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DataRay Inc. - ISO 11146-Compliant Laser Beam Profilers
Photonics Marketplace
416 terms

Definitions: A

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analog signal
A signal in the form of continuously variable voltage or current.
analog stroke
An analog method of moving a cathode-ray tube beam across a display screen face, commonly used in high-performance vector and character generators.
analog thermogram -> thermogram
Also known as analog thermogram. The resultant photograph, illustrating, in tones ranging from black to white, the spatial relationship of the infrared radiation temperatures of the different details...
analog-to-analog
Analog-to-analog (AA) refers to the process or system that involves the conversion or transmission of analog signals from one form to another, without converting them into digital signals at any...
analog-to-digital converter
A device that converts an analog signal, that is, a signal in the form of a continuously variable voltage or current, to a digital signal in the form of bits.
analog-to-digital
Analog-to-digital (A/D) is a process that converts continuous analog signals into discrete digital signals. This process coverts analog signals continuously, which vary smoothly over time, into a...
analytical photogrammetry
The use of mathematical analysis to derive solutions in the science of photogrammetry.
analytical photography
The use of photographs -- motion picture or still -- to establish if a particular event exists.
analytical phototriangulation
The use of photographs taken from specially placed cameras, to develop, through computation, a spatial solution of the photographed phenomenon.
analyzer
An optical device, such as a Nicol prism, capable of producing plane-polarized light, and used for detecting the effect of the object on plane-polarized light produced by the polarizer.
anamorphic
A term used to denote a difference in magnification along mutually perpendicular meridians. Anamorphic systems are basically image-distorting systems, such as those used in motion pictures, that...
anamorphic distortion
A type of distortion in which the magnification varies in different orientations, the directions of maximum and minimum magnification being orthogonal.
anamorphic lens
A lens, usually having one or more cylindrical surfaces, used to produce distorted images and later to restore them to true form.
anamorphic system
An optical system with different focal lengths or magnification levels in perpendicular planes to the optical axis.
anamorphoscope
A cylindrical convex viewing mirror used for viewing distorted pictures formed by photographing the reflections of the objects in a similar type of mirror.
anamorphosis
A state in which an image is distorted by an optical system.
anamorphote lens
A lens that distorts an optical image.
anastigmat
A compound lens combination whose astigmatic difference is zero for one or more off-axis zones in the image plane. In such a lens the other aberrations are sufficiently well-corrected to yield...
angle gauge
A glass or metal measurement tool having a precisely calibrated angle between two of its faces.
angle of convergence
An angle formed by the lines of sight of both eyes when focusing on an object. Also, the rate at which a ray approaches the optical axis.
angle of deflection
The angle through which a beam is deflected.
angle of deviation
The angle through which a ray of light is deviated by a refracting or reflecting surface, or a prism; the angle between an incident ray and the refracted or reflected ray.
angle of elevation
The angle between an instrument's line of sight and a reference horizontal plane.
angle of incidence
The angle formed between a ray of light striking a surface and the normal to that surface at the point of incidence.
angle of reflection
The angle formed between the normal to a surface and the reflected ray. This angle lies in a common plane with the angle of incidence and is equal to it.
angle of refraction
The angle formed between a refracted ray and the normal to the surface. This angle lies in a common plane with the angle of incidence. See also Snell's law of refraction.
angle-tracking system
A system in which a sequence of direct measurements of the target position is fed into a tracking filter that may produce refined estimates of past, present and future target positions.
Angstrom coefficient
The coefficient Å in Angstrom's formula for the dispersing coefficient for dust present in the atmosphere. The formula is expressed as S × Ål-B where l represents wavelength and B...
Angstrom compensation pyrheliometer
A system used for measuring direct solar radiation.
Angstrom mode
An operational mode for radiometers that analogs the method of operation of an angstrom pyrheliometer. In this mode, the rearward-facing cavity is electrically heated, while the forward cavity is...
angstrom
An angstrom, symbolized by the Ångström or Å, is a unit of length used to express atomic and molecular dimensions. It is equal to 0.1 nanometers or 1 × 10-10 meters. The...
angular aperture
The angle between the most divergent rays that can pass through the lens to form an image. In a birefringent crystal light modulator or Pockels cell, the maximum angle in the incident light rays that...
angular magnification -> magnification
The ratio of the size of the image of an object to that of the object. The ratio of the linear size of the image to that of the object is lateral magnification. Angular magnification is the ratio of...
angular misalignment
Angular deviation from the optimum alignment of source to optical waveguide, waveguide to waveguide, or waveguide to detector, resulting in a loss of optical power.
angular spectrum approach
The angular spectrum approach is a mathematical and computational technique used in the field of optics to analyze and simulate the propagation of optical waves, particularly in the context of wave...
angular subtense
The measured planar or solid angle of related aspects of an optical system with respect to an optical axis.
angular tracking
A laser radar application in which a sequence of direct measurements of target position is fed into a tracking filter to produce refined estimates of both present and future target positions.
aniseikonia
A visual defect that produces a disparity in the sizes of the images formed by the two eyes.
anisophotic source
A light source that emits an uneven distribution of radiant energy through the visible range.
anisotropic
Anisotropic is a term used to describe a material or substance that exhibits different properties or behaviors in different directions. In other words, the physical or mechanical characteristics of...
anisotropy
Anisotropy refers to the property of exhibiting different values or characteristics when measured in different directions. In various fields, including physics, materials science, and geology,...
annealing
The process of heating and slowly cooling a solid material, like glass or metal, to stabilize its thermal, electrical or optical properties or, as in semiconductor materials, to reverse lattice...
annealing furnace
An oven or furnace that possesses the design requirements and heat control necessary to anneal glass for the optical industry.
annihilation radiation
Gamma ray radiation released when matter and antimatter, such as electron and positron, unite and eliminate each other, transforming completely into energy. The resulting gamma ray spectrum depends...
annular eclipse
A type of solar eclipse that occurs when the sun is at perihelion and the moon is at apogee. Because the apparent size of the moon is insufficient to cover the sun, the outer edge of the solar disc...
anode
The part of an electrical circuit in which the electrons leave (a cathode-ray tube) or enter (an electrolytic cell) a unit in the circuit.
anomaloscope
An optical instrument that uses a yellow light of varying intensity with red and blue lights of fixed intensity to test for colorblindness.
anomalous dispersion
Dispersion that occurs when the medium's index of refraction decreases as the frequency of the propagating light increases. For a given medium, some wavelength ranges may produce anomalous dispersion...
anomalous photoconductivity
A spectral phenomenon in which the degree of the photoresponse of an illuminated semiconductor is determined by the wavelength composition of the incident light.
anomalous propagation
Irregular propagation of a wave due to variations in the medium's density or refractive index.

Photonics DictionaryDefinitionsA

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