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 lidar operates on the principle of sending out laser...

With a repetitive object such as a series of equispaced lines, the reciprocal of the line spacing in object or image,...

The determination of the relative phase shift of an image as a function of frequency. A phase change of 180° with...

A device using a parametric amplifier inside a resonant optical cavity to generate a frequency-tunable coherent beam of...

Surface-enhanced Raman spectroscopy (SERS) is an analytical technique that combines the principles of Raman spectroscopy...

Adaptive optics (AO) is a technology used to improve the performance of optical systems by reducing the effects of...

For a pulsed laser, the product of the energy per pulse (joule) and the pulse frequency (hertz); expressed in watts.

When light is transmitted through matter, part of the light is scattered in random directions. A small part of the scattered...

Rolling shutter artifacts are distortions or visual anomalies that can occur in images or videos captured by cameras with...

The angular spectrum approach is a mathematical and computational technique used in the field of optics to analyze and...

The frequency band from 300 to 3000 MHz. The corresponding wavelengths are from 10 to 100 cm.

The constant that, multiplied by the frequency of the radiation-producing emission of photoelectrons, determines the amount...

Phase distortion refers to a change in the phase relationships between different frequency components of a signal. In the...

A helium-neon (HeNe) laser is a type of gas laser that emits visible red light at a wavelength of 632.8 nm. It operates...

A phenomenon that causes the details in an image to appear at a spatial frequency higher than that at which the contrast...

Oscillator device composed of a semiconducting diode in a coaxial resonating cavity. When the biasing current is applied to...

Distortion of the high frequencies of a signal. In television, the term generally applies to frequencies above the 15.7 kHz...

Supercontinuum refers to a broad spectrum of light that spans a wide range of wavelengths, typically from the visible to the...

Self-phase modulation (SPM) is a nonlinear optical phenomenon that occurs when an intense laser beam passes through a...

A distributed feedback laser (DFB laser) is a type of semiconductor laser diode designed to emit coherent, narrow-bandwidth...

Extreme ultraviolet (EUV) refers to a specific range of electromagnetic radiation in the ultraviolet part of the spectrum....

A waveguide is a physical structure or device that is designed to confine and guide electromagnetic waves, such as radio...

The Kerr effect, named after the physicist John Kerr who first observed it in 1875, is a nonlinear optical phenomenon where...

Brillouin scattering is a phenomenon in physics where an incident electromagnetic wave (usually light) interacts with...

A phase-modulated sensor is a type of sensor that uses modulation of the phase of a signal to measure changes in a physical...

With respect to a traveling plane wave at a known frequency, the space rate of decrease of phase of a field component in the...

The fundamental wavelength standard of time or frequency. An atomic standard, it is properly expressed as 9,192,631,770...

A quantum cascade laser (QCL) is a type of semiconductor laser that operates based on the principles of quantum mechanics....

A type of receiver that uses a local oscillator at a frequency deliberately offset from that of the incoming signal. It is...

The function that characterizes the quality of an optical system by denoting the modulation and spatial phase shift of the...

The frequency space between consecutive transmission peaks in the transmission spectrum of a Fabry-Perot interferometer or...

MTF analysis/measurement equipment refers to instruments and tools used to measure and analyze the modulation transfer...

For a particular mode, the reciprocal of the rate of change of the phase constant with respect to angular frequency.

The term half bandwidth (HBW) generally refers to the width of a spectral band or frequency range at half of its maximum...

An optical clock is a highly precise and advanced timekeeping device that relies on the oscillations of electromagnetic...

A phenomenon, exploited for medical imaging, in which the nuclei of material placed in a strong magnetic field will absorb...

A femtosecond laser is a type of laser that emits ultrashort pulses of light with durations on the order of femtoseconds,...

Linear optics refers to the study and manipulation of light in a linear and deterministic manner, where the response of...

Electromagnetic energy is transmitted in the form of a sinusoidal wave. The wavelength is the physical distance covered by...

Calculates the exponential growth of the least stable spatial frequency in a laser beam, and is the numerical equivalent of...

The interaction between two oscillations of unlike frequencies that forms other oscillations, specifically those with a...

A unit of frequency equivalent to 1012 cps. Named for Augustin Jean Fresnel, a French physicist known for his work in light...

A laser warning and countermeasure system containing a sensor that indicates the direction of a laser beam, and analytical...

The complex function, H(f), equal to the ratio of the output to input of the device as a function of frequency. The...

A device designed to measure the amplitude and frequency of the elements in a complex waveform.

