Photonics Dictionary

An amplifying device with a wide tuning range in which an electron gun sends a beam of electrons into a slow-wave structure. The electron beam and the electromagnetic wave move in opposite directions...

The signal formed when two signals, such as light waves, of different frequencies are present simultaneously in a nonlinear device. The frequency of the beat is equal to the difference in frequency...

A signal, generated by an oscillator, that provides the means of synchronization of operations in a data communications network.

A fiber optic communications system that works on the principles of homodyning or heterodyning. The transmitting laser produces an optical wave that is modulated in amplitude, phase or frequency by...

An oscillator that uses a piezoelectric crystal to control its frequency.

A temperature-controlled container used to stabilize the temperature and resonant frequency of a crystal found in a crystal-controlled oscillator.

Continuous conversion of oscillatory energy into heat, relative to time or distance.

An imaging process, similar to specific Doppler mapping radar techniques, that utilizes a laser, an optical imaging system, and a line array of photodetectors and spectrum analyzers. The laser...

A laser oscillator in which two mirrors are separated by an amplifying medium with an inverted population, making a Fabry-Perot cavity. Standard diode lasers are Fabry-Perot lasers.

A type of receiver that uses a local oscillator at a frequency deliberately offset from that of the incoming signal. It is less sensitive than a homodyne receiver, but easier to build because it...

A type of receiver utilizing a local oscillator phase-locked to the incoming signal.

A device that controls the output of a television receiver's horizontal oscillator.

The use of a small ultrastable master oscillator (a diode-pumped Nd:YAG laser) to achieve single-frequency operation of a large pulsed Nd:YAG host laser, providing improved bandwidth and temporal...

In a heterodyne optical receiver, the frequency that is the difference between that of an incoming laser signal and that of the local oscillator laser. Also called beat frequency.

The Kerr effect, named after the physicist John Kerr who first observed it in 1875, is a nonlinear optical phenomenon where the refractive index of a material changes in response to an applied...

A thermionic tube that has a velocity-modulated electron stream and that may be used as a microwave amplifier or oscillator.

Contains elements which produce lasing., e.g. gain medium, oscillator mirrors as well as housing.

Contains the light or beam path within a laser device. The oscillator uses reflective optical components that are oriented to obtain multiple confined reflections.

The material that produces stimulated emission from within a laser oscillator. Laser gain media may vary from extended-length glass fibers to submicron-length semiconductor material.

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.

In coherent optical communications systems, a laser used at the receiving end to produce a steady wave that is combined with the incoming laser signal before detection, generating a composite wave...

A lock-in amplifier is a specialized electronic instrument used to extract and measure small signals embedded in noise or interference. It is particularly useful in fields such as spectroscopy,...

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...

A laser-pumped crystal with nonlinear optical properties inside of an optical resonator in which the output generates coherent light whose output can be tuned continuously over a variety of infrared...

Means of amplifying optical waves whereby an intense coherent pump wave is made to interact with a nonlinear optical crystal to produce amplification at two other optical wavelengths. See parametric...

A device using a parametric amplifier inside a resonant optical cavity to generate a frequency-tunable coherent beam of light from an intense laser beam of fixed frequency. This device is tuned by...

A circuit that uses feedback to synchronize the phase of a voltage-controlled oscillator with the phase of an incoming or reference signal.

The inhibition or elimination of one process by another process. The stimulated emission of a laser oscillator can be quenched by a pulse of radiation of the same frequency traversing the oscillator...

A mode in an optical waveguide whose fields are transversely oscillatory everywhere external to the waveguide. It exists even in the limit of zero wavelength.

A resonator is a device or system that exhibits resonance, which is a phenomenon that occurs when an external force or stimulus is applied at a specific frequency, causing the system to oscillate...