137 terms
Photonics Dictionary: M
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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...
Martin's diameterA specific method for measuring the diameter of irregular shaped particles, Martin's diameter is the measured distance between opposite sides of a particle, and is measured transverse to the particle...
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.
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.
mirror coatingOne or more thin-film layers of optical material deposited on a mirror blank/substrate in order to enhance the way that substrate reflects light. For example of optical materials/optical coatings...
mirror testingThe observation and measurement of the flatness of a mirror surface by contacting an optical flat with the mirror. The process generally is done before coating so as not to damage the delicate coated...
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...
modulated grating hologramA computer-generated, phase-and-amplitude, off-axis hologram made by a multi-exposure technique that uses three computer generated transmission masks. Each mask controls one fixed-phase component of...
mounting cementAn adhesive used to hold optical components in their mounts. It may be a thermoplastic or chemical-hardening substance.
multilayer coatingA coating made up of many layers of material having alternating high and low refractive index. In this way, it is possible to produce coatings with a great variety of properties. These may be...
micro-LEDMicro-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...
Mach bandsThe illusory appearance of a light or dark band at a line of brightness contrast that enhances the edge between the two contrasting regions. This effect can create the appearance of graduated...
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 learningMachine learning (ML) is a subset of artificial intelligence (AI) that focuses on the development of algorithms and statistical models that enable computers to improve their performance on a specific...
machine vision lensA machine vision lens is a specialized optical lens designed for use in machine vision systems, which are used for automated inspection, measurement, and quality control in industrial applications....
machine vision systemA machine vision system is an integrated combination of hardware and software components designed to capture, process, and analyze images to perform automated inspection, measurement, and quality...
machine visionMachine vision, also known as computer vision or computer sight, refers to the technology that enables machines, typically computers, to interpret and understand visual information from the world,...
macula luteaThe small central portion of the human retina that is responsible for providing the clearest, and most distinct aspects of human vision. Light from an object directly forms an image on the macula...
magnesium fluorideA colorless, crystalline compound whose low refractive index (n = 1.38) makes it effective as a lens antireflection coating when deposited by thermal evaporation in a near vacuum. This process...
magnetic bubble filmAn amorphous film in which cylindrical bubbles of reverse magnetization can be formed to follow circuit paths usually made by depositing magnetic metal strips on the film surface. It is used in...
magnetic force microscopeA variation of the atomic force microscope that operates by scanning a tiny ferromagnetic probe (or a magnetized tip) over a magnetic sample, and detecting the extremely small forces exerted on the...
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 resonance spectroscopyA method of studying the chemical and physical properties of atoms and molecules (typically living tissue and chemical samples) by exploiting the magnetic properties of their atomic nuclei when an...
magnetic vectorA term denoting the magnitude and direction of the magnetic field associated with an electromagnetic wave when describing light in its vector form.
magneto-opticsMagneto-optics refers to the study and manipulation of the interaction between magnetic fields and light (electromagnetic radiation). This field of physics explores how the properties of light, such...
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...
magnetron sputteringA variation from standard physical vapor deposition (PVD) coating techniques, magnetron sputtering is a plasma coating process that utilizes magnetic fields to contain the plasma in front of the...
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...
Maksutov objectiveA catadioptric lens assembly consisting of a Maksutov corrector and a spherical primary mirror.
mandrel wrap testA means of testing optical fiber for macrobending losses by wrapping the fiber once at very low tension around a mandrel, and then measuring attenuation vs. wavelength.
marginal errorThe distortion in an ophthalmic lens resulting from the refraction of light rays entering the periphery of the lens surface. It increases relative to the power of the lens.
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 relievingThe removal of material from an optical system to decrease the weight and sometimes the bulk of the system. See coring; egg-crating.
material scatteringThe total scattering attributable to the intrinsic properties of the materials through which an optical wave is propagating.
Maxwell's equationsThe mathematical set of equations showing the relationship between oscillating electric and magnetic fields that are generated by an oscillating electric charge. Intrinsic to Maxwell's equations is...
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.
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.
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.
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...
Meissner effectThe elimination of magnetic fields from within a material as that material makes the transition from the normal to superconducting state.
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...
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...
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...
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...
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 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...
metamaterialMetamaterials are artificial materials engineered to have properties not found in naturally occurring substances. These materials are designed to manipulate electromagnetic waves in ways that are not...
metastable stateAn 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...
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