The phenomenon observed by A.H. Compton in 1923 -- that some scattered radiation possesses a longer wavelength and...

In general, changes in one oscillation signal caused by another, such as amplitude or frequency modulation in radio which...

The use of a variable transmission filter at the aperture stop of a lens to modify its diffraction pattern. Reduced...

Dispersion that occurs when the medium's index of refraction decreases as the frequency of the propagating light increases....

A high-frequency approach to the propagation of light in graded-index fibers in which the modal field is represented in...

An acousto-optic modulator (AOM) is a device that utilizes the interaction between sound waves and light waves to modulate...

Also referred to as the V number in fiber optics; the normalized frequency is a dimensionless quantity, denoted by the...

X-rays emitted by a substance that formerly has been exposed to x-rays. The properties of the substance determine the...

Present in photocurrent burst, it is the low frequency pulse that corresponds to the light scattered from the beams in the...

The frequency domain is a concept used in signal processing and analysis to represent signals and data in terms of their...

A technique for detecting and measuring atmospheric pollution, in which an oscillating mirror directs half the incoming...

Also known as the Wiener spectrum or the noise power spectrum, the optical power spectrum is a fundamental quantity in...

The random noise having a spectral density that is substantially independent of the frequency over a specified frequency...

The individual coherent series of lightwaves that defines a quantum of radiant energy. Light quantum is equal to hv, h being...

In optical communications, the translation of optical signals into radio signals, lowering their frequency in detection from...

An acronym for microwave amplification by stimulated emission of radiation. Predecessor to the laser, the maser or...

The law stating that the critical fusion frequency is approximately proportional to the logarithm of the luminance and the...

Phase matching is a crucial concept in the field of optics, particularly in nonlinear optics and the generation of coherent...

A glow discharge tube placed on an insulating rod to detect the presence of high-frequency radiation in the vicinity of a...

A high-frequency pulse-rate laser with an output limited by the heat capacity of the laser medium. Instead of having...

The spectroscopic analysis of optical line shapes and frequency shifts, using the technique of light beating; i.e., the...

Any noise with a power spectral density that is the inverse of the signal's frequency and is therefore most significant for...

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

A lamp that has mercury in a tube or bulb that has first been evacuated. The electricity travels through the vapor between...

A fiber optic sensor is a device that uses optical fibers to detect and measure physical, chemical, biological, or...

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

A gas laser in which the electrodes are mounted perpendicular to the optical resonator.

The detection and analysis of naturally formed extraterrestrial electromagnetic radiation within the radio frequency range...

Spectroscopy is a technique used in the study of interactions between matter and electromagnetic radiation. It involves...

An acronym for communications intelligence, referring to the collection of communications signals in the VHF and UHF...

A metal-semiconductor-metal (MSM) photodiode is a type of photodetector that consists of metal electrodes on a semiconductor...

Laser drift typically refers to a phenomenon where the frequency or wavelength of a laser source gradually changes over...

A detector sensitive only to signals close to or at a particular frequency that is the same as the frequency of a control...

Gallium nitride (GaN) is a compound made up of gallium (Ga) and nitrogen (N). It is a wide-bandgap semiconductor material...

A unit of frequency equivalent to one cycle per second.

The tendency of charge carriers to spiral about an axis in a direction identical to that of an applied magnetic field that...

A laser in which the transition involved in stimulated emission of radiation takes place between two levels of an ionized...

The use of two lasers as a master-slave pair in order to control frequency and prevent chirp. When light from the master is...

A holographic grating is a type of diffraction grating that is produced using holographic recording techniques. It consists...

Heterochromatic photometry that depends on the elimination of chromatic flicker at a lower frequency than luminance flicker.

The internet of things (IoT) refers to a network of interconnected physical devices, vehicles, appliances, and other objects...

Resonance can be defined in various contexts, including physics, chemistry, and music. Here are definitions for resonance in...

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

Frame rate refers to the frequency at which consecutive images, or frames, are displayed in a video sequence. It is...

A very uncommon lamp in which a tungsten electrode is heated to incandescence by a radio-frequency electrical current.

An instrument designed for laser technology that is used to extract single pulses from the laser and transmit a portion of...

Literally the opposite of resonance, antiresonance occurs when any variation in excitation frequency results in an increased...

A small xenon-filled tube with metal electrodes fused into the ends. The gas flashes brilliantly when a condenser is...

Tip-enhanced Raman scattering (TERS) is a powerful technique that combines Raman spectroscopy with the enhanced spatial...

A photodiode having a conducting grid that covers the surface of the photodiode junction and intercepts and wastes some of...

