Photonics Dictionary

Metamaterials are artificial materials engineered to have properties not found in naturally occurring substances. These materials are designed to manipulate electromagnetic waves in ways that are not...

Metaphotonics is an emerging field at the intersection of photonics, metamaterials, and nanotechnology. It involves the design, fabrication, and study of metamaterial-based optical structures and...

An excited energy state of an atom or atomic system that has a longer lifetime than the ordinary excited state and typically a shorter lifetime than the ground state of that system. Metastable states...

Metasurfaces are two-dimensional arrays of subwavelength-scale artificial structures, often referred to as meta-atoms or meta-elements, arranged in a specific pattern to manipulate the propagation of...

The photographic recording of objects or events in a manner that allows quantitative information to be derived from the photograph. An example is the film made by a cinetheodolite in photographing a...

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...

An optical experiment carried out conclusively in 1887 that demonstrated that the ether, a hypothetical medium postulated by physicists to explain how light could travel in a wave motion through...

Micro-LED (micro-light-emitting diode) refers to a technology that involves the use of very small light-emitting diodes to create displays and lighting systems. These LEDs are miniature versions of...

Micro-optical coherence tomography (micro-OCT) is an imaging technique that is an adaptation of optical coherence tomography (OCT) to achieve high-resolution, cross-sectional imaging of biological...

Micro-optics refers to the design, fabrication, and application of optical components and systems at a microscale level. These components are miniaturized optical elements that manipulate light at a...

A micro-ring resonator is a compact optical device that utilizes the resonant behavior of light within a small ring-shaped waveguide structure to selectively enhance or filter certain wavelengths of...

Micro-robotics refers to the field of robotics that involves the design, development, and application of miniature robotic systems, often at the microscale. These robots, commonly referred to as...

In optical fiber, sharp but microscopic curvatures that create local axial displacements of a few microns and spatial wavelength displacements of a few millimeters. One frequent cause is longitudinal...

A microbubble resonator is a device used in photonics and optical physics for the precise manipulation of light waves. It consists of a micro-sized, gas-filled spherical cavity (the "microbubble")...

A method of heat removal in which liquid passes through small channels with high packing densities.

A microchannel plate (MCP) is a specialized electron multiplier device used in various applications such as particle detection, imaging, spectroscopy, and night vision technology. It consists of a...

A device to modulate spatially a collimated coherent beam of light with input data in optical data processing. It uses a photocathode mounted on a microchannel plate, which amplifies an electron...

The formation of transistors, diodes, capacitors, resistors and other electronic elements directly on a flake of silicon by etching and selective absorption of doping elements. A circuit diagram...

A microcircuit typically refers to an integrated circuit (IC) or chip that contains miniaturized electronic components, such as transistors, resistors, capacitors, and diodes, fabricated on a small...

A microcomb, short for microresonator frequency comb, is a novel photonic device that generates a precise series of evenly spaced optical frequencies, akin to the teeth of a comb, across a broad...

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...

Microelectromechanical systems, or MEMS, refer to miniature devices or systems that integrate mechanical and electrical components at a microscale. These systems combine elements such as sensors,...

A small card (10 x 15 cm) that has been treated with a photographic emulsion to record and store the microimages of documents and graphic information projected on it by a microfilm camera. A...

A camera used to reduce originals onto film for easy storage. There are two basic types: one in which the film is fixed during exposure, and one in which the film is exposed while moving past an...

Two essential pieces of equipment used in connection with the microfilming process: a camera capable of producing, on film, large-scale reductions of almost any matter, printed, painted or...

An extremely short, high intensity electronic flash of light, having a duration of about 1 x 10-6 s, used in photographing rapidly moving subjects.

Microfluidics is a multidisciplinary field that involves the manipulation and control of very small fluid volumes, typically in the microliter (10-6 liters) to picoliter (10-12 liters) range, within...

Extremely small organic and inorganic systems of molecules within a substance. In general, systems are colloidal size in spite of the large number of molecules. Photochemistry and optical...

A hologram having an image scale that is orders of magnitude smaller than microfiche images.

A microlens array is a grid-like structure composed of numerous small lenses, typically arranged in a regular pattern. Each individual lens in the array is referred to as a microlens. These...

A technique for producing micron-size structures on surfaces by using short-wavelength light or electron beams.

Output noise in a laser beam resulting from acoustic disturbances of mirror separation or orientation. Such disturbances may come either from the plasma or from vibration of external sources.

The formation of microimages for microreduction. The technique is used, for example, in the production of precision reticles or resolution charts. The sensitized materials used in the process must...

A photograph reduced to the microscopic scale and stored on a microfilm as seen with microfiches for the purpose of storing and archiving information.

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...

The measurement of the intensity of spectral lines by the examination of a very small area under a microscope and the measurement of the density at any point of the image.

The technology of manipulating light on a micro scale. In optical communications, this is usually accomplished using two or more materials with significantly different indicies of refraction. In most...

A laser-induced scar on experimental bare glass surfaces usually attributable to threshold damage and indicative of isolated damage-susceptible areas in the glass.

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...

MicroRNAs (miRNAs) are a class of small, single-stranded RNA molecules, typically consisting of about 19 to 24 nucleotides, that play important roles in the regulation of gene expression in cells....

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...

An eyepiece located at the near end of the microscope tube. It often is a simple Huygens eyepiece, but compensating and flat-field projection eyepieces are quite efficient. Negative eyepieces are...

A specialized spectrophotometer for use through a microscope on very small areas of an object.

Microscopic investigation of two-dimensional areas of a three-dimensional object that can be quantitatively evaluated by consideration of the line intersections or point counts obtained via...

An electromagnetic wave lying within the region of the frequency spectrum that is between about 1000 MHz (1 GHz) and 100,000 MHz (100 GHz). This is equivalent to the wavelength spectrum that is...

The holographic recording of the pattern formed by two sets of coherent microwaves that interfere at a scanning plane. A scanning device converts the microwave interference pattern into a light...