Photonics Dictionary

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.

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...

Parallel scanning refers to a method of acquiring data or images simultaneously from multiple sources or in parallel, rather than sequentially scanning each source one after another. This approach is...

A device that converts data transmitted in the parallel mode to a sequence of bits at a single frequency for output in the serial mode.

Oscillation in rod and disc amplifiers that critically limits the achievable energy storage.

Characteristic of optical analyses that are limited to infinitesimally small apertures. Also called first-order or Gaussian optics.

One eyepiece of a set having equal distances from their mounting interface to their image plane, permitting freedom to interchange eyepieces without the need to refocus.

In data transmission, a self-checking code using a separate bit (the parity bit) to assure that all bytes of transmitted data contain either an odd or an even number of bits. Upon receipt, the data...

Totally coherent radiation is produced by a purely monochromatic point source. In the real world the energy will have a limited bandwidth and the point source will subtend some angle resulting in...

Particle acceleration refers to the process by which charged particles, such as electrons or protons, gain kinetic energy and increase their velocity. This acceleration can occur in various natural...

A whole-flow-field technique providing instantaneous velocity vector measurements in a cross-section of a flow that is seeded with micron-sized particles. CCD or CMOS cameras and laser light sheets...

An array of lines in the infrared region of the emission spectrum of atomic hydrogen. Their wave numbers are expressed by the equation: where represents the wave number in the reciprocal centimeters,...

Passive optical components are devices or elements used in optical systems that do not require external power or active control to perform their function. These components manipulate light signals...

A passive optical network (PON) is a telecommunications network architecture that uses optical fibers and passive optical components to provide high-speed broadband services to end-users. In a PON...

A pathogen is a biological agent, such as a virus, bacterium, fungus, protozoan, or parasite, that causes disease in its host organism. Pathogens have the capability to invade host tissues,...

Pathogenesis refers to the process by which a disease develops and progresses within an organism. It encompasses the sequence of events and mechanisms that lead to the onset, progression, and...

A device that determines the lens shape in the cutting or edging phase of fabrication. It also is used to denote the arrangement of markings on a reticle.

The number of electrons that can share a principal quantum number by preventing identity between any two electrons' four quantum numbers, thereby permitting the periodic arrangement of the elements.

Present in photocurrent burst, it is the low frequency pulse that corresponds to the light scattered from the beams in the absence of heterodyne mixing.

In a fiber optic guided missile, the point at which the optical fiber pays out from the bobbin on which it is wound.

A thin, stretched plastic membrane cemented to a rigid supporting ring. It may be coated to act as a beamsplitter, for example, in a color camera; it is so thin that no perceptible image doubling...

A form of dispersing prism, often used in monochromators, that consists of a common right-angle prism with a 30° dispersing prism attached to each of its square faces. The spectrum formed by the...

A Peltier cooler, also known as a thermoelectric cooler (TEC) or thermoelectric module, is a solid-state device that uses the Peltier effect to transfer heat between two electrical junctions. It can...

In astronomy, the main lobe of an antenna pattern that has a small angular extent in two mutually perpendicular directions. Invisible in space, it would resemble a searchlight beam.

A five-sided prism containing two reflecting surfaces at 45° to each other, and two refracting faces perpendicular to the entering and emerging beams. The deviation angle of 90° is...

A pentamirror is an optical component found in SLR cameras, composed of multiple flat mirrors arranged in a pentagonal configuration. Its primary function is to redirect light from the camera lens to...

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...

A well-corrected flat-field eyepiece with good eye relief. Similar to a Huygenian.

An optical instrument designed to displace the line of sight in a vertical direction. For submarines and other military uses the periscope is a long tube containing prisms at both ends and...

The term perovskite refers to a specific crystal structure commonly found in various materials. Perovskite structures have a cubic arrangement of oxygen ions, forming a framework within which other...

A microscope equipped with a polarizer, an analyzer and a Bertrand lens to focus on the upper focal plane of the objective. It is used chiefly by mineralogists and crystallographers for...

The grinding and polishing of rock samples, to a thickness of less than 0.05 mm, for study with petrographic microscopes. When mounted on a slide and protected with a cover, these samples, examined...

An optical system used to examine the pharynx.

In optics and photonics, "phase" refers to a property of electromagnetic waves, such as light, that describes the position of a wave at a given point in time within its oscillation cycle. More...