8,726 terms
Photonics Dictionary
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.
Mcmegacycles
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.
MCAmicrochannel analyzer
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.
McLeod gaugeA gauge designed to measure high degrees of vacuum. It consists of a glass bulb attached to the vacuum vessel, the measurement being made by filling the bulb with mercury and observing the volume of...
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.
MCPmicrochannel plate
Mcpsmegacycles per second
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.
MDMmetal-dielectric multilayer (MDM) — Periodic nanofilm structures for optical mode confinement and tunneling of resonant surface plasmons.
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 birefringence -> stress birefringenceBirefringence of materials that is induced or altered by stress fields.
mechanical center -> geometric centerThe physical center of the lens; it is on the axis of the lens, halfway between the front and rear vertex. It is sometimes referred to as the mechanical center of the lens.
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.
mechanical tube lengthIn a microscope, the physical distance between the focal points of the objective lens and the eyepiece. The standard tube length for a microscope is typically 160 mm).
medmedium
median filteringIn image processing, a method of local smoothing by replacing each pixel with the median gray level of neighboring pixels.
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.
melting pointThe temperature at which the solid phase of a material is in equilibrium with the liquid phase, or when the material changes from a solid to a liquid.
memberIn a lens system, a group of elements considered as an entity; either a front or rear member depending on whether it is before or after the aperture stop.
MEMS -> microelectromechanical systemsRefers 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.
MEMSmicroelectromechanical systems
MEMS fiber optic switchA MEMS fiber optic switch is a microelectromechanical system (MEMS) device designed to selectively route optical signals between multiple fiber optic channels. These switches utilize miniature...
meniscus anastigmatAn anastigmatic lens with a thick meniscus construction that flattens the field and corrects chromatic and spherical aberration.
meniscus lensA meniscus lens is an optical lens that has one side that is concave (curved inward) and the other side that is convex (curved outward). It can be categorized into two types based on its optical...
mensurationThe process or act of measuring the geometric properties of an object or image.
MERAmolecular electronics for radar applications
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...
meridional planeThat plane in an optical system containing its optical axis and the chief ray. Also called the tangential plane.
meridional rayA ray that lies in the meridional plane; a ray that lies in the plane that contains the optical axis. A tangential ray.
merit function -> error functionA single number, defined by the computer program or the user that expresses the performance of an optical system. Also known as merit function and defect function, the error function comprises...
meso formA form of an element that cannot demonstrate optical activity as a result of dextrogyrate and levogyrate effects that are balanced contrary to each other in a structure. In essence, meso form...
mesopic visionVision at intermediate levels of luminance between photopic and scotopic vision, where both retinal cones and retinal rods are stimulated for visual use in dim, low light situations. See also...
mesoscopeIn the field of optics and imaging, a mesoscope refers to an optical instrument that is designed to observe and capture images at intermediate scales, falling between microscopic and macroscopic...
Photonics Dictionary