Photonics Dictionary

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.

An operational mode for radiometers that analogs the method of operation of an angstrom pyrheliometer. In this mode, the rearward-facing cavity is electrically heated, while the forward cavity is...

A method of data multiplexing that can provide large, instantaneous bandwidths for busy traffic while permitting slow traffic to use that bandwidth between bursts. Very short, fixed-length packets or...

A high-frequency pulse-rate laser with an output limited by the heat capacity of the laser medium. Instead of having continuous cooling, the laser operates until the medium reaches a maximum...

A mode that is confined by virtue of a lower-index medium surrounding the cladding. Cladding modes, in the terminology of mode descriptors, are equivalent to cladding rays in the terminology of...

A mechanism or device, especially a coating with a refractive index equal to or slightly greater than that of an optical fiber's cladding, that removes modes propagating through the cladding by...

A ring dye laser that uses prisms and a saturable absorber within the laser cavity to shape and shorten the pulses generated. Counterpropagating modes oscillating simultaneously in the ring...

An electrical problem that occurs when voltage is not the same with respect to ground at every node of a system, causing current to circulate between nodes.

A type of photoelectric proximity mode sensing incorporating a lens system to focus the light from the emitter in a small, concentrated spot at a specific point in front of the sensor. Also referred...

An operate mode in which the sensor is programmed to perform a task such as generating output when the light level falls below a certain threshold.

The variation in attenuation among the propagating modes of an optical fiber.

A variation in propagation delay caused by differences in group velocity among modes of an optical fiber. Also called multimode group delay, this effect is commonly due to imperfections or any...

Use of a photoelectric receiver to sense an object's presence by detecting a small amount of the emitter's light that is diffusely reflected by the object.

A type of glass optical fiber that provides low pulse dispersion over a broad portion of the light spectrum and as a result can operate at 1300-nm and 1550-nm wavelengths simultaneously.

The condition in a multimode optical waveguide in which the relative power distribution among the propagating modes is independent of length.

The lowest order mode of a waveguide. In fibers, the mode designated LP01 or HE11.

In an optical waveguide, a mode whose field decays monotonically in the transverse direction everywhere external to the core and which does not lose power to radiation. Also called bound mode.

Designation for the fundamental mode of an optical fiber.

A mode possessing components of both electrical and magnetic field vectors in the direction of propagation.

In a diode laser, a mode in the plane of the active layer that is perpendicular to the direction of the emitted beam.

In an optical waveguide, a mode whose field decays monotonically for a finite distance in the transverse direction but which becomes oscillatory everywhere beyond that finite distance.

A waveform that can oscillate along the length of the laser cavity.

The Lorentz oscillator model is a theoretical model used in physics to describe the response of a charged particle (such as an electron) to an oscillating electric field. It is particularly employed...

Calculation of gas and aerosol transmission and emission characteristics for several model atmospheres, including two model aerosol distributions.

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

Used in computer design for optical systems with common parts and different applications.

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...