Photonics Dictionary

Two or more lenses arranged to act in conjunction with one another.

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 type of stereoscopic photography in which a pair of lenses focuses a pair of images, relative to the positions of the two eyes, onto film through a lenticular screen, which records the images as an...

The stereo image that is recorded by the lenticular, stereo photographic process.

Leukocytes, commonly known as white blood cells, are a crucial component of the immune system in vertebrates, including humans. These cells are responsible for defending the body against infections...

A homogeneous optical medium or coating that transmits only in particular regions of the spectrum. It is used to change or modify the total or relative energy distribution of a beam of light.

Any device that is used to sense and measure light. See exposure meter; photoelectric exposure meter; photoelectric photometer; reflected light meter.

In optics, a pattern, such as the Buchmann-Meyer pattern, that may be viewed when the record surface is illuminated by a light beam having parallel rays.

A PN-PN device with incident light taking the place of gate current; three of the four semiconductor regions are available for circuit connections.

Similar to LASCR, except that all four regions are available.

Technology that relies on a highly efficient photodetector that can detect incoming light signals at one frequency and transmit outgoing signals at another, thus permitting the sending and receiving...

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

A Michelson-type interference microscope used to produce interference patterns of reflective specimens through the interference between light reflected by the specimen and that reflected by a...

A solution or combination of solutions that serves as a filter.

An immersion liquid used to treat polarizing filters to eliminate the effects of surface variations and to minimize the optical path difference between that part of the spectrum that passes through...

The pattern, formed by a character generation cathode-ray tube system, in which the characters are made up of wave shapes synthesized by a series of sine and cosine terms.

A crystalline ferroelectric material used primarily as a substrate and an active medium for thin-film optical modulators and switches. It possesses very high electro-optic and piezoelectric...

Lithium triborate (LiB3O5), commonly abbreviated as LBO, is a nonlinear optical crystal widely used in various applications involving frequency conversion of laser light. It is valued for its...

A device used to evaluate the quality of fiber optic splices made in the field by injecting light into the cladding of the fiber and measuring the output at the other end of the splice.

A device designed to convert linear change in the light state at input to log data at output.

A long-pass filter is an optical filter that allows longer wavelengths of light to pass through while blocking or attenuating shorter wavelengths. These filters are designed to transmit light with a...

A filter that is transparent to longer wavelengths but opaque to shorter wavelengths.

In fiber optic communications systems, generally one that operates between 1000 and 1700 nm.

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,...

An interference microscope that uses a light beam originating from a low-coherence light source. The sample is placed in one interferometer arm, and the other arm provides a reference beam. The...

In digital image processing, a method of convolution that reduces random noise by replacing the value of each pixel with the average of that pixel plus its neighbors, or of the neighbors alone. Also...

The analysis of structural and molecular dynamics caused by low temperature.

A type of photometer calibrated in luminance units (candles per square unit, or lamberts). In photography an exposure meter contains a luminance meter to record the average luminance of a scene.

Luminous flux emitted by a source in a given range of directions; the unit of measure is the lumen/steradian, now known as the candela.

A high-resolution spectroscopic device commonly used in the early 20th century as a component of double-beam interferometers. Light introduced at one end of the plane-parallel glass plate will be...

An illuminometer designed to measure illumination in terms of luxes.

A lymphocyte is a type of white blood cell (leukocyte) that plays a central role in the immune system. Lymphocytes are produced in the bone marrow and mature in the lymphoid organs, such as the...

A type of filter consisting of a series of birefringent crystals and polarizers invented by French astronomer Bernard Lyot for isolating and observing significant wavelengths of solar light.

A Mach-Zehnder interferometer is an optical device used to measure the phase difference between two collimated beams of light. It is named after the physicists Ludwig Mach and Ludwig Zehnder, who...

A machine vision system is an integrated combination of hardware and software components designed to capture, process, and analyze images to perform automated inspection, measurement, and quality...

The small central portion of the human retina that is responsible for providing the clearest, and most distinct aspects of human vision. Light from an object directly forms an image on the macula...

A complicated constant linked with the electron theory of the Faraday and Kerr effect. It demonstrates a specific value for each metal.

A type of high-speed photographic shutter that uses Faraday rotation to produce exposure times as fast as 1 microsecond. It consists of two polarizers, set with their planes of polarization at right...

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...

A variation from standard physical vapor deposition (PVD) coating techniques, magnetron sputtering is a plasma coating process that utilizes magnetic fields to contain the plasma in front of the...

A means of testing optical fiber for macrobending losses by wrapping the fiber once at very low tension around a mandrel, and then measuring attenuation vs. wavelength.

A device used to measure the pressure of gases and vapors, without regard to atmospheric pressure.

A wedge-shaped piece of quartz typically found in a polarimeter to monitor and rotate the plane of polarization of plane polarized light. A Martens wedge can also be used in combination with other...

A specific method for measuring the diameter of irregular shaped particles, Martin's diameter is the measured distance between opposite sides of a particle, and is measured transverse to the particle...

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...

A device used to measure the masses and relative concentrations of atoms and molecules. It utilizes the Lorentz force generated by external magnetic field on a moving charged particle, in which the...