Photonics Dictionary: M

Synonym for multimode distortion. Also called mode dispersion.

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 an optical waveguide, the exchange of power/energy among modes.

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.

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.

A device used in measuring the attenuation of multimode optical fibers. A short reference length of fiber when combined with the mode filter has approximately the same angular output distribution of...

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 condition causing variation in output power that is eliminated by mode locking.

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

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...

The number of bound modes that an optical waveguide is capable of supporting.

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...

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...

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...

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...

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...

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 method of predicting the nonlinear optical effects exhibited by different molecules without synthesizing the molecules themselves.

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.