Photonics Dictionary

A system of elements which rotates the optical image with respect to the optical axis by a factor of pi radians.

A television camera tube that preceded the development of the vidicon tube and incorporated a method to separate reflected and scattered portions of the return beam so that only the scattered...

In optics, the term image jump refers to a displacement or shift in the apparent position of an image when a change occurs in the optical system. This phenomenon is often observed in certain types of...

The active control of various aspects (optical element position, airspace thickness, etc.) of an optical system that compensates for unwanted movement of the image that is caused by mechanical and...

Any form of lens, optical system (camera, telescope, microscope, etc.), or opto-electronics utilized for the purpose of producing an image of a given object.

A camera tube widely used in television broadcasting. It consists of three sections within a single vacuum envelope. 1. A photosensitive film sometimes called the photocathode. The scene to be...

Photon flow created by imaging of light into a detector array; IPD is the electrical signal used by the image processor in a laser radar angular tracking system.

A plane in which an image is formed. A real image formed by a positive lens would be visible upon a screen located in this plane.

A hologram in which the image of an object, or the object itself, is located near the hologram recording plane, for optimum image reconstruction. Because the images are close to the hologram plane,...

A device embodying a microprocessor that converts an image to digital form and then further enhances the image to prepare it for computer or visual analysis.

A measure of the closeness with which an optical image is capable of resembling the original object. The factors that affect image quality are lens aberrations, diffraction, dirt and stray light...

The multiple storage of a single image.

Filtering procedures aimed at estimating the original image by removing the blurring and noise suppression that occur during image processing.

A type of electroluminescent display that will record and maintain an irradiated image on its phosphor screen, provided a DC potential is applied to the screen. Used to record x-ray images, the...

An image signal processor (ISP) is a hardware component or subsystem in digital imaging devices responsible for capturing, processing, and enhancing images from a camera sensor. The ISP performs...

An eyepiece having a special prism arrangement linked to a micrometer screw to allow reading of the angular relations between the two prism segments to be varied. When the prism faces are parallel,...

A modified form of an image-retaining panel that can be used in subdued daylight. This is achieved by adding a layer of zinc oxide between the panel's phosphor layer and its rear electrode. The zinc...

A method used to compare two pictures of the same subject taken at different times. See image comparison.

Any arrangement of a bundle of optical fibers that alters the shape of the image. For example, by systematic regulation of the spacing of the fibers from the entrance end to the exit end, a...

The processing of an image or portion of an image by transform coding and analysis. Fourier, Hadamand, Kronecker and Eigenvector transforms are applicable to image transformation.

A camera system in which the image formed on the fluorescent screen of an image converter tube in the system is recorded by photography or direct contact printing from the face of the tube.

The distance between the last vertex of a lens and the image.

Complex devices, often involving a computer, in which a photograph is scanned by a point of light, the amplitude of the electrical signal being modified electronically before being re-recorded on...

Photogrammetric compensation for incidental camera movement (which prevents attainment of true vertical photographs) whereby the imagery is copied in an oblique plane camera system.

The science of producing, recording, storing, transmitting and displaying visual images by any system (photographic, video, facsimile, etc.) in any form.

A thermoplastic or thermosetting material used to hold an object fixed and keep it from deterioration. In microcircuitry, the process of imbedding is known as potting.

A radiation detector with its active medium mounted within a lens that focuses the radiation signal. The improvement in detector performance is a function of the indices of refraction of the lens...

Term synonymous with refractive index liquid, but related more to tank or chamber immersion of crystals, fibers, lenses, photoelastic models, etc.

An oil required by oil-immersion objectives that is applied between the exterior of the objective lens and a cover glass or appropriate specimen.

A type of refractometer designed to measure the refractive indices of liquids. A section of the instrument is immersed into the sample being measured.

The technique that uses light to detect and analyze the antibodies produced by a specimen stained with an organic dye.

Immunohistochemistry (IHC) is a method for detecting antigens or haptens in cells of a tissue section by using labeled antibodies to bind specifically to their antigens. IHC is used for disease...

Fluorescence formed when atoms of one element collide with excited atoms of another.

Qualitatively, the inverse of the amount of velocity produced by the application of a sinusoidal force to a system; therefore, if velocity is high, impedance at that point is low. Quantitatively,...

An alien, electrically charged atomic system in a solid; an ion substituted for the constituent atom or ion in a crystal lattice, or located in an interstitial site in the crystal.

In the context of optical materials, the term "impurity level" refers to the presence of foreign atoms or molecules within the material that deviate from its regular or intrinsic composition. These...

That state determining that two waves of like frequency will travel through their maximum and minimum values of the same polarity simultaneously.

In vitro is a Latin term that translates to "in glass." In scientific contexts, particularly in biology and medicine, it refers to experiments or procedures conducted outside of a living organism,...

In vivo is a Latin term that translates to "within the living." In scientific contexts, particularly in biology and medicine, it refers to experiments or observations conducted within a living...

The formation of a hologram by single reference-beam interferences with waves that are diffracted or scattered from a small object.

The emission of light by thermal radiation of a temperature high enough to render the source of radiation visible.

Flux incident per unit area of a surface.

A ray of light that falls upon or strikes a surface of an object such as a lens. It is said to be incident to the surface.

The presence, within the body of the glass, of extraneous or alien material. See seed; striae.

In optics, the term denoting the lack of a fixed phase relationship between two waves. If two incoherent waves are superimposed, interference effects cannot last longer than the individual coherent...

A bundle of filaments of optical glass or other transparent materials that transmit only light, not optical images. The arrangement of the individual fibers in the bundle is not sufficiently regular...

The production of holograms initially from either conventional photographs or incoherent optical equipment.

A flaw deliberately introduced into an optical fiber to prepare it for cleaving.