Photonics Dictionary

A measuring device that uses a light-sensitive cell or detector to determine the amount of light transmitted by a substance.

An atomic clock is a highly precise timekeeping device that uses the vibrations or oscillations of atoms as a reference for measuring time. The most common type of atomic clock uses the vibrations of...

Beam profiling is a technique used to characterize and analyze the spatial intensity distribution of a laser beam. It involves measuring and visualizing how the optical power or intensity is...

Calorimetry is a branch of science that involves the measurement of heat flow in physical or chemical processes. It encompasses various techniques and instruments used to quantify heat transfer,...

An instrument for measuring the vertical angle of an object. It usually contains an accurately made protractor, a sensitive level bubble, and a sighting device, such as a small telescope.

1. A device used in chemistry to compare the colors of solutions held in flat-bottomed tubes and viewed along the length of the tube. Often a solid glass plunger is moved along one of the tubes to...

A fiber optic spectrometer is a device used for measuring the spectral content of light. It utilizes optical fibers to transmit light from a source to a spectrometer unit, where the light is...

A method of measuring flow velocity by seeding the flow with neutrally buoyant particles and using a pulsed laser to holographically record particle displacement during a short time period. An...

An infrared light-emitting diode (IR LED) is a semiconductor device that emits infrared light when an electric current passes through it. Similar to standard LEDs that emit visible light, IR LEDs are...

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...

A laser rangefinder is a device that uses laser technology to measure the distance between the device and a target. It operates on the principle of measuring the time it takes for a laser beam to...

A lateral shearing interferometer is an optical device used in interferometry to measure phase differences between two beams of light. Interferometry is a technique that combines and analyzes...

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 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...

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,...

A device used in measuring the attenuation of multimode optical fibers. A short reference length of fiber when combined with the mode filter has approximately the same angular output distribution of...

A measurement technique used to determine the spatial distribution profile of an electrical or optical quantity of interest which is provided by multiple scans within the near-field region of a...

A pollution-measuring device used to detect the presence of nitric oxide regardless of other gases present. It utilizes the principle of laser magnetic resonance (LMR).

An optical assembly refers to a collection of optical components that are carefully arranged and aligned to perform a specific function within an optical system. These components may include lenses,...

A device for measuring linear dimensions. The optical caliper generally consists of two circularly mounted mirrors whose angular positions are monitored by an autocollimator, and that are capable of...

An optical channel monitor (OCM) is a device used in optical communication systems to monitor and analyze the performance of individual channels within a wavelength-division multiplexing (WDM)...

A device for measuring diffraction grating efficiency at any angle of incidence, consisting of a reflectometer wherein the detector rotates around the grating at a specific distance and is attached...

Optical manufacturing tools and machinery encompass a wide range of equipment, instruments, and systems used in the fabrication, shaping, finishing, and testing of optical components and systems....

Optical strain sensors are devices that utilize optical principles to measure the deformation or strain experienced by a material under mechanical stress. These sensors convert changes in strain into...

An optical testing instrument is a device or system used to evaluate and measure the performance, quality, and characteristics of optical components, systems, and devices. These instruments play a...

A device for measuring absorption coefficients in which a confined, nonabsorbing gas fills the space inside the cell between the two windows, which are made from a weakly absorbing medium.

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...

A quantum cascade laser (QCL) is a type of semiconductor laser that operates based on the principles of quantum mechanics. It is a versatile and powerful device used for emitting coherent light in...

Quantum-enhanced metrology refers to the use of quantum mechanics principles and techniques to enhance the precision and sensitivity of measurements in metrology—the science of measurement....

A device used in measuring attenuation in optical fiber. The loss caused by the bends in a short reference length of fiber approximates that of a much longer fiber under test.

The Shack-Hartmann wavefront sensor is an optical device used for measuring the wavefront aberrations of an optical system. It is widely used in adaptive optics systems to correct distortions and...

A silicon photodiode is a semiconductor device that converts light into an electrical current. It is a type of photodetector specifically designed for detecting and measuring light intensity. Silicon...

Ultrasonic refers to sound waves with frequencies higher than the upper audible limit of human hearing, typically above 20,000 Hz. These waves are termed ultrasonic because they are beyond the range...

A device that calibrates the size, position or distance of objects imaged on a video screen.