The process by which laser emission is used in measuring fluid velocity and, more specifically, the detection of air and...

The universal constant h that has a value of 6.6260693 x 10-34 Js. A quantum of energy is equal to the product of the...

An instrument designed to collect naturally formed extraterrestrial electromagnetic radiation within the radio frequency...

End-fire coupling refers to a method of coupling energy into or out of a waveguide, transmission line, or antenna, where the...

Also duty factor, duty ratio. The product of the pulse duration and the pulse repetition frequency of a wave composed of...

A blackbody source, often simply referred to as a blackbody, is a theoretical or practical physical object that absorbs all...

An electromagnetic wave lying within the region of the frequency spectrum that is between about 1000 MHz (1 GHz) and 100,000...

A transducer is a device or component that converts one form of energy into another. It is commonly used in various fields,...

Dispersion characterized by an increasing index of refraction in the medium as the frequency of the propagating light...

A microbubble resonator is a device used in photonics and optical physics for the precise manipulation of light waves. It...

In an avalanche photodiode, the gain multiplied by the signal frequency in MHz.

For an electromagnetic field mode varying sinusoidally with time at a given frequency, the logarithmic rate of change, with...

The number of fields scanned per second in a television system. The US standard is 60. Also called field frequency.

A means of achieving higher peak powers and more efficient harmonic generation by narrowing the pulse width and thus...

The transfer of energy from an incident electromagnetic energy field with wavelength or frequency to an atomic or molecular...

Second-order nonlinear optical properties refer to a class of phenomena exhibited by certain materials in response to...

Combining light beams, usually of unlike frequencies, to form a single beam with a frequency that is equal to the frequency...

An electro-optic modulator (EOM) is a device used to modulate the amplitude, phase, or polarization of light waves using an...

Attenuation refers to the gradual loss or reduction of intensity, force, or magnitude of a particular property as it...

Nonlinear optics is a branch of optics that studies the optical phenomena that occur when intense light interacts with a...

Radiation emitted from vibrating charged particles. A combination of oscillating electrical and magnetic fields that...

A filter possessing one transmission band that extends from a cutoff frequency other than zero to frequency at infinity.

LiFi, short for light fidelity, is a wireless communication technology that utilizes visible light or infrared light to...

Harmonic generation refers to a nonlinear optical process in which incoming photons interact with a material and produce new...

In a heterodyne optical receiver, the frequency that is the difference between that of an incoming laser signal and that of...

In reference to infrared, emissions that are like radio waves but that have a higher frequency.

That radiation emitted by an atom or molecule that has the same frequency as that of an incident particle; e.g., a photon....

The signal formed when two signals, such as light waves, of different frequencies are present simultaneously in a nonlinear...

Also known as light beating. The mixing of two narrowband optical components to produce an AC component in the photocurrent...

For a particular mode in a waveguide, the ratio of the angular frequency to constant phase.

The fusion frequency of flicker that is needed just to produce complete fusion and to assure the visual sensation of...

A fiber optic communications system that works on the principles of homodyning or heterodyning. The transmitting laser...

The highest frequency at which a laser diode can be driven and still be modulated acceptably that further results in the...

A device that converts data transmitted in the parallel mode to a sequence of bits at a single frequency for output in the...

The lowest frequency at which the magnitude of the fiber transfer function decreases to a specified fraction of the zero...

A graphic representation of a distribution function such as frequency by means of rectangles whose widths represent the...

The use of a small ultrastable master oscillator (a diode-pumped Nd:YAG laser) to achieve single-frequency operation of a...

Radiation similar in origin to spontaneous emission but determined by the presence of other radiation having the same...

A hologram formed without lenses and with the object and reference points sharing the same plane. In the initial recording,...

High harmonic generation (HHG) refers to a nonlinear optical process in which intense laser light interacts with a gaseous...

A pulsed laser that emits a recurring pulsed output. Frequency of the pulses emitted is known as pulsed recurrence frequency...

Indium phosphide (InP) is a compound semiconductor material composed of indium (In) and phosphorus (P). It belongs to the...

Rate at which optical radiation or a signal is varied through the use of a mechanical or electronic chopper. Also called...

A device used to accelerate the electrons in a free-electron laser. There are several types, including the induction linear...

The law given by the formula: that is, the frequency of radiation emitted or absorbed by a system when E2 and E1...

A resonator is a device or system that exhibits resonance, which is a phenomenon that occurs when an external force or...

Noise over a specified frequency range, in which the spectral density is proportional to the frequency instead of being...

