Photonics Dictionary

The Mills Cross telescope is a two dimensional radio telescope in which the two antenna arrays are positioned perpendicular to each other to form the shape of a cross. Each antenna consists of...

Small tungsten lamp used in surgical instruments such as cystoscopes, and for other purposes where space is limited.

The smallest angle through which light is bent by an optical element or system. In a prism, the angle of deviation is a minimum if the incident and exiting rays form equal angles with the prism...

Minimum object distance, often abbreviated as MOD, refers to the closest distance at which a camera lens or optical system is capable of producing a sharp and focused image. In photography, this term...

The smallest linear diameter to which a laser or other beam of radiant energy is capable of being focused, depending on the quality of the focusing optics, aperture and focal length, beam irradiance...

The smallest area of uniform brightness that can be seen by the eye. It is measured in terms of the solid angle subtended by that area from the eye.

A smooth, highly polished surface, for reflecting light, that may be plane or curved if wanting to focus and or magnify the image formed by the mirror. The actual reflecting surface is usually a thin...

A mirror blank refers to the initial piece of material from which a mirror is made. It is typically a flat or slightly curved piece of glass or other substrate that serves as the starting point for...

One 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...

An image-forming system having curved mirrors in place of transparent glass components. Mirror lenses are commonly used for astronomical purposes as well as cheap solutions for very long focal length...

A mirror mount is a mechanical device used to secure and precisely position mirrors in optical systems. Mirrors are essential components in optical setups for reflecting light or redirecting laser...

The 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...

Mitochondria are organelles found in the cytoplasm of eukaryotic cells, which are cells that have a membrane-bound nucleus and other organelles. They are often referred to as the powerhouses of the...

A mixed-signal oscilloscope (MSO) is a type of electronic test instrument that combines the capabilities of both a traditional oscilloscope and a logic analyzer. It is designed to capture and display...

Combining light beams, usually of unlike frequencies, to form a single beam with a frequency that is equal to the frequency sum or difference of the original beams. The resultant 'beat' frequency is...

Modal bandwidth is a crucial parameter in optical fiber communication systems, particularly in multimode fiber (MMF) systems. It quantifies the ability of a fiber optic link to transmit data at high...

Synonym for multimode distortion. Also called mode dispersion.

In compact disc systems, the two principal frame formats for data storage. Mode 1 devotes 2048 bytes to user data, reserving 288 bytes for error detection and correction over and above the CIRC...

In 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...

Synonym (regarded by some as erroneous) for multimode distortion, which see.

For a single-mode fiber, the measurement of the irradiance distribution at the fiber's end face.

Mode hopping in the context of lasers refers to a phenomenon where a laser system abruptly switches from one longitudinal mode to another. In a laser, different longitudinal modes represent distinct...

A device for inducing mode coupling in an optical fiber. Also, a device composed of one or more optical fibers in which strong mode coupling occurs. Also called mode mixer.

A multimode laser characteristic defined as the ratio of power loss for the second mode to that of the lowest mode.

A form of laser output noise that is caused by thermal, mechanical, or acoustical disturbances of the cavity length. Mode sweeping occurs when the length of the laser cavity changes as a result of...

Mode-locking is a technique used in lasers to produce ultrashort pulses of light with durations on the order of picoseconds, femtoseconds, or even attoseconds. This method synchronizes the phases of...

Modified chemical vapor deposition (MCVD) is a technique used in the fabrication of optical fibers. It is a specialized form of chemical vapor deposition (CVD) that is employed to produce...

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...

The modulated transfer function (MTF) is a measure used in optical engineering and imaging science to describe the ability of an optical system to transfer the contrast of an object to an image. It...

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...

MTF analysis/measurement equipment refers to instruments and tools used to measure and analyze the modulation transfer function (MTF) of optical systems. The MTF is a quantitative measure of the...

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...

A nonlinear crystal used to modulate a polarized beam of light by means of the Pockels effect. A Pockels cell is used as a voltage-controlled waveplate by means of applying a known voltage across the...

An optical interference technique widely utilized as a method of nondestructive testing when determining the ray deflection and the modulation transfer function (MTF) of an optical system associated...

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.

Molybdenum diselenide (MoSe2) is a dichalcogenide compound composed of molybdenum (Mo) and selenium (Se). It belongs to the family of transition metal dichalcogenides (TMDs), which have garnered...

In a laser diode, the photocurrent produced by a photodiode that detects the emission from the rear facet of the semiconductor chip. It can be used to provide feedback control of the forward current...

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...

With respect to a crystal, a monoclinic crystal consists of three unequal axes, two of which intersect each other obliquely and yet still form right angles to the third.

A monocyte is a type of white blood cell (leukocyte) that is part of the innate immune system. Monocytes are produced in the bone marrow and circulate in the bloodstream. They are characterized by...

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...