69 terms
Photonics Dictionary: M
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monitor currentIn a laser diode, the photocurrent produced by a photodiode that detects the emission from the rear facet of the semiconductor chip. It can be used to provide feedback control of the forward current...
mutual coherent functionA function that quantifies the performance degradation of coherent communications systems, imaging systems and all systems that rely on the spot size of a laser beam that has propagated along an...
multimode group delay -> differential mode delayA variation in propagation delay caused by differences in group velocity among modes of an optical fiber. Also called multimode group delay, this effect is commonly due to imperfections or any...
mAmilliampere (or milliamp in English) which represents one thousandth, i.e. 10-3, of the SI unit for electric current that is the ampere (also commonly referred to as amp).
Mach-Zehnder interferometerA 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...
machine vision lightingMachine vision lighting refers to the use of specific lighting techniques and equipment in the field of machine vision, which is a technology that enables machines to capture and interpret visual...
magnetic lensAn arranged series of coils, magnets or electromagnets disposed in such a way that the resulting magnetic fields generate a Lorentz force that is used to then focus or deflect beams of rapidly moving...
magnetic spectrographAn electron system using the effect of a constant magnetic field on electron paths to differentiate electrons that have varying velocities for the accurate measurement of the energies and intensities...
magneto-optic shutterA 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...
magnetometerA 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...
magnificationThe ratio of the size of the image of an object to that of the object. The ratio of the linear size of the image to that of the object is lateral magnification. Angular magnification is the ratio of...
magnifying powerThe ability of an optical system to make an object appear larger. An optical element or optical system causing an object to appear twice as high and twice as wide is said to have a magnification of...
magnonA magnon is a quasiparticle representing a quantized spin wave in a magnetic material. In other words, it is a collective excitation of the spins of electrons in a magnetic solid, analogous to the...
majorA blank to which a piece of glass of a different refractive index will be fused to form a multifocal lens.
mAsmilliamperes-second - unit measure of electric charge acquired when multiplying the electric current in milliamperes (one thousandth or 10-3 of the standard unit for electric current the ampere) by the time in seconds. It is commonly used to describe the length of time that electrons are produced or passed through a given circuitry.
maserAn acronym for microwave amplification by stimulated emission of radiation. Predecessor to the laser, the maser or 'microwave laser' was the first device to produce coherent electromagnetic waves,...
mask1. A framelike structure that serves to restrict the viewing area of the screen when placed before a television picture tube.
2. In photolithography, a photomask (or mask) is typically a patterned...
masks for evaporation/depositionIn the context of thin film deposition processes such as evaporation or sputtering, masks are used to selectively deposit material onto substrates, creating patterns or structures with precise...
mass spectrometerA 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...
MCFmutual coherence function — The mutual coherence function is a complex quantity that is the time-averaged value of the cross correlation function of a light field at two points within an aperture with a time delay that relates the path difference to the point of observation of the interference fringes. The mutual coherence function is the key function in coherence theory and the study of partially coherent light.
MCTmercury cadmium telluride — Mercury cadmium teluride (HgCdTe) is a specific alloy combination that allows one to obtain any optical absorption bandgap of the material between 0 and 1.5 electron volts (eV) making it completely transparent at photon energies and wavelengths below the energy gap in the infrared.
mean solar timeOne of two types of solar time - the other being apparent solar time - the mean solar time is the time measured by the average hour angle position of the sun in the sky compiled over a period of one...
measuring eyepieceAlso known as an eyepiece micrometer. A microscope eyepiece that has a finely divided scale ruled or photographed on a section of transparent glass, and located in the focal plane. The dimensions of...
medical lasersMedical lasers are devices that produce intense beams of light with specific characteristics and properties, which are used for various medical applications. These lasers emit light in the form of...
mercury arcAn electric arc that is formed in mercury vapor through which an electric current flows. The intensity of the illumination of the arc depends mostly on its design and the conditions under which it...
mercury vapor light sourceA lamp that has mercury in a tube or bulb that has first been evacuated. The electricity travels through the vapor between the electrodes and produces a blue-green light that is rich in ultraviolet...
metal componentAn accurate metal prism or plane parallel plate that is cemented to an optical element and remains with it during a series of grinding or polishing processes. The metal element contains threaded...
metalensA metalens, short for "metasurface lens," is a type of optical lens that uses nanostructured materials to manipulate light at a subwavelength scale. Unlike traditional lenses made of glass or other...
metameric matchVisual equivalence of physically (usually spectrally) different stimuli.
metamerismIn 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...
metaverseThe 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...
Michelson-Morley experimentAn 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...
microbubble resonatorA 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")...
microchannel spatial light modulatorA 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...
microinterferometer -> interference microscopeA special form of microscope that utilizes interference for observing and measuring the phase and optical thickness in completely transparent objects and specimen. The object is placed in one beam...
microphotonicsThe 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...
microRNAMicroRNAs (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....
microwave holographyThe 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...
mid-infrared cameraA mid-infrared camera is a type of imaging device designed to capture images in the mid-infrared (mid-IR) spectral range, typically spanning wavelengths from approximately 3 to 12 µm. This...
mid-wave infraredMWIR stands for mid-wave infrared, referring to a specific range of wavelengths within the infrared spectrum. Infrared radiation is categorized into three main regions based on wavelength:...
Mie scatteringMie scattering, named after the German physicist Gustav Mie, refers to the scattering of electromagnetic radiation (such as light) by spherical particles. Unlike Rayleigh scattering, which is...
minimum object distanceMinimum object distance, often abbreviated as MOD, refers to the closest distance at which a camera lens or optical system is capable of producing a sharp and focused image. In photography, this term...
mirror lensAn image-forming system having curved mirrors in place of transparent glass components. Mirror lenses are commonly used for astronomical purposes as well as cheap solutions for very long focal length...
mixed-signal oscilloscopeA mixed-signal oscilloscope (MSO) is a type of electronic test instrument that combines the capabilities of both a traditional oscilloscope and a logic analyzer. It is designed to capture and display...
mode beatingIn optics, "mode beating" refers to an interference phenomenon that can occur in laser systems with multiple longitudinal modes. Longitudinal modes are specific electromagnetic field patterns that...
mode distortion -> multimode distortionIn an optical waveguide,- typically a multimode fiber - the distortion resulting from differential mode delay, i.e. axial rays (modes), with the shortest path length, will have the shortest...
mode hoppingMode hopping in the context of lasers refers to a phenomenon where a laser system abruptly switches from one longitudinal mode to another. In a laser, different longitudinal modes represent distinct...
mode-locked lasersMode-locking is a technique used in lasers to produce ultrashort pulses of light with durations on the order of picoseconds, femtoseconds, or even attoseconds. This method synchronizes the phases of...
modified chemical vapor depositionModified chemical vapor deposition (MCVD) is a technique used in the fabrication of optical fibers. It is a specialized form of chemical vapor deposition (CVD) that is employed to produce...
modulation transfer function analysis/measurement equipmentMTF analysis/measurement equipment refers to instruments and tools used to measure and analyze the modulation transfer function (MTF) of optical systems. The MTF is a quantitative measure of the...
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