Bristol Instruments, Inc. - 872 Series High-Res 4/24 LB

Type

Browse by Letter

SCANLAB GmbH - Laser Beam Deflection 2024 MR

171 terms

Definitions: A

Clear All Filters x Na x Definitions x A x
Abbe illumination

Image of a uniform source through the sample of a microscope image system. Light from the sample plane is reimaged by the objective into the image plane.

absolute luminance threshold

The minimum value of luminance for vision. The value may vary with age as well as dark adaption period. (Measured range approximately log luminance -3 through 2.) About 10 -2 ml at the fovea, 10 -5...

acousto-optic tunable filter

A bulk crystalline optic which permits the propagation of light through a volume of index altered material. The variation in refractive index along the material volume is due to a piezoelectric...

additivity of luminance

The luminance of a mixture of lights is the sum of the luminances of the component lights in the mixture.

advanced tactical air reconnaissance system

An aerial reconnaissance system that can transmit, in near real time, image data recorded by IR and visual-spectrum sensors, providing day, night and foul-weather intelligence.

aerial reconnaissance

The use of optical or electronic recording systems to extract information from the terrain, while aloft, for reconnaissance applications.

allyl diglycol carbonate

Commonly known as CR39, this thermosetting plastic is used in the casting of eyeglass lenses because of its toughness and clarity.

anaglyph

An image that can be studied three-dimensionally through a pair of complementary color filters composed of two superimposed views.

analog

A physical variable that is proportionally similar to another variable over a specified range. An analog recording contains data that is similar to the source.

analog output

Information presented as a continuously variable relationship between a signal and a standard.

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-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.

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...

annealing furnace

An oven or furnace that possesses the design requirements and heat control necessary to anneal glass for the optical industry.

antiresonance

Literally the opposite of resonance, antiresonance occurs when any variation in excitation frequency results in an increased response.

aperture illumination

The amplitude, polarization and phase contained in the field distribution over the aperture.

aplanat

Also known as aplanatic lens. A lens corrected for spherical aberration and coma.

aplanatic lens system

A system that satisfies the Abbe sine condition, and is free from spherical aberration and coma.

aplanatic points

Aplanatic points refer to specific points in an optical system where certain aberrations, such as spherical aberration or coma, are minimized or eliminated. In an optical system, aberrations are...

aplanatic surface

An aplanatic surface is an optical surface that is specifically designed or shaped to minimize spherical aberration and coma. Spherical aberration is an optical aberration that occurs when light rays...

apparent luminance

The perceived brightness of an object being viewed at some distance, especially through an optical instrument.

absolute temperature scale

The measurement of heat energy as determined from absolute zero as the zero point on the scale. Increments are identical to the Celsius as well as Kelvin scales.

apostilb

A unit of luminance equal to 1/p candela per square meter.

aptamer

An aptamer is a short, single-stranded DNA or RNA molecule that can bind to a specific target molecule with high affinity and specificity. Aptamers are often referred to as chemical antibodies due to...

atomic time

Any system of time measurement that is based on atomic resonances. The transition times between the hyperfine levels of cesium-133 have been accepted as the international standard.

Abaxial ray

Ray oriented and assumed to propagate orthogonal to the optical axis

Abbe prism

A form of roof prism used to invert an image. The prism has faces cut normal to the optical axis; therefore, the prism may be placed within the optical path of a system and invert the image without...

Abbe refractometer

Device which measures the index of refraction of glass as well as the dispersion over visible range.

Abbe-Porro prism

A reflecting prism that inverts the image. The image is reflected four times internally and emitted laterally. The prism is cut normal to the optical axis while the image is internally reflected from...

aberration

A departure from ideal paraxial imaging behavior. The distortion of an optical field wavefront as it is propagated through the elements of an optical system. The field distortion is due to the...

aberration sensor (wavefront sensor)

Designed for the function of optical wavefront analysis. Shack-Hartmann camera aberration sensors use a lens array to image the wavefront to the CCD image plane. Live feedback may be applied through...

ablation -> laser ablation

Laser ablation is a process that involves the removal or erosion of material from a target surface using laser energy. This technique is widely used in various scientific, industrial, and medical...

ablative photodecomposition

Ablation applied to polymers and chemical solids. Process of material removal that minimizes edge damage but will not heat the surrounding portion of the sample.

Abney effect

The alteration and reduction of color with the addition of white light. The perceived color shift that occurs as the monochromatic-white combination meets the eye and is interpreted by the brain. The...

absolute colorimetric

Method of preserving the measured color value and color information as it is translated from differing devices. For example the output of a television display may be measured to have an identical...

absolute purity threshold

Least value of color value combinations which gives white light; minimum purity as determined to be white.

absorbance

The natural log of the ratio of absorbed intensity over the total intensity which gives a constant value assuming a stable volume as well as energy. In optical physics the absorbance may be defined...

Photonics DictionaryDefinitionsA