media 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.

MCF

mutual 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.

MCM

modulation 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.

measuring eyepiece

Also 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 wedge

A 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 birefringence

Birefringence of materials that is induced or altered by stress fields.

median filtering

In image processing, a method of local smoothing by replacing each pixel with the median gray level of neighboring pixels.

MEL

many-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.

MEMS fiber optic switch

A 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...

mensuration

The process or act of measuring the geometric properties of an object or image.

metabolic imaging

Metabolic 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...

metal component

An 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...

metalens

A 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...

metamaterial

Metamaterials 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...