5,268 terms
Photonics Dictionary
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Marx generatorHigh-voltage, fast-discharge circuit named after its inventor, Erwin Marx. Its capacitors are charged in parallel and discharged in series. The voltage multiplication achieved with a Marx circuit is...
masermicrowave amplification by stimulated emission of radiation
maserA maser (microwave amplification by stimulated emission of radiation) is a device that produces coherent electromagnetic radiation in the microwave frequency range. It is the microwave analog of a...
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...
mask proximity correctionA technique used in photolithography of computer chips to compensate for errors caused by the proximity effect, which results in variations in size between areas of the mask that have many small...
mask spectrometerInstrument 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...
maskingIn image processing, the assigning of certain portions (or pixels) of an image a constant value of either 0 (black) or 1 (white) as to restrict image processing operations to a specific set of pixels...
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...
mass spectrometryMass spectrometry (MS) is an analytical technique used to determine the molecular composition and structure of compounds based on their mass-to-charge ratio (m/z). It involves ionizing chemical...
mass spectrumA spectrum that displays the distribution in mass or in mass-to-charge ratio of ionized atoms, molecules or molecular parts. Mass spectrums are typically recorded by instruments utilized in mass...
master oscillation -> injection seedingThe use of a small ultrastable master oscillator (a diode-pumped Nd:YAG laser) to achieve single-frequency operation of a large pulsed Nd:YAG host laser, providing improved bandwidth and temporal...
matchThe condition of identity of visual appearance.
matched transmission lineA transmission line having no wave reflection along its path.
material dispersionThe dispersion attributable to the wavelength dependence of the refractive index of the material used in any optical application.
matrixWith respect to television, that part of a color television circuit that combines the I, Q and Y signals, and changes them into single red, green and blue signals applied to the picture-tube grids.
matrix arrayImage sensors in a two-dimensional configuration of rows or columns.
Matrix opticsThe linear relationship between input and output optical fields for a given optical system or application that allows the use of a matrix and matrix algebra to define an optical system, or series of...
matrix-assisted laser desorption/ionizationProcess of analysis in which the analyte substance is distributed in a matrix before laser desorption. This method avoids the mass limitations associated with laser desorption and possibly enhances...
mattA term used to describe a nondirectionally diffusing surface that, when illuminated, appears equally bright from all angles. An example of this kind of surface is the screen used for the forward...
MAUmedia access unit — A media access unit (MAU) is a unique device utilized to connect token ring devices from multiple network stations into a star topology. There are two types of MAUs, passive and active. Passive MAUs are powered from their network connections while active MAUs are powered electrically from an external source.
maximum permissable exposureThe maximum level of laser radiation that a person may be exposed to without adverse biological effects.
maximum saturationThe highest value of saturation possible for a specified hue.
Maxwell triangleA diagram used to represent the trichromatic variables of the components in a three-color combination.
Mbmegabit — The megabit (also expressed as Mbit) is equivalent to one million (or 106) of the standard unit for digital information storage in telecommunications which is the bit.
MBmegabyte — The megabyte (also expressed as Mbyte) is equivalent to one million (106) of the standard unit for digital information storage in computing which is the byte.
MB/smegabytes per second — The megabyte per second (not to be mixed up with the Mb/s -- megabits per second) is a unit of data transfer rate equivalent to one million (106) bytes per second over a given information network.
Mb/smegabits per second — The megabit per second (not to be mixed up with the mbit/s – millibit per second, or Mbitps- megabit picosecond) is a unit of data transfer rate equivalent to one million (or 106) bits per second over a given information network.
MBEmolecular beam epitaxy — A well-controlled thin film technique for growing films with good crystal structure in ultra high vacuum environments at very low deposition rates. MBE is also commonly used in the manufacture of semiconductor devices and solar cells.
Mc/smegacycles per second — Megacyces per second is an oscillation rate equivalent to one million (or 106) of the standard unit of a single optical period over a second which is an optical cycle.
McClatchey modelCalculation of gas and aerosol transmission and emission characteristics for several model atmospheres, including two model aerosol distributions.
mcdmillicandela — The millicandela is equivalent to one thousandth (or 10-3) of the standard unit of luminous intensity that is the candela, which is the power emitted by a given light source in a particular direction.
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.
MCMmodulation contrast microscopy; multichip module — modulation contrast microscopy is a unique illumination technique that enhances contrast in an imaging microscope by converting optical gradients into variations in light intensity. Modulation contrast microscopy is found most commonly in live cell imaging, polarization microscopy, phase contrast, and oblique illumination of stained, unstained and birefringent specimens. A multichip module is an electronic packaging system where multiple discrete electronic components (integrated circuits, semiconductor diodes, etc.) are packaged in various ways onto a single substrate.
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.
MCVDmodified chemical vapor deposition
MCZmagnetic Czochralski process — Introduction of an external magnetic field in the Czochralski melting process for crystal growth in order to influence the flow and dampen the amplitudes of the melt oscillations that occur in the process. This is accomplished when the external magnetic field generates an electric field inside the melt, which further induces an internal magnetic field in the now electrically conducting melt. The amplitudes of the now induced electric and magnetic fields can be controlled by the strength of the external magnetic field allowing control of the MCZ process.
MDLminimum detection limit (MDL) — In chemistry, the minimum detection limit is the lowest concentration of a chemical substance that can be discerned from the absence of that substance.
mean dispersion -> dispersive powerA measure of the dispersive properties of a glass. The relative dispersion is defined as:
where C, D, and F refer to the material's index of refraction at the three chief Fraunhofer lines in the...
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...
mean spherical intensityThe average intensity of a light source measured over all directions.
mean spherical luminous intensityThe average luminous intensity of a point light source measured over all directions.
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...
measuring wedgeA wedge in a rangefinder or heightfinder used to displace the image produced by one telescope so that it coincides with that produced by the other telescope, thus affording a measurement of the...
mechanical spliceA fiber splice accomplished by fixtures or materials, rather than by thermal fusion. Index matching material may be applied between the two fiber ends.
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...
mediumAny substance or space through which electromagnetic radiation can travel.
megaIn the SI system, prefix meaning 1 million, 106.
Meissner effectThe elimination of magnetic fields from within a material as that material makes the transition from the normal to superconducting state.
MELmany-element laser; maximum excess loss (MEL) — the many element laser is a laser unit that consists of N like elements of active materials for support with the mode selection of the laser output. The mode selection properties of a many element laser have been experimentally exploited with as many as 10 like elements.
Maximum excess loss is the maximum power lost within a give system (typically a fiber optic communication system) including scattering, dispersion, absorption and coupling loss.
Photonics Dictionary