Photonics Dictionary

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.

The distortion of an object's true image as the result of abnormal atmospheric disturbances along the path traveled by the light. The atmospheric disturbances common with mirages are a result of a...

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...

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 homogeneous solid solution with crystal lattice sites occupied, at random, by the molecules or ions of two or more separate compounds

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...

In an optical system, noise created by mode-dependent optical losses and variations in the distribution of radiant power among the modes or relative phases of the modes. Also known as speckle noise.

1. The characteristic of how light propagates through a waveguide that can be designated by a radiation pattern in a plane transverse to the direction of travel. 2. The state of an oscillating system...

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...

In a laser, the fraction of plasma volume used by a particular transverse mode of oscillation, a determinant of the gain available to the mode.

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...

Mode locking is a technique used in optics and laser physics to generate short pulses of light with extremely high peak powers. In mode locking, the phases of different longitudinal modes (specific...

The pulse-to-pulse fluctuations in power distribution among modes of a Fabry-Perot laser, which can result in system-limiting noise.

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...

Modulator/demodulator. An electronic device that modulates and demodulates signals transmitted over communications lines.

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...

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...

The highest frequency at which a laser diode can be driven and still be modulated acceptably that further results in the maximum rate of change (modulation) in output frequency that can be obtained...

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,...

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...

Material hardness scale that is used to characterize the scratch resistance of various materials. This surface hardness evaluation is determined by scratching the surface to be tested with 10...

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...

Contour mapping technique that involves positioning a grating close to an object and observing its shadow on the object through the grating. The resultant moiré fringes correspond to a contour line...

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...