Photonics Dictionary

Also known as the Wiener spectrum or the noise power spectrum, the optical power spectrum is a fundamental quantity in film-screen image quality evaluation. It is a means of describing image content...

Acoustical holography is a technique used to visualize and analyze sound fields in three-dimensional space. It involves capturing the complex spatial distribution of acoustic waves, much like how...

An active medium is a material or substance used in various optical devices and systems, where it plays a critical role in amplifying light or producing laser beams through the process of stimulated...

Angular deviation from the optimum alignment of source to optical waveguide, waveguide to waveguide, or waveguide to detector, resulting in a loss of optical power.

The rate of diminution of average optical power and the sum of the scattering and absorption coefficients.

An attenuator is an electronic or optical device used to reduce the power or intensity of a signal without significantly affecting its waveform or other characteristics. Attenuators are commonly used...

A low-power telescope placed at the eyepiece of an optical system to increase overall magnification. Most often used to evaluate image quality.

Beam profiling is a technique used to characterize and analyze the spatial intensity distribution of a laser beam. It involves measuring and visualizing how the optical power or intensity is...

The loss of optical power in an optical fiber because radiation escapes through its bends. The radiation loss caused by fiber bending is proportional to the bend radius.

Blaze height typically refers to a parameter in the context of diffraction gratings, which are optical devices consisting of a series of closely spaced parallel grooves or slits. The blaze height is...

Brillouin microscopy is a non-invasive imaging technique that utilizes Brillouin scattering to measure the mechanical properties of materials at the microscale. This advanced optical technique...

Brillouin scattering is a phenomenon in physics where an incident electromagnetic wave (usually light) interacts with acoustic phonons (quantized lattice vibrations) in a material, resulting in the...

A CCD image sensor, or charge-coupled device image sensor, is a type of electronic device used to convert optical images into electronic signals. It is a key component in digital cameras, camcorders,...

In optics and photonics, ceramics refer to advanced ceramic materials that possess unique optical properties, making them suitable for various applications involving the manipulation and control of...

Chirped mirrors are optical devices designed to manipulate the spectral properties of ultrashort laser pulses. They consist of multiple layers of dielectric coatings deposited on a substrate, where...

Coherent anti-Stokes Raman spectroscopy (CARS) is a powerful technique used in spectroscopy to probe molecular vibrations in a sample. It is based on the Raman effect, which involves the inelastic...

The use of phase conjugation or other methods to increase the power density of a laser beam under adverse atmospheric conditions.

Reciprocal of the dispersive power of an optical material. See Abbe constant.

A corner cube, also known as a corner reflector or retroreflector prism, is a type of optical device used to reflect light or electromagnetic waves back towards their source with minimal deviation in...

1. In color development, the chemical that combines with certain by-products of the development procedure to form a dye. 2. Device for distributing optical power among two or more ports. 3. Device...

Dense wavelength division multiplexing (DWDM) is an optical communication technique used to increase the data-carrying capacity of optical fiber networks by simultaneously transmitting multiple...

A flanged or plain ring with a restricted aperture, located in an optical system at any of several points, that cuts off marginal light rays not essential to image formation. Diaphragms are used as...

Diffraction efficiency is a measure of how effectively a diffractive optical element (DOE) or diffraction grating directs light into specific diffraction orders or achieves a desired optical effect....

A diode laser is a type of laser that uses a semiconductor diode as the active medium to generate coherent light. Semiconductor diodes are electronic devices that conduct electricity primarily in one...

A unit of optical measurement that expresses the refractive power of a lens or prism. In a lens or lens system, it is the reciprocal of the focal length in meters. For example, if a lens has a focal...

Double-clad fiber (DCF) is a specialized optical fiber that features two concentric cladding layers surrounding a core. The design of double-clad fibers allows them to be used in various...

An electro-optic deflector is a device that can change the direction of light beams using an electric field. It operates based on the electro-optic effect, which involves the modulation of the...

Emission spectroscopy is a technique used to study the emission of electromagnetic radiation (light) by atoms, molecules, or ions when they undergo transitions from excited states to lower energy...

A laser that distributes its output power among two, three or four optical fibers simultaneously.

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

A femtosecond laser is a type of laser that emits ultrashort pulses of light with durations on the order of femtoseconds, where one femtosecond is equal to 10-15 seconds. These lasers are capable of...

The lowest frequency at which the magnitude of the fiber transfer function decreases to a specified fraction of the zero frequency value. Often, the specified value is one-half the optical power at...

A phenomenon in which high optical power, encountering an imperfection in an optical fiber, destroys the fiber's core and causes damage to back-propagate down the fiber. It is caused by classic...

A fiber laser is a type of laser in which the active gain medium is an optical fiber doped with rare-earth ions such as erbium, ytterbium, or neodymium. Fiber lasers generate coherent light through...

A fiber optic attenuator is a passive optical component designed to attenuate or decrease the intensity of an optical signal traveling through a fiber optic link. It achieves this by introducing a...

A fiber optic spectrometer is a device used for measuring the spectral content of light. It utilizes optical fibers to transmit light from a source to a spectrometer unit, where the light is...

A fiber optic transceiver, often simply referred to as an "optical transceiver," is a device used in fiber optic communications to transmit and receive data over optical fibers. It integrates both a...

A fiber-coupled LED (light-emitting diode) refers to an LED device that is optically coupled to an optical fiber for the purpose of efficient light transmission. In this configuration, the LED serves...