Photonics Dictionary

A filter, pale purple in color, used in black and white photography to display the brightness values of a subject being recorded on film.

The observation of a reproduced television picture on the face of a cathode-ray tube.

With respect to laser radiation, the subjection of the human eye to all or a portion of the laser beam.

Laser viewing cards, also known as laser alignment cards or laser safety cards, are specialized cards or sheets designed to visualize laser beams or assist in aligning optical equipment while...

AC thin film electroluminescent (ACTFEL) display devices are a type of flat-panel display technology that uses electroluminescence to produce visible light. Structure: They consist of a thin...

A cylindrical convex viewing mirror used for viewing distorted pictures formed by photographing the reflections of the objects in a similar type of mirror.

In astronomy, the method of deliberately viewing objects with peripheral vision to take advantage of the eye's greater sensitivity to faint light a few degrees from the optical center.

A microscope designed with two eyepieces (oculars), permitting the use of both eyes when viewing through the instrument.

A term pertaining to devices (generally optical) designed for use with both eyes viewing through a single exit pupil. The term may be distinguished from binocular in that biocular instruments contain...

Catoptrics is the field of optics concerned with the reflection of light from reflective surfaces such as mirrors. It encompasses the study and analysis of how light rays interact with these...

A compound prism consisting of an assembly of small prisms cemented together that is used in a coincidence rangefinder to transmit the images from the two objectives to a single eyepiece for viewing.

An optical instrument used to determine the distance to a target being viewed. Two similar optical systems view the target via 45° mirrors at the ends of a fixed baseline. One system creates the...

The direct appreciation of the distance between a given object and the observer, or between the front and back of a solid object. Real depth perception is achieved by the retinal disparity formed by...

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...

The utilization of the light produced when electrical energy is directly converted into light within devices used for visual readout displays or as complex logic-circuit elements. With EL lighting,...

An electrophoretic display, often referred to as an electronic paper display or e-paper display, is a type of electronic visual display technology used in electronic devices for the purpose of...

An endoscope is a medical device used for visualizing and examining the interior of hollow organs, body cavities, or confined spaces within the body. It consists of a flexible or rigid tube equipped...

A fiber optic imaging bundle is a specialized optical device composed of multiple optical fibers bundled together. Each fiber optic strand within the bundle acts as a conduit for transmitting light....

The length of the small space within which the atmosphere exhibits coherence, particularly in relation to an observer on Earth viewing celestial objects. The turbulence of the Earth's atmosphere...

Metamerism that occurs when the geometry of illumination or viewing is changed.

In a microscope, the diaphragm located between the Bertrand lens and the eyepiece, which is closed during conoscopic viewing to restrict the interference figures to that of a crystal lying on the...

A specific, right-angle prism having a transmission grating replicated on its hypotenuse face and used in applications requiring a system that can produce in-line viewing for one wavelength.

A device small enough to be held in a hand that uses a magnifying lens and a translucent back to permit the viewing of photographic transparencies.

A desklike apparatus with an opal glass surface illuminated from beneath by fluorescent tubes. It is equipped with roll holders for aerial films and a low-power microscope or some form of...

In computer graphics, the coordinated two-dimensional or three-dimensional area of increased resolution where graphics entities may be defined. The screen represents a viewing window for this area,...

A type of microscope that uses radiation in the infrared region to illuminate objects that are opaque to visible radiation. The microscope consists of two illumination systems (transmitted and...

An infrared source combined with reflecting projection optics to illuminate a target making it visible when observed through an infrared viewing device.

A small round mirror on the end of a handle used for viewing inside an inaccessible cavity.

The distance between the two eye pupils when the observer is viewing distant objects (normal = 62 mm).

The apparent visual angle that divides intrabeam viewing from extended-source viewing.

The line of vision; the optical axis of a telescope or other observation system. The straight line connecting the object and the objective lens of the viewing device.

Liquid crystal on silicon (LCoS) is a display technology that combines liquid crystal materials with silicon-based semiconductor technology to create high-resolution, high-quality images. LCoS...

A subtractive colorimeter that expresses a liquid's or object's color as a combination of three colors. These colors are developed through viewing the specimen object through three series of slides,...

1. A framelike structure that serves to restrict the viewing area of the screen when placed before a television picture tube. 2. In photolithography, a photomask (or mask) is typically a patterned...

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 binocular microscope designed for the viewing of stereo pairs. As these stereoscopic image pairs are seen through a microstereoscope, they are merged into a single image allowing the brain to...

A near-eye display (NED) is a type of display technology designed to be positioned close to the user's eyes, typically within a few centimeters. This technology is commonly used in applications such...

Ocular accommodation is the process by which the eye changes its optical power to maintain a clear image (focus) on an object as its distance varies. This process is essential for seeing objects at...

Optical design software refers to specialized computer programs used by optical engineers, physicists, and designers to simulate, model, analyze, and optimize the performance of optical systems and...

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 pentaprism is a five-sided glass prism used in optical devices, particularly in SLR cameras, to deviate the path of light by 90 degrees and ensure that the image seen through the viewfinder is...

The distortion that is the result of viewing a print from a point other than the center of perspective. The center of perspective is that viewpoint at which the angular subtenses of points in the...

A still or motion-picture camera designed to photograph through a microscope. Photomicrographic equipment usually contains a beamsplitter or other means for simultaneously viewing, orienting and...

A Huygenian eyepiece containing a pointer at its focal plane that is used -- when viewing an object through the eyepiece -- for specific designation.

An instrument that uses an image intensifier to aid in the viewing of subjects in low-light-level environments.

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

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

An instrument used for viewing in low levels of illumination by means of infrared radiation. A high-aperture lens forms an image of distant objects on the photocathode of an infrared-sensitive image...

The photographing of a scene from positions corresponding to the locations of both eyes. A viewing device is used to present one picture to each eye for fusion of the retinal images, giving a...