Photonics Dictionary: M

A 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...

A method used to detect internal or residual microstresses in a material by using a laser beam to locate changes in polarization caused by the stress.

A zone plate produced by a computer and having a binary structure that can be etched into a chromium or quartz layer. It often is used in laser machining, in which the machining of small holes with...

In general, changes in one oscillation signal caused by another, such as amplitude or frequency modulation in radio which can be done mechanically or intrinsically with another signal. In optics the...

Rate at which optical radiation or a signal is varied through the use of a mechanical or electronic chopper. Also called chopping frequency.

A method of spectral analysis in which some property of the sample is varied and the corresponding change is measured. The change is induced by a repetitive perturbation such as an electric field,...

Also called sine wave response and contrast transfer function. The modulation transfer function is the ratio of the modulation in the image to the modulation in the object as a function of frequency...

A modulator is a device or component that modifies a carrier signal in order to encode information for transmission over a communication channel. The process of modulating involves varying one or...

The resulting interference pattern generated from moiré deflectometry, the moiré pattern is a pattern developed from interference or light blocking, when gratings, screens or regularly...

A blank whose basic surface curves are attained by heating and forming a given weight of raw glass; a rough glass blank resembling the finished lens in size and shape. After molding, a precision lens...

A molded lens is an optical lens manufactured using a molding process, typically involving the shaping of a material, such as glass or plastic, into the desired lens shape. This process involves...

A molecular motor refers to a nano-sized device composed of organic molecules or other small-scale components that can convert light energy into mechanical motion at the molecular level. These...

Spectrum analysis concerned with the spectra formed by transitions in molecules.

Graphic evaluation of the operation of a steam thermodynamic cycle of a solar energy system on which enthalpy is plotted against entropy.

Light consisting of a single wavelength or a very narrow band of wavelengths.

A monochromator is an optical instrument used to isolate and select a narrow range of wavelengths from a broader spectrum of light. The term monochromator is derived from "monochromatic," meaning...

An array of refractive microlenses that are round, square and hexagonal and as small as 15 µm. They are used for Hartmann testing, laser diode collimation and other applications that require...

A character generation CRT that functions on the principle of secondary emission. The target holds a set of aluminum characters, select characters being scanned by the electron beam. The secondary...

Simulation of radiative transfer in which each photon is generated by a source and its path through the medium is statistically simulated with absorption and scattering probabilities as well as with...

A set of algorithms used to study the structural and spatial characteristics of objects in a digitized image for applications including feature extraction and image segmentation in machine vision and...

A group of photosensors arranged in a grid-like pattern covering the entire field of view, enabling them to record it all at once (as a camera records an image on film) rather than by scanning parts...

In optics, a motion controller refers to a device or system that precisely controls the movement of optical components, such as mirrors, lenses, stages, or other elements within an optical setup. The...

A camera equipped with a lens and a long length of perforated film, the latter being moved intermittently between exposures by a pulldown claw or sprocket. A rotating shutter serves to cut off the...

A metal-semiconductor-metal (MSM) photodiode is a type of photodetector that consists of metal electrodes on a semiconductor material. Unlike the more common PIN photodiodes, which have a P-type and...

Multi-axis alignment refers to the process of aligning or adjusting components or systems in multiple spatial dimensions or axes. In various technical and engineering contexts, achieving precise...

A photon-counting instrument for use in both space-borne and ground-based photometric and spectroscopic instrumentation. This style of detector is composed of opaque photocathodes for photon to...

A group of four cameras loaded with different combinations of filters and film (one is usually an infrared color film) to permit the recording of the same subject in four separate regions of the...

A hologram formed by reconstruction of multicolor wavefronts. The system used to produce the hologram is designed to combine the different colored wavefronts of the separate illuminating sources, and...

Fiber optic cable bearing many fibers independently sheathed and capable of carrying unrelated signals. They often surround a central strength member, and can be either loose- or tight-buffered. One...

An array of optically distinct fibers that are fused into one strand. They are used to keep the resolution efficiency of the smaller, single fibers and eliminate difficulty in handling. Their...

A lens with internally adjustable elements to produce a range of focal lengths. Unlike a true zoom lens, a multifocal lens must be refocused each time the focal length is changed. See variable-focus...

A photovoltaic device that consists of multiple p-n junctions to produce a greater efficiency when in use than that of traditional single junction devices. A multijunction device is unique because...

A 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...

A fiber optic bundle split along its length with the ends of the fibers extending separately to illuminate different points with a single light source.

A multiline laser system refers to a type of laser that is capable of emitting multiple discrete wavelengths or spectral lines simultaneously. Unlike single-line lasers, which produce radiation at a...

A technique that combines two or more imaging processes in order to minimize the disadvantages within each of the contributing processes. In medical applications, combining multiple modalities...

In an optical waveguide,- typically a multimode fiber - the distortion resulting from differential mode delay, i.e. axial rays (modes), with the shortest path length, will have the shortest...

A laser that produces emission in two or more transverse or longitudinal modes.

A method of reducing dark current in charge-coupled devices by holding all the clocks at negative voltage during the integration period.

Characteristic of optical correlators in which invariance to more than one distortion parameter per axis of the processor is obtainable.

A camera that uses a rotating mirror to project sequential images onto lenses that are arranged in an arc. The reflected images can then be recorded on stationary film. By using an 8-mm frame format,...

A specific form of phase shifting interferometry - commonly referred to as multiple wavelength phase shifting interferometry - this form of interferometry utilizes two short wavelengths to synthesize...

The recording and mathematical analysis of all spectral intervals of the spectrometer simultaneously.

The combination of two or more signals for transmission along a single wire, path or carrier. In most optical communication systems this is referred to as wavelength division multiplexing, in which...