Photonics Dictionary

The emission of gas or de-aeration due to thermal variations and often occurring in a vacuum. In a cleanroom, contamination from the spontaneous emission of absorbed particles.

The partially reflective mirror at the end of the laser cavity that is the source of the beam. It controls the coupling percentage for high output power and maintains correct mode structure in the...

The direct computation of the Fourier transform of the space variant system output of an optical processor with a single spherical lens. The one-dimensional output spectrum appears along a 45°...

A process for the production of optical fibers. A glass bait is rotated in a traversing flame of a reaction burner. Reactants passed through the flame react with oxygen at the high temperatures to...

The physical distance, measured along the optical axis, from the object to the image. Also called overall length.

A layer of material applied to a coated surface to protect it from physical or chemical action.

The improper exposure of a radiation-sensitive medium that results when there is too much radiation exposing the medium, or when the exposure time is too long. The resulting image, in negative form,...

The condition of the numerical aperture or beam diameter of the laser, LED, or other optical source being larger than the optical fiber core or other driven source. Also called overfilled launch...

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...

A hologram facet illumination technique in which the illuminating beam is twice the size of the hologram facet so that full hologram resolution capability can be realized and scanning dead time is...

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 device that uses a photoelectric cell to determine the level of oxygenation in the blood.

Oxytosis refers to a form of cell death that is induced by oxidative stress. It is characterized by the overproduction of reactive oxygen species (ROS) within cells, leading to oxidative damage and...

In a semiconductor, the state created by the addition of a dopant that creates excess holes.

A semiconductor material in which the dopants create holes as the majority charge carrier. It is formed by doping with acceptor atoms.

The finite amount of electrical charge generated in response to incident radiation and transferred from one storage element to the next in a charge-coupled device. Each packet corresponds to a pixel...

The transmission of data in groups (packets) of information~comma~ each handled as an aggregate.

1. In a photonic interconnect, the number of detectors in a given area. Detectors spaced too closely may give rise to crosstalk. 2. In the cross section of a fiber optic bundle, the ratio of fiber...

The ratio of the active core area of a fiber bundle to the total area at its light-emitting or receiving end.

The production of a positron-electron pair by a photon having energy greater than one mega-electron-volt, whereby some of the photon energy is converted to the rest mass of the pair.

In interlaced television scanning, an effect in which the lines of one field fail to fall exactly within the lines of the following field, both fields comprising one frame of the picture. The lines...

Black and white film that has a wavelength sensitivity similar to that of the eye.

Color sensitivity extended to cover the entire visible spectrum out to the red.

A camera designed to form a continuous record of an expansive section of the horizon. The typical panoramic camera is mounted to rotate about a vertical axis. A slit opening in the film plane and the...

The image distortion produced by a panoramic camera with a swinging lens or a swinging mirror in front of a fixed lens. The magnification is greatest in the center and diminishes to each side in the...

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...

A telescope so manufactured that the image remains erect and the position of the eyepiece is unchanged as the line of sight is pointed in any horizontal direction.

The condition in which the index of refraction in an optical fiber varies as a parabolic function of the radius.

A condenser composed of a paraboloidal reflector and used for dark-field illumination.

A concave mirror that has the form of a paraboloid of revolution. The paraboloidal mirror may have only a portion of a paraboloidal surface through which the axis does not pass, and is known as an...