Structured illumination microscopy (SIM) is an advanced optical imaging technique used in microscopy to enhance the...

1. The angle between two vectors that represent two simple periodic quantities that vary sinusoidally and that have the same...

1. In relation to cathode-ray tube displays, errors in the signal's amplitude, phase or both that result in small, rapid...

Used in halftone screens to change the fundamental sampled spatial frequency of the halftoned picture, as well as varying...

A quantum of electromagnetic energy of a single mode; i.e., a single wavelength, direction and polarization. As a unit of...

Also called scanning laser acoustic microscope. A device that uses high-frequency ultrasound waves to penetrate surfaces. A...

A swept-source laser, also known as a wavelength-swept laser, is a type of laser that rapidly and continuously changes its...

In image acquisition (and sampling theory), the postulate that the pickup sampling frequency must be a minimum of twice as...

Also called sine wave response and contrast transfer function. The modulation transfer function is the ratio of the...

The effect produced on a wave frequency because of the relative motion of a source or an observer. The radiation emitted...

Mode hopping in the context of lasers refers to a phenomenon where a laser system abruptly switches from one longitudinal...

An atomic clock is a highly precise timekeeping device that uses the vibrations or oscillations of atoms as a reference for...

A device, such as a thermionic or crystal diode, that is introduced into the vision channel of a television receiver to...

A lack of resolution in a television image as a result of smear ghosts or an insufficiently high video-frequency response....

The time domain is a concept used in signal processing and analysis to describe signals in terms of their behavior over...

The frequency of a wave divided by its velocity of propagation; the reciprocal of the wavelength.

The magnitude, expressed in cycles per second, of the alteration of the wave frequency observed as a result of the Doppler...

A modulator is a device or component that modifies a carrier signal in order to encode information for transmission over a...

A frequency comb is a precise and regular series of equally spaced spectral lines, or frequencies, that are generated with...

A device consisting of an airtight quartz tube that holds the material to be analyzed. When a high-frequency electrostatic...

Mode-locking is a technique used in lasers to produce ultrashort pulses of light with durations on the order of picoseconds,...

Photonic crystals are artificial structures or materials designed to manipulate and control the flow of light in a manner...

A lock-in amplifier is a specialized electronic instrument used to extract and measure small signals embedded in noise or...

The frequency band from 30 to 300 MHz. The corresponding wavelengths are from 1 to 10 m. (VHF).

Nonlinear optical materials are substances that exhibit optical properties that are not linearly proportional to the...

A device that is fabricated in a single piece; A device (i.e. circuit) that is operated at a single frequency or a single...

In Stimulated Brillouin Scattering (SBS), an incident photon (usually laser light) interacts with acoustic phonons in a...

Raman spectroscopy is a technique used in analytical chemistry and physics to study vibrational, rotational, and other...

Technology that relies on a highly efficient photodetector that can detect incoming light signals at one frequency and...

The frequency band from 3 to 30 kHz. The corresponding wavelengths are from 10 to 100 km. (VLF).

A broadband filter is an electronic or electromagnetic device designed to pass a range of frequencies or signals within a...

That element of a spectrum line in scattered radiation having a frequency equal to that of the corresponding incident...

The number of times per second that the frame of a television system is completely scanned. In the United States, 30 per...

Mod Method of obtaining precise temporal mode characteristics.

A nonlinear optical process in which the frequency of an optical beam is doubled coherently.

The wavelength or frequency corresponding to an absorption resonance with a given molecular or atomic species. The line...

In semiconductor physics and materials science, the term "III-V materials" refers to compounds composed of elements from...

Photoconductive antenna (PCA) is a semiconductor element that generates or detects high-frequency electromagnetic signals....

That branch of spectroscopy that applies to the study of interactions between energy and atomic nuclei. The simultaneous...

A unit of frequency that equals 1000 cps. Abbreviated kHz.

A laser that emits energy in a series of short bursts or pulses and that remains inactive between each burst or pulse. The...

Digital signal processing (DSP) refers to the manipulation and analysis of signals, which are representations of physical...

An ultrafast laser is a type of laser that emits extremely short pulses of light with durations typically on the order of...

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

X-rays of one frequency or a narrow band of frequencies.

A system that allows the transmission of more than one signal over a common path, by assigning each signal a different...

GaN (Gallium Nitride) distributed feedback (DFB) lasers refer to a specific type of semiconductor laser based on Gallium...

The law stating that the brightness of an object that is examined through a slotted disc, rotating over a critical...

A device used to accelerate the electrons in a free-electron laser by channeling microwave energy into waveguide cavity...

