Photonics Dictionary

A type of refractometer designed to measure the refractive indices of liquids. A section of the instrument is immersed into the sample being measured.

A system that uses infrared detectors and related instrumentation to determine when abnormal amounts of infrared radiation, usually in the form of heat, are present in an area; used for the detection...

An instrument, similar in design to regular binoculars, that can transmit and enlarge infrared images.

An infrared camera, also known as a thermal imaging camera or IR camera, is a device that captures and visualizes the infrared radiation emitted by objects, revealing temperature variations across...

Any of the photoelectric and thermal detectors, spectrographs and monochromators, thermographs, scanners, amplifier tubes, snooperscopes and related equipment developed for use with infrared...

An infrared lens is an optical component specifically designed and optimized for transmitting, focusing, or manipulating infrared (IR) radiation within the infrared spectrum. These lenses are used in...

The process of mapping the infrared emittance of an area through the use of an infrared detector and related scanning instrumentation to produce thermal images that are then recorded on photographic...

An InGaAs photodiode refers to a photodetector device that is constructed using a semiconductor material composed of a combination of indium (In), gallium (Ga), and arsenic (As). The term InGaAs...

Instantaneous field of view (iFOV) is a term commonly used in the context of remote sensing, imaging systems, and optical instruments. It refers to the specific portion of a scene that an optical...

The tendency to adjust an instrument such as a microscope so that the viewed image appears much closer than infinity.

An instrument that employs the interference of lightwaves to measure the accuracy of optical surfaces; it can measure a length in terms of the length of a wave of light by using interference...

The separation between the exit pupils of a binocular instrument. This usually is adjustable so that it can be set equal to the observer's interocular distance, a normal range being from 55 to 75 mm.

A material often used in the construction of optical instruments because of its low coefficient of thermal expansion (0.9 x 10-6/ °C).

Also known as the Bragg spectrometer. A system used for the x-ray analysis of crystal structure. In the instrument, a homogeneous beam of x-rays is directed on the known face of a crystal and the...

An instrument designed to measure the index of refraction of a gas by the interference patterns formed by two beams, one of which passes through a vacuum tube in which the gas is slowly released.

An optical instrument containing a gimballed sighting telescope, used to measure angular relationships in horizontal and vertical planes.

A simple form of astronomical telescope that uses a fixed objective and a focusable eyepiece. The objective forms an intermediate image in the instrument, resulting in an image that appears upside...

An imaging device originally created to image whole mouse brain volumes at microscopic resolution. The main component of the instrument is an automated microtome and microscope capable of producing...

An endoscopic surgical instrument that includes a channel for the introduction of supplementary instruments.

A device used for measuring the height of clouds from a position on the ground. Measurement technique uses a vertically directed beam stably positioned such that scattered radiation may be detected...

Laser cooling is a technique used to reduce the temperature of a material or a collection of atoms or molecules by using laser light. It is based on the principle of selective absorption and emission...

An instrument usually consisting of a very long interferometer, 3 to 800 m, and a laser light source for the study and measurement of strain, such as those formed by earth tides and gravitational...

A Laurent polarimeter is an instrument used in optics for measuring the rotation of plane-polarized light caused by optically active substances. Optical rotation, also known as optical activity, is a...

Lens testing equipment refers to a range of specialized tools and instruments used to evaluate the optical performance, quality, and characteristics of lenses. These instruments are essential for...

An ophthalmic instrument used to measure the magnitude and direction of the maximum and minimum powers of a spectacle lens, and mark the optical center of the lens by an ink dot. When the lens to be...

A spectrum formed by radiation whose energy values of the property being measured cluster about at least one discrete value, as opposed to a continuous spectrum. The actual width of the spectral line...

In data communications, the instrumentation connecting two stations: transmitters, receivers and the cable that runs between them.

A small half-shade analyzer placed in the eyepiece of a polarimeter to determine the character of the polarized light emitted by the instrument. It consists of a Nicol prism situated so that it...

A lock-in amplifier is a specialized electronic instrument used to extract and measure small signals embedded in noise or interference. It is particularly useful in fields such as spectroscopy,...

Instrumentation designed to permit the perception, recording or measurement of scenes under conditions of low incident illumination.

A photometric instrument having two prisms clamped in optical contact to produce a photometric field with an acute dividing line.

An instrument used to record sound, pictures or both on a magnetic tape for storage and playback.

A magnetometer is a scientific instrument used to measure the strength and/or direction of a magnetic field. It can detect and quantify the intensity of magnetic fields in its vicinity. Magnetometers...

Instrument that uses absorption spectroscopy to detect gases in planetary atmospheres. Dispersed incoming radiation is transmitted to one or more sampling elements, or masks, before reaching the...

An instrument that uses electromagnetic fields to sort out the relative masses of atoms and molecules.The same way an optical spectroscope uses a prism to separate light into its various wavelengths,...

A spectrum that displays the distribution in mass or in mass-to-charge ratio of ionized atoms, molecules or molecular parts. Mass spectrums are typically recorded by instruments utilized in mass...

In the field of optics and imaging, a mesoscope refers to an optical instrument that is designed to observe and capture images at intermediate scales, falling between microscopic and macroscopic...

1. The basic unit of length in the metric system, equal to 39.37 in. or 3.28 ft. 2. Any device or instrument used for measuring. The term often appears in conjunction with the quantity it measures,...

Metrology is the science and practice of measurement. It encompasses the theoretical and practical aspects of measurement, including the development of measurement standards, techniques, and...

The fundamental tool of microdensitometry, the microdensitometer is an instrument used for the precise measurement of microscopic optical densities (i.e. optical absorption) by detection of faint...

A graphic reproduction of an object formed by a microscope or another optical system. Also an instrument used to make tiny writing, etching, or engravings.

An instrument capable of measuring the transmitted or reflected luminance from a very small area seen under a microscope. Microphotometers are the fundamental tools of microphotometry and are also...

An instrument that produces an intense, tightly focused beam of ions to stimulate emissions from a minute section of a sample undergoing spectroscopic analysis. The ion beams found in microprobes are...

A miniature projecting device designed to enhance and reproduce the image generated by a smaller image-forming instrument. Microprojectors can be used to determine the image-forming qualities of...

An instrument consisting essentially of a tube 160 mm long, with an objective lens at the distant end and an eyepiece at the near end. The objective forms a real aerial image of the object in the...

Microscopy is a scientific technique that involves the use of microscopes to observe and study objects that are too small to be seen with the naked eye. Microscopes are instruments that magnify and...

Small tungsten lamp used in surgical instruments such as cystoscopes, and for other purposes where space is limited.