8,617 terms
Photonics Dictionary
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...
mesosphere -> chemosphereAlso known as mesosphere. A level of the atmosphere, extending from the stratosphere to the ionosphere, that is noted for its photochemical activity.
meta-opticsMeta-optics, also known as metasurface optics or flat optics, is a branch of optics that involves the design, fabrication, and utilization of artificial structures called metasurfaces to control and...
metabolic imagingMetabolic imaging refers to the visualization and quantification of metabolic processes within living organisms, tissues, or cells using various imaging techniques. It provides insights into the...
metaboliteA metabolite is any small molecule that is a product of metabolism, the chemical processes that occur within living organisms to maintain life. Metabolites can include a wide variety of molecules,...
metal arcThe electrical arc formed between metal rods that emits the spectrum of the metal itself. Commonly used in the chemical analysis of metals.
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...
metal vapor laserDevices in which the lasing medium is a vapor of metal atoms or ions, sometimes mixed with another gas. Metal vapor lasers use a variety of metal types to generate a variety of laser lines for...
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...
metallic coatingA thin layer of metal deposited on the surface of a substrate. The film may serve as a reflector, beamsplitter, neutral density filter or electromagnetic interference filter.
metallic mesh filterAn interference filter in which a very thin metal foil with a periodic array of square holes (inductive mesh) or a thin plastic substrate with an array of metal squares (capacitative mesh) is used as...
metallographic microscopeA specially designed microscope for observing the etched surface of a polished metal specimen. The specimen is often laid face down on a horizontal stage and observed from beneath, the illumination...
metallographic polishing machineA small optical polishing machine intended for polishing the surface of a metal specimen before etching for examination under a microscope. Although shaping and polishing machines for this purpose...
Photonics Dictionary