Photonics Dictionary

A sensing or image-forming detector that serves to convert infrared rays into visible signals for communication purposes. Also, a form of telescope that generates visible images on a fluorescent...

Micro-LED (micro-light-emitting diode) refers to a technology that involves the use of very small light-emitting diodes to create displays and lighting systems. These LEDs are miniature versions of...

A microchannel plate (MCP) is a specialized electron multiplier device used in various applications such as particle detection, imaging, spectroscopy, and night vision technology. It consists of a...

A microdisplay is a miniature electronic display technology that is designed to project visual information onto a small screen. Unlike traditional displays, microdisplays are typically very compact...

A device used to view microfilmed documents where the image on film is projected, in magnified form, onto a rear projection screen for viewing.

A fluoroscope equipped with a magnified, fine-grained fluorescent screen to determine the fluorescence emitted by a microscopic source.

A mixed-signal oscilloscope (MSO) is a type of electronic test instrument that combines the capabilities of both a traditional oscilloscope and a logic analyzer. It is designed to capture and display...

The resulting interference pattern generated from moiré deflectometry, the moiré pattern is a pattern developed from interference or light blocking, when gratings, screens or regularly...

Derivative of the half-tone screen process involving the fabrication of a binary pulse-width modulated copy of the continuous-level input using a halftone screen and spatial-filtering single...

Used in halftone screens to change the fundamental sampled spatial frequency of the halftoned picture, as well as varying the width of the pulse-modulated dots or gratings.

Also referred to as a band-stop or band rejection filter; a notch filter is a filter that is designed to screen out a very narrow band of radiation by transmitting most wavelengths with little...

Oleophobic is a term used to describe substances or materials that repel or resist oils. The word oleophobic comes from the Greek words "oleo," meaning oil, and "phobos," meaning fear. Oleophobic...

An opaque projector is a device used for enlarging and projecting images from opaque objects such as printed pages, photographs, or three-dimensional objects onto a screen or surface. Unlike a...

Ophthalmology is a branch of medicine that focuses on the anatomy, physiology, and diseases of the eyes and visual system. Ophthalmologists are medical doctors who specialize in the diagnosis,...

Typically used for the examination of manufactured or engineered parts, an optical gauging device, in which a backlight is used to project the silhouette of an object upon a screen in which the...

The fluorographic method whereby the visible image (as opposed to the x-ray image) is photographed by mounting a camera in front of the fluorescent screen.

Also known as the Wiener spectrum or the noise power spectrum, the optical power spectrum is a fundamental quantity in film-screen image quality evaluation. It is a means of describing image content...

An organic light-emitting diode (OLED) is a type of light-emitting diode (LED) technology that utilizes organic compounds to produce light. OLEDs are commonly used in display technologies, such as...

A system in which a supplied signal causes the deflection of the electron beam in a cathode-ray tube, thus forming a visible trace on the phosphor screen of the tube and providing for examination of...

A projector used to project transparencies. A horizontal 8 x 10-in. stage for writing or laying down preformed transparencies is provided with either an elliptical mirror or a plastic Fresnel lens...

In a cathode-ray tube, the deflection of the beam of the tube over an angle that surpasses the angle that subtends the suitable area of the screen.

A lens system that is capable of producing a 360° image, or one that is very close to that. In recording, the image may be formed on a curved strip of film surrounding the lens, resulting in a...

Very small phosphor particles present on the screen of a picture tube.

Photocells of various kinds used to measure photometric quantities; i.e., intensity, luminance and illuminance. Meter readings are used to express illuminance and, by calibration, to measure...

Pixel pitch refers to the distance between the centers of two adjacent pixels on a display screen or imaging sensor. It is typically measured in millimeters and is a crucial specification in...

A pixel, short for "picture element," is the smallest controllable element of a digital image or display. It is a fundamental unit that represents a single point in a raster image, which is a grid of...

A thermoplastic, self-extinguishing polymer with excellent high-temperature, low-creep and arc resistance properties.

A device that couples a light source to an optical fiber by projecting an image of the source and the fiber core onto a screen where they can be superimposed by micropositioners.

A device used to project a small area of light on a screen for indication.

The measurement of surface temperature by a thermograph that forms a pattern of the heat radiated by the surface on a luminescent screen.

A planar photocathode and a planar phosphor screen mounted in a close-spaced parallel configuration in an evacuated enclosure so that the ensemble of photoelectrons emitted from each photocathode...

The region of the cathode-ray tube phosphor screen restricted by the tube and instrument specification.

Rare-earth elements (REEs) are a group of seventeen chemical elements found in the Earth's crust, characterized by their unique properties and scarcity relative to other elements. Despite their name,...

The vertical or horizontal distance between two addressable points on a display screen; indicates the basic resolution element of a terminal.

An image that is formed when rays emerging from an optical system all converge to a point on the optical axis. A real image can be seen on a screen in the image space of the given optical system.

RGB stands for red, green, blue, which are the primary colors of light used in additive color mixing. The RGB color model is widely used in various electronic displays, such as computer monitors,...

Rate at which an image on a computer screen is redrawn (usually 50 or 60 Hz) to prevent flicker caused by the decay of the visual image.

1. A device used to trace out an object and build up an image. One of the most common of these types is video scanning. The scanning takes place inside the television tube as electrons, guided by...

The spot illuminated on a cathode-ray tube by the initial impact of the scanning ray and the screen.

A pinhole camera used to record a radioactive tracer's distribution in a subject by means of a scintillation counter or a fluorescent screen; used when a recording emulsion is not practical.

A type of color-generating cathode-ray tube that uses a shadow mask, a thin perforated electrode, located close to the display screen. Each hole in the mask coincides with a triad of three phosphor...

A method of demonstration or examination using a point source illumination without the use of any projection lens between the object and its shadow, the shadow being cast on a distant screen.

A passive infrared system that uses two line-of-sight telescopes to generate both narrow and wide field-of-view images of the same target area, which can be presented on a single split screen or on...

A system employing a dark trace tube in which the opacity of the screen is varied as a function of the power of the beam.

An optical projection device designed to project positive color transparencies onto a screen for viewing.

Spatial resolution refers to the level of detail or granularity in an image or a spatial dataset. It is a measure of the smallest discernible or resolvable features in the spatial domain, typically...

In infrared imaging systems used for mass screening of printed circuit boards or other quality control applications, an image of an ideal component that is stored in the system's memory and then...