Definitions

Also known as Fresnel reflection. That portion of the incident radiation that is reflected from the surface of a refractive material. It is a function of the refractive index of the material. At...

A wave that is guided by the interface between two different media or by a refractive index gradient in the medium. The field components of the wave may exist (in principle) throughout space, even to...

A semiconductor laser diode that emits light perpendicular to the active region. The output radiation is taken through the surface as opposed to through a cleaved mirror.

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

Surface-enhanced Raman scattering (SERS) is a powerful analytical technique that enhances the Raman scattering signal of molecules adsorbed on or near certain nanostructured surfaces. Raman...

Surface-enhanced Raman spectroscopy (SERS) is an analytical technique that combines the principles of Raman spectroscopy with the enhancement provided by nanostructured metallic surfaces. Raman...

A surface-mount device (SMD) is an electronic component that is mounted directly onto the surface of a printed circuit board (PCB) rather than being inserted into holes drilled in the board (as with...

The material removed during diamond machining of glass components.

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...

Thermal interface materials (TIMs) are substances or compounds used to enhance the thermal conductivity between two surfaces in contact. These materials are primarily employed in electronic devices,...

Multiple exposures of holograms, one for each position of a vibrating image, that are used for vibration analysis and that yield a record of the time-averaged irradiance distribution at the hologram...

A surface that is swept out by revolving a circle about an axis that lies in the plane of the circle but that does not intersect its center. The result is a surface having different curvatures in...

The method used to measure the index profile of an optical fiber by placing it in an interferometer and illuminating the fiber transversely to its axis.

A testing device that provides a contour map of the emergent wavefront for the observer in terms of the given wavelength of the light.

Twyman-Green interferometry is a technique used in optics to measure the flatness or surface profile of optical components with high precision. It is based on the principles of interference of light...

In interferometry, the result of superimposing two wavefronts of identical shape, yielding a uniform intensity interference pattern with no bands.

A phase-shift interferometer used to detect the relative angular speeds or positions of two concentric rotors.

A laser that has a surface-emitting semiconductor gain element coupled to an external mirror designed to complete the laser resonator. VECSELs can be electrically or optically pumped. The extended...

Consists of a pair of radio telescopes concentrated on a single celestial object. This technique creates a single radio telescope with a diameter equal to the distance between the pair, which allows...

The method by which Thomas Young in 1802 disproved Newton's corpuscular theory of light by the formation of interference patterns between two beams of light from the same source. This was produced by...

A glass substrate that has its rear surface coated with a reflective coating. Also known as a back-surface mirror.

A dichroic mirror, also known as a dichroic beamsplitter or interference filter beamsplitter, is an optical device that selectively reflects or transmits light based on its wavelength. Dichroic...

The diffraction pattern of a source such as a light-emitting diode, injection laser diode or the output end of an optical waveguide observed at an infinite distance from the source.

A region far from an aperture or source where the diffraction pattern is essentially the same as that at infinity. Changes in diffraction patterns of points within the far-field region are...

A laser rangefinder is a device that uses laser technology to measure the distance between the device and a target. It operates on the principle of measuring the time it takes for a laser beam to...

Magnetorheological finishing (MRF) is a precision optics polishing technique used for shaping and finishing optical surfaces to achieve extremely high levels of smoothness and accuracy. It is...

Meta-optics, also known as metasurface optics or flat optics, is a branch of optics that involves the design, fabrication, and utilization of artificial structures called metasurfaces to control and...

A metalens, short for "metasurface lens," is a type of optical lens that uses nanostructured materials to manipulate light at a subwavelength scale. Unlike traditional lenses made of glass or other...

A lithography method that allows the transfer of fine-pitch gratings from a phase mask into photoresist. The exposure takes place with the light coming under an oblique angle to the mask. The...

The area closest to an aperture or source where the diffraction pattern differs substantially from that observed at an infinite distance, or more specifically, the far field. Also referred to as the...

A scanning probe microscope that analyzes the surface of a specimen by recording the intensity of light as it is focused through a pipette and raster scanned across the specimen at a distance less...

A measurement technique used to determine the spatial distribution profile of an electrical or optical quantity of interest which is provided by multiple scans within the near-field region of a...

In a laser diode, lateral motion of the beam center at the facet when the drive current is changed.

Number of pulses emitted per unit of time by a pulsed laser.

The frequency range for radio and television transmission.

A gas laser in which the electrodes are mounted perpendicular to the optical resonator.

A very uncommon lamp in which a tungsten electrode is heated to incandescence by a radio-frequency electrical current.

A device used to accelerate the electrons in a free-electron laser by channeling microwave energy into waveguide cavity assemblies.

1. An optical distance finder that depends on triangulation of two convergent beams on an object from disparate view points. 2. A device that depends on the measurement of time of wave travel from an...

Ratio between map or photo linear distance and the actual ground dimensions represented.