color transparencies onto a screen for viewing.

An aperture, usually rectangular in shape, with a large length-to-width ratio, and a fixed or adjustable shape through which radiation enters or leaves an instrument. The aperture is generally small...

The error inherent in spectral energy or spectrophotometric quantity due to the finite dimension of the entrance and exit slits.

A slot modulator in photonics refers to a type of optical modulator that operates based on the principle of modifying the optical properties of a slot waveguide. A slot modulator is an optical...

The name of the mixture of liquid and grinding or polishing compounds used in processing optical materials.

A bomb guided to its target by some form of electro-optical system.

Smart cities are urban environments that use information and communication technologies (ICT) and data-driven solutions to optimize city operations and services across various domains such as...

An array of active optical devices (modulators, laser diodes and/or detectors), each of whose electrical inputs or outputs are directly connected to electronic logic circuits, which also are a part...

Structural surfaces that incorporate an embedded sensor network capable of detecting flaws within the structure.

A lack of resolution in a television image as a result of smear ghosts or an insufficiently high video-frequency response. The distortion appears to be extended horizontally and blurred.

A false image in television that follows the desired image so closely that it appears to be smeared.

A form of liquid crystal in which flow does not take place in the usual manner. When examined with polarized light, the substance often forms drops that display a series of fine lines. X-ray...

A transmission interference microscope that produces interference patterns of a sample by using birefringent plates that split a polarized beam of light into ordinary and extraordinary rays, then...

The incident ray, the normal to the refracting surface at the point of incidence of the ray at the surface, and the refracted ray all lie in a single plane. The ratio of the sine of the angle between...

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

An instrument used for viewing in low levels of illumination by means of infrared radiation. A high-aperture lens forms an image of distant objects on the photocathode of an infrared-sensitive image...

An electric discharge lamp in which the conducting vapor is that of metallic sodium instead of the usual mercury. It emits a strong yellow light of a single wavelength.

A term describing an antireflection coating that may be applied to optics that cannot tolerate the high temperatures usually required for normal "hard'' coatings. Such coatings lack durability...

Blocking by means of a pitch ring, pitch button or a totally pitched block. Pitch, containing a soft filter, may be used between the optical components to bar lateral movement.

Term applied to radiation composed of particles or photons that will not easily penetrate a material because of their low energy levels.

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.

A group of solar cells that are electrically contacted and physically arranged so that they may be oriented in the direction of the sun simultaneously.

A material, such as gold black and carbon black, that is used as a solar absorber because of its high absorptance and low reflectivity over the solar spectrum.

A device for converting sunlight into electrical energy, consisting of a sandwich of P-type and N-type semiconducting wafers. A photon with sufficient energy striking the cell can dislodge an...

Solar radiation intensity existing in free space at the mean solar distance of the Earth. Commonly expressed in g cal cm-2min-1, the constant is equal to the amount of incident radiation -- in unit...

An optical system that is designed to produce a high temperature in a specified area by the optical direction and concentration of solar radiation on that area. The system usually consists of a...

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.

Measurement of absorption by the gas of interest in the 2- to 6-µm range as a function of tangent height pressure. The pressure profile may be inferred by using CO2 absorption profile...

Radiation from the sun that is made up of a very wide range of wavelengths, from the long infrared to the short ultraviolet with its greatest intensity in the visible green at about 5000 Å. The...

The simulation of solar radiation in the infrared and ultraviolet spectrum for the analysis of extraterrestrial sunlight and its effects on spacecraft, materials and components.