Definitions: M

In colorimetry, the phenomenon in which spectrally different radiations produce the same color sensation for a given observer. In chemistry, the chemical property of two elements or molecules sharing...

A sensing or image-forming detector that serves to convert infrared rays into visible signals for communication purposes. Also, a form of telescope that generates visible images on a fluorescent...

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 term "metaverse" refers to a collective virtual shared space, created by the convergence of virtually enhanced physical reality and persistent virtual worlds. It is a concept derived from science...

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,...

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...

A cable backbone used to interconnect local area networks at various sites (corporate offices and factories, for example) in a given region. Optical fiber is well-suited to the transmission of both...

An interferometer constructed to be positioned on a telescope to measure the angular separation of the components of double stars.

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...

Process developed for the production of high-resolution patterns in electro- and magneto-optics. These high-generation devices use ion beams and plasma-free radicals.

In the SI system, prefix meaning one-millionth, 10-6. Abbreviated µ.

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...

A thin-film device that integrates optics and electronics on a single chip to provide a passive-ring resonator gyroscope capable of withstanding high g forces.

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...

A small opening or slit in a mask.

A type of fiber optic sensor that detects changes in pressure, vibration, sound level or acceleration by monitoring the ejection of light from the fiber core to the cladding caused by microbending...

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...

Transmission loss in optical fibers caused by packaging processes; it is considered a power-coupling effect from the guided modes to the radiation modes.

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...

A microscopic crystal found in an intricately crystallized substance that is only visible under a microscope.

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...

The science that deals with the measurement of optical absorbance (i.e. optical densities) over microscopic areas of a given specimen or optical material.

A microdisplay is a miniature electronic display technology that is designed to project visual information onto a small screen. Unlike traditional displays, microdisplays are typically very compact...

Refers to micron-size complex machines that have physical dimensions suitable for the fabrication of optical switches for use in state-of-the-art communications networks.

Equipment that supports microscopic live-cell imaging by managing the gas, media perfusion, temperature and other factors to which a sample is exposed. While reducing the negative impacts these...

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...

A device used to view microfilmed documents where the image on film is projected, in magnified form, onto a rear projection screen for viewing.

A camera copying system that can reduce originals onto 35- or 16-mm film for easy storage.

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...

A fluoroscope equipped with a magnified, fine-grained fluorescent screen to determine the fluorescence emitted by a microscopic source.

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.

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...