At a given modulation frequency, wavelength, and for a given effective noise bandwidth, the radiant power that produces a...

With reference to electromagnetic radiation, the number of crests of waves that pass a fixed point in a given unit of time,...

In a thermal imaging system, the smallest change in blackbody equivalent temperature that can be detected clearly by the...

The inhibition or elimination of one process by another process. The stimulated emission of a laser oscillator can be...

Continuous wave (CW) refers to a type of signal or transmission where the signal is constant and does not vary with time. In...

Quantum sensing refers to a class of sensing technologies that leverage principles from quantum mechanics to enhance the...

A mode of transmission whereby the sending and receiving stations operate continuously at a fixed relationship of phase and...

Terahertz (THz) refers to a unit of frequency in the electromagnetic spectrum, denoting waves with frequencies between 0.1...

A Kerr soliton refers to a specific type of soliton, a self-reinforcing wave packet, that arises in nonlinear optical...

A laser diode module is a compact device that incorporates a laser diode, optics, and often other components into a single...

A device designed to detect frequency-modulated signals by forming a unidirectional pulse from each sine wave. The direct...

An electronic flash tube in which the flash recurs at a frequency extending to many thousands per second. A stroboscopic...

A slight displacement in the position of a spectral line because of an alteration in frequency, as a result, in turn, of a...

In digital data transmission, the separation of the two binary states into output at two frequencies.

A type of fluorescence spectroscopy in which an excimer laser, a dye laser and a frequency-doubling device are used to...

Second-harmonic generation (SHG) is a nonlinear optical process that occurs when two photons with the same frequency combine...

Distortion caused by variations in the rate of change of phase shift with frequency over the signal's necessary bandwidth.

Ultrasonic refers to sound waves with frequencies higher than the upper audible limit of human hearing, typically above...

The combination of two waves having the same frequency and amplitude and traveling in opposite directions. Standing waves...

1. The decrease of the absorption (or gain) coefficient of a medium near some transition frequency when the power of the...

Nd:YAG laser refers to a solid-state laser that utilizes neodymium-doped yttrium aluminum garnet (Nd:Y3Al5O12) as the gain...

A mathematical transformation used in image and video compression that changes two-dimensional representation of data into...

A microcomb, short for microresonator frequency comb, is a novel photonic device that generates a precise series of evenly...

The optical Fourier transform is a mathematical operation applied to optical signals that involves transforming a spatial...

Imaging radar that increases the sweep of its along-track (or azimuth) capacity by measuring not only the time delay of the...

The Lorentz oscillator model is a theoretical model used in physics to describe the response of a charged particle (such as...

Light from a pulsed laser focused into nonsaturable absorbing fluid that generates a strongly backscattered light beam with...

Relative to a light source, the frequency at which the source appears to fluctuate in light intensity half the time and...

An absorption peak refers to a sharp increase or spike in the absorption of electromagnetic radiation at a particular...

A technique used in holography that involves the mixing of lasers of different wavelengths to produce a beam of shorter...

The frequency range for radio and television transmission.

A maser that relies on the fact that electrons in orbital motion in high-magnetic fields will emit energy at the cyclotron...

The decrease in the energy of a photoelectric emission as a result of the simultaneous incidence of radiation having lower...

The laser output refers to the generated and emitted light produced by a laser system. This output is characterized by...

An etalon is an optical device that consists of two parallel reflecting surfaces separated by a precise and known distance....

A spectroscopic technique used to display the intensity of an optical pulse as functions of time and frequency...

In optics, an octave typically refers to a range of frequencies or wavelengths that spans a factor of 2. In other words,...

A chemical detection technique used to measure molecules that have a magnetic dipole moment. The analysis is directed to...

An analog signal capable of being modulated as to frequency, amplitude or phase to carry information.

A fundamental law of quantum theory which states that the discrete quanta of energy transfers associated with...

Number of pulses emitted per unit of time by a pulsed laser.

A synchrotron is a type of particle accelerator that uses magnetic fields to steer charged particles, typically electrons or...

The change in refractive index that occurs as acoustic vibrations are transmitted through an optical material.The index...

In image processing, the result of a sampling frequency that is too slow to preserve the spatial frequencies of the image....

A scanning device used to cyclically tune through a given frequency range to determine the amplitude-frequency distribution...

That state determining that two waves of like frequency will travel through their maximum and minimum values of the same...

Optical materials refer to substances or compounds specifically chosen for their optical properties and used in the...

A device that changes the frequency of light by inducing the Raman effect on a beam passing through it.