Photonics Dictionary

The deformation of a material at high levels of stress, often associated with elevated temperatures.

In ophthalmic practice, an instrument that determines the boundaries of the field of view. It is composed of a 2-m square of black velvet with a white spot center at which the patient, 1 m away,...

A photometer screen that contains a diaphragm of paper or parchment with a translucent central spot of oil or paraffin.

In printing, a translucent screen used with lenses to provide an even distribution of diffused light.

In a camera, the focusing of an image on the screen located at the camera's film plane. Once the image is in complete focus, the recording medium is inserted in place of the screen.

A CRT screen on which two phosphors differing in color and persistence are deposited.

A fluorescent screen refers to a phosphorescent or fluorescent-coated surface that emits visible light when exposed to other forms of electromagnetic radiation, such as x-rays or ultraviolet light....

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.

Also known as HCS, an analytical method designed to collect statistically relevant amounts of quantitative data on many parallel cell populations or processes within cells through the combination of...

A screen with a reflected or transmitted light beam that is confined to a much smaller bundle than was received by the screen, thereby resulting in a higher luminance.

A thermal infrared imaging procedure developed for quality control of printed circuit boards. The thermogram of each board under test is compared with a standard thermal profile and then with a...

A rear or front projection screen composed of minute optical surfaces that introduce a spread to the light beam that conforms approximately to the light distribution requirements of the application.

A lenticular screen having the lenticules tipped about 20° to compensate for off-normal projection.

A phase screen, in the context of optics and wave optics, refers to a surface or medium that introduces a phase delay to an incident wavefront passing through it. This concept is often used in the...

A solid-state panel of the photoconductor-electroluminescent type. The photoconductive layer, sensitive to x-rays, is coated by the electroluminescent, which gives the visible image. When the former...

The transparent component of an optical reader that transmits the image rays of the characters to be read.

The large, usually flat surface onto which an image is projected for viewing. May be reflecting or transmitting (rear projection).

A projection screen having vertical ribs or flutes set into a plastic surface.

A screen composed of a sheet of diffusing plastic material that reveals excellent image detail for close viewing. It is efficient for use with microfilm readers.

A cathode-ray tube having a screen that is coated on the back with a thin film of aluminum, which serves to intensify the propagation of light.

An analog method of moving a cathode-ray tube beam across a display screen face, commonly used in high-performance vector and character generators.

Also known as a shadow mask, a perforated plate placed between the focusing and accelerating electrodes, and the tricolor phosphor screen in a color-television tube.

With respect to pictorial displays, the ratio of the width to the height. The television standard in the US is 4:3. High-definition or wide-screen television will have a ratio of 16:9.

The principle stating that two diffraction screens, one being exactly the negative of the other, will form the same diffraction patterns.

Refers to a display or screen that is illuminated from behind; the light is transmitted as opposed to reflected.

In computer graphics, the point on the display screen where the electron beam is located before the display instruction is executed. On directed beam display points, vectors and other graphic...

Light interference fringes that can be viewed on a screen near a biprism.

In computer graphics, the assignment of each pixel on a display screen to its own switch in the computer memory.

The luminous trace formed on the cathode-ray tube screen by the motion of the electron beam.

A vacuum tube with an electron gun at one end and a fluorescent screen at the other. Electrons emitted from a heated filament are accelerated by a series of annular anodes at progressively higher...

Computer hardware or firmware that accesses character patterns stored in read-only memory and displays them at specific coordinates on a screen.

The application of a cine camera in recording the images on a fluorescent screen. When x-rays are used to produce the screen images, this process is referred to as cine-radiography.

The photographic filming of the action of x-ray images recorded on a fluorescent screen by means of large lens apertures and highly sensitive filters.

A camera system capable of producing microfilm copies of computerized data presented on a screen.

A fluorographic method whereby the sensitive photographic medium is pressed against a fluorescent screen to form a visible image.

An inspection device in which the profile of a mechanical part is projected onto a ground-glass screen at a precisely known magnification so that the shape of the part can be compared with a scale...

The progressive defocusing of a cathode-ray tube display image that occurs when the deflected electron beam impinges on the cathode-ray tube screen at a slant.

1. An optical device used for projection of enlarged images of transparencies or lantern slides on a screen. 2. A device designed to hold and backlight transparencies so that their images can be...

The interference pattern formed by light waves diffracted at the edges of an object as seen on a screen placed in their path.

An optical diffuser is an optical component or material designed to scatter or diffuse light that passes through it. It is used to create a more even or uniform illumination, reduce glare, or soften...

A digital camera is a device that captures and records still images or video in digital format. Unlike traditional film cameras, which use photographic film to capture and store images, digital...

Medical diagnostic (x-ray) imaging using laser printers to produce high-resolution digital hard copy instead of film exposed by phosphor-intensifying screens, thus providing radiologists with greater...

The observable illustration of an image, scene or data on a screen such as a console or cathode-ray tube, seen as a graph, report or drawing.

A cathode-ray tube that increases the brightness or size of an image or forms a visible image from invisible radiation. The focal plane for the optical image is a large, light-sensitive, cold...

The photographic recording of images produced by the electrons from an electron microscope. The electron beam carries the images through an array of three lenses, and an enlarged electron image is...

An electron-beam tube with power-handling capability that is essentially based on controlled electron beams. Its control and screen grids are basically in alignment.

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