Photonics Dictionary

A camera designed with a telecentric optical system and a narrow field of view; the telecentric optical system (placement of the system's stop at its focal point) ensures that the principal image...

A record formed when the luminous trace or image produced by an oscilloscope is photographed.

An instrument used to record rapidly varying currents or voltages. An oscillograph may consist of a cathode-ray tube oscilloscope with a camera attachment, or a mirror galvanometer with a lamp and...

The graphic recording of physical changes vs. time, in electrical quantities, using an oscilloscope.

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...

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 mounting used for large concave gratings, whereby the slit, grating and plate holder lie in the Rowland circle, and the photographic plates lie along a large portion of the circle. In this way, a...

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...

A hologram that is formed on a recording medium by changing the phase of the illuminating wave in correspondence with the recording exposure. It may be formed by contact printing onto a resist...

In optics and photolithography, a phase mask refers to a device that modifies the phase of light waves passing through it. The phase mask is used to control the spatial distribution of the light's...

An erasable data recording and storage medium that uses a laser to heat the crystalline surface of the disc to a certain temperature, at which it becomes amorphous and records a bit of information;...

A process used in pyrometry and photothermometry to create a photographic record of a surface's temperature gradients. Essentially, it involves the exposure of a glowing phosphorescent surface to the...

A method of producing disks for erasable optical data storage. Information is recorded by a laser beam that generates pits on the surface of the disk while it is being cryogenically cooled. Erasure...

A photographic recording instrument that measures deviation from the vertical of a drilled well or mine.

A device used to count objects that pass a given point by allowing each object to obstruct a beam of light falling on a photocell. Slow counting rates can be recorded by a mechanical counter, but...

The maximum angle of view that can be recorded by a camera. Field is a function of lens focal length and film format.

A form of photometric measurement, often used with light sources that are transparent or fluctuating, in which a photographic plate is used to obtain a record of a source's relative intensities over...

The use of photographic recording equipment to measure radiant energy. With this procedure, many measurements of radiant energy can be recorded simultaneously and permanently.

A measure of the ability of a photographic system to record fine detail. Usually stated in terms of cycles per millimeter on the processed film.

The photographic recording of the heat radiation emitted from various points on the object as corresponding density variations on fast infrared film.

A type of copying camera in which the object is placed on a horizontal easel and photographed by a horizontal camera above the easel through a 90° reversing prism. The image is recorded on a...

The photographic recording of data, in binary form, for storage in memory. Exposure is achieved by a cathode-ray tube or by modulating a continuous-wave laser beam with a Kerr cell, both relative to...

A document-transmitting process that uses a cylinder that rotates the document to be scanned and detected by a photoelectric cell. The cell transforms the light into electrical energy that may be...

An interferometric technique for the generation of precision gratings that allows for sequential exposure of small segments in the writing of a large grating, allowing increased intensity that...

A camera system used for microphotography in which the document to be recorded is on a flat bed, perpendicular to the lens axis. The camera head is located above the copyboard on a column and may be...

A camera system that uses a fine powder to diffract x-rays from the specimen. A beam of monochromatic x-rays passes through a collimator onto the specimen. Diffracted x-rays are recorded on the film...

Protein crystallography is a scientific technique used to determine the three-dimensional structure of proteins at atomic resolution. It involves growing crystals of a protein of interest and then...

A noncontact, nondestructive method of measuring defects in thin composite materials, using a xenon flashtube to generate heat in a sample. A thermal imaging system detects differences in the rates...

Quantitative phase imaging (QPI) is an advanced imaging technique used in microscopy to measure and analyze the optical phase information of transparent specimens. Unlike traditional brightfield...

The analysis of the photographs taken from the radar display of a survey aircraft and used when recording terrain that is obscured by clouds.

The film used in photographic dosimetry to record the types and amounts of ionizing radiation, such as x-rays and gamma rays, present in an area for a set interval of time. The negative produced by...

A photographic camera and processing system used to form a usable record of the subject in a short time, usually a few seconds, for immediate analysis.

In an optical data storage system, denoting the optical head's ability both to record information and to detect it for playback.

That part of a magnetic or optical tape or disc drive that retrieves data from or records data on the recording media.

The coherent wave used to play back a recorded hologram. It is identical to the reference wave used in the generation of the original hologram; part of it is diffracted by the recording medium and...

In holography, the beam of light that is directed from the beamsplitter to the recording medium, where it interferes with the object beam to generate the hologram.

A photographic method used to obtain an image of a subject by means of its reflectance of incident ultraviolet radiation. An ultraviolet source is used to irradiate the subject, while the reflected...

A camera system used for microphotography that has a structure, such as a cylinder or surveyor belt, to rotate the documents to be recorded. The image is fixed relative to film motion and exposure is...

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 record formed on paper by a scanner.

An optical system that records inhomogeneities within a medium by detecting the energy refracted by that portion of the medium in which the inhomogeneity occurs. The image appears in the form of a...

The photomicrographic recording of Schlieren effects, irregular refractions of light from optic surfaces or areas of thin, transparent specimens, generally using a reticle with parallel transparent...

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.

An instrument designed to measure radiation indirectly through the use of several phosphors and a photomultiplier tube. The absorption of radiation by any phosphors results in light flashes that may...

A technique for observing the decay of light emissions from sources following their pulsed excitations, based on recording the arrival time of the first photoelectron after excitation. After many...

The process whereby sound waves are employed to form a three-dimensional image of an object. The process involves generally: the recording of the diffraction pattern of an object exposed to sound...