Photonics Dictionary

The acceptance pattern, often used in the context of antennas and optical systems, refers to the spatial distribution of the sensitivity or responsiveness of a device to incoming signals or light....

An active infrared (IR) system is a type of technology that uses infrared radiation actively emitted and detected by sensors for various purposes. Here are the key features and applications of active...

An actuator is a mechanical or electromechanical device that is responsible for moving or controlling a mechanism or system. It converts various forms of energy (such as electrical, hydraulic,...

An ammonia maser is a device that amplifies microwave radiation using ammonia gas molecules in a process analogous to how lasers amplify visible light through stimulated emission of radiation. The...

Analog adaptive resonance theory (AART) is a neural network model within the broader framework of adaptive resonance theory (ART), which was introduced by Stephen Grossberg. ART is a cognitive and...

In fiber optics, the limitation on performance imposed by the amplitude of a received signal rather than distortion.

A ball lens is a small, spherical optical component typically made of glass or other transparent materials. It is characterized by its spherical shape, with both its front and back surfaces forming...

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 light-tight box that receives light from an object or scene and focuses it to form an image on a light-sensitive material or a detector. The camera generally contains a lens of variable aperture...

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...

A signal-averaging technique that improves signal-to-noise ratio by comparing a sampled signal with a reference signal bearing some known relation to the received signal.

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...

Differential mode delay (DMD) is a parameter used to characterize the propagation characteristics of optical fibers, particularly in multimode fiber optic systems. It refers to the difference in...

In a fiber optic transmission system, the conversion of received optical pulses directly to an electrical signal.

The limitation on performance imposed by the distortion of a received signal rather than its amplitude or power.

A signal traveling from transmitter to receiver that has an altered frequency due to the Doppler effect.

A panel of photoconductive and electroluminescent layers used as either a positive or negative image intensifier, depending on amplitude and phase of its two power supply voltages. The...

A device used to transmit and receive images that have been converted to electrical signals over regular telephone lines; it includes a scanner, a transmitter, a receiver and a printer.

A waveguide or coaxial cable that transmits a signal from an antenna to a receiver or from a transmitter to an antenna.

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 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...

FMCW lidar stands for frequency-modulated continuous wave lidar. It is a type of lidar (light detection and ranging) technology used for remote sensing, distance measurement, and 3D mapping. FMCW...

Free-space optics (FSO), also known as optical wireless communication or optical wireless networking, refers to the transmission of data using modulated beams of light through free space (air or a...

Temporal jitter at a signal's receiver when amplified noise causes frequency shifts, as with a soliton traveling through an erbium-doped fiber amplifier.

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...

In optical communications, the translation of optical signals into radio signals, lowering their frequency in detection from greater than 1014 Hz to less than 1010 Hz, so that further signal...

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

Indirect time-of-flight (iTOF) is a method used in 3D imaging and depth sensing to measure the distance to an object based on the time delay between the emission of a light pulse and the detection of...

An InGaAs photodiode refers to a photodetector device that is constructed using a semiconductor material composed of a combination of indium (In), gallium (Ga), and arsenic (As). The term InGaAs...

The process in which the electron beam of a cathode-ray tube varies in intensity in accordance with the magnitude of the signals it receives.

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.

1. In relation to cathode-ray tube displays, errors in the signal's amplitude, phase or both that result in small, rapid aberrations in size or position of the image. 2. Errors of synchronization...

A cathode-ray tube that serves as a picture tube in a television receiver. The signal representing the picture intensity is transmitted to the electron gun grid so that the beam intensity varies with...

LiFi, short for light fidelity, is a wireless communication technology that utilizes visible light or infrared light to transmit data. Developed as an alternative or complementary technology to...

Linear receive optics typically refers to the optical components and systems used in the reception (detection) of linearly polarized light signals in various applications, such as optical...

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 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...

The unwanted and unpredictable fluctuations that distort a received signal and hence tend to obscure the desired message. Noise disturbances, which may be generated in the devices of a communications...

Optical fiber optic switches are devices used in optical fiber communication systems to selectively route optical signals from one input fiber to one or more output fibers. They play a crucial role...

In an optical fiber or waveguide communications system, an optoelectronic device or module that receives an optical signal, converts this optical signal to an electrical signal which is then...

An optical coupling device that uses light to bridge the gap between incompatible wire communications systems. It contains an input amplifier, a light-emitting diode, a photodiode and an output...

A passive optical network (PON) is a telecommunications network architecture that uses optical fibers and passive optical components to provide high-speed broadband services to end-users. In a PON...

Photoconductive antenna (PCA) is a semiconductor element that generates or detects high-frequency electromagnetic signals. Compact PCAs based on gallium arsenide (GaAs) or indium gallium arsenide...