Photonics Dictionary

Holographic recording whereby the object is illuminated by two pulses, separated by a time interval, from a Q-switched laser source. Each pulse is divided into reference and object beams, and...

An edge-emitting light-emitting diode is a type of LED structure where light emission occurs primarily along the edge of the semiconductor chip rather than from the surface. Edge-emitting LEDs are...

A weight reducing method whereby material from the rear of a reflector is removed leaving a pattern of ribs normal to the surface in an egg-crate pattern.

The spectroscopic analysis of interference patterns using an electronic imaging tube with a Fabry-Perot interferometer to record the fringes.

An electro-optic modulator (EOM) is a device used to modulate the amplitude, phase, or polarization of light waves using an external electrical signal. Electro-optic modulation is a fundamental...

The deflection of a beam of electrons, at regular intervals, across a cathode-ray tube screen, according to a definite pattern.

A method for detecting vibration amplitudes analogous to image holography, except that the film emulsion is replaced by a television target.

An electron-beam lithography (EBL) system is a sophisticated nanofabrication tool used in the semiconductor industry and research laboratories to pattern extremely fine features with sub-micrometer...

An electron-gun system is an assembly used to generate and control a focused beam of electrons. Electron guns find applications in various fields, including cathode ray tubes (CRTs), electron...

The recording of patterns by the production and use of latent electrostatic charge patterns. See electrostatic process.

An emission spectrum is a graphical representation or a characteristic pattern of the wavelengths or frequencies of light emitted by a source, such as an atom, molecule, or celestial object. It shows...

End-fire coupling refers to a method of coupling energy into or out of a waveguide, transmission line, or antenna, where the electromagnetic waves are directed primarily along the axis or direction...

1. The use of an electronic microdensitometer to measure points of equal density on a photographic deposit. 2. A technique that simplifies a picture's density pattern by making a single isodensity...

An etalon is an optical device that consists of two parallel reflecting surfaces separated by a precise and known distance. It operates based on the principle of optical interference and is used to...

Etaloning is an optical phenomenon that occurs in imaging systems, particularly in devices such as spectrometers, interferometers, and cameras. It is characterized by the appearance of interference...

Extreme ultraviolet (EUV) refers to a specific range of electromagnetic radiation in the ultraviolet part of the spectrum. EUV radiation has wavelengths between 10 and 124 nanometers, which...

A pattern on an oscilloscope display that consists of a string of shapes that resemble eyes. Because the pattern becomes more closed with increasing distortion and interference, an open eye diagram...

The spectroscopic analysis of interference patterns using a monochannel spectrometer, spectrograph or multichannel spectrometer with a Fabry-Perot interferometer to record the fringes.

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...

In image processing and machine vision, the process in which an initial measurement pattern or some subsequence of measurement patterns is transformed to a new pattern feature. In image pattern...

A fiber Bragg grating (FBG) is a type of optical filter that is inscribed or "written" into the core of an optical fiber. It consists of a periodic modulation of the refractive index along the length...

A fiber optic gyroscope (FOG) is a type of gyroscope that uses the interference of light waves to detect changes in orientation or rotation. It operates based on the principle of the Sagnac effect,...

Intensity of emission as a function of direction in a given plane.

Fixed-pattern noise is the measure of the static (nontemporal) differences between pixels when the detector is evenly illuminated. In microbolometers, this effect is mostly caused by mismatch between...

Fizeau fringes are interference fringes observed in an interferometer, specifically in a Fizeau interferometer. The Fizeau interferometer is named after the French physicist Armand Fizeau, who...

The moving spot of light emitted by a source, generally a cathode-ray tube, to illuminate specific points of an area carrying light and dark regions according to a specific pattern.

FMCW lidar stands for frequency-modulated continuous wave lidar. It is a type of lidar (light detection and ranging) technology used for remote sensing, distance measurement, and 3D mapping. FMCW...

A laser skin-resurfacing method that creates microscopic thermal wounds referred to as microscopic treatment zones (MTZs), which are surrounded by uninjured tissue. The MTZs are usually arranged in a...

A far-field pattern holographically reproduced image that is categorically considered with three-dimensional lensless photographs.

FTIR (Fourier transform infrared) spectrometer is a powerful analytical instrument used to obtain an infrared spectrum of absorption or emission of a solid, liquid, or gas sample. It operates based...

Graphene is a two-dimensional allotrope of carbon consisting of a single layer of carbon atoms arranged in a hexagonal lattice pattern. It is the basic building block of other carbon-based materials...

1. In a cathode-ray tube, the glow surrounding a bright spot that appears on the fluorescent screen as the result of the screen's light being reflected by the front and rear surfaces of the tube's...

A plate containing a uniform pattern of transparent holes in an opaque background, the clear area being nearly equal to the opaque area. Used in the printing process.

An interference pattern that is recorded on a high-resolution plate, the two interfering beams formed by a coherent beam from a laser and light scattered by an object. If after processing, the plate...

A holographic camera, also known as a holographic imaging system or holographic recorder, is a specialized device used to capture 3D holographic images of objects or scenes. Unlike conventional...

A holographic grating is a type of diffraction grating that is produced using holographic recording techniques. It consists of a periodic structure of alternating transparent and opaque regions,...

The three-dimensional interference pattern of fringes that is recorded on a holographic plate to facilitate the study of a complex object.

The interferometric analysis of a complex object by utilizing the three-dimensional hologram. By causing a laser beam to diverge into two directions, one of which directly strikes a holographic...

A photographic recording of interference patterns between a plane wave and a spherical wave on a high-resolution photographic emulsion.

A component used to modify light rays by diffraction; the HOE is produced by recording the interference pattern of two laser beams and can be used in place of lenses or prisms where diffraction...

Holography is a technique used to capture and reconstruct three-dimensional images using the principles of interference and diffraction of light. Unlike conventional photography, which records only...

A sensor module used in advanced pattern recognition systems, containing signal-processing integrated circuits stacked and connected by a busing circuit.

A camera tube that employs a high-velocity electron beam to scan a photoemissive mosaic and to store electrical charge patterns.