Photonics Dictionary

A lithography method that allows the transfer of fine-pitch gratings from a phase mask into photoresist. The exposure takes place with the light coming under an oblique angle to the mask. The...

The area closest to an aperture or source where the diffraction pattern differs substantially from that observed at an infinite distance, or more specifically, the far field. Also referred to as the...

A scanning probe microscope that analyzes the surface of a specimen by recording the intensity of light as it is focused through a pipette and raster scanned across the specimen at a distance less...

A measurement technique used to determine the spatial distribution profile of an electrical or optical quantity of interest which is provided by multiple scans within the near-field region of a...

In a laser diode, lateral motion of the beam center at the facet when the drive current is changed.

An autocollimator is an optical instrument used for measuring small angular deviations with high precision. It operates on the principle of autocollimation, where a light source is directed onto a...

Azimuthal polarization refers to a specific polarization state of light where the electric field vector of the electromagnetic wave points along the azimuthal direction (around the propagation axis)....

Chalcogenide refers to a class of compounds containing elements from group 16 of the periodic table, which includes sulfur (S), selenium (Se), and tellurium (Te). These elements are known as...

Concave is an adjective used to describe a surface or shape that curves inward or has a hollow or recessed appearance. In the context of geometry or optics, a concave shape is one that curves or...

A lens aberration in which the focal length varies radially outward from the center of the field. It has the effect of making a straight tangential line in the object appear curved in the image,...

A detector array refers to a collection of individual detector elements arranged in a two-dimensional grid or matrix format. Each element within the array is capable of detecting electromagnetic...

Exhibiting the characteristic of materials that are electrical insulators or in which an electric field can be sustained with a minimum dispersion of power. They exhibit nonlinear properties, such as...

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...

The use of a krypton laser system for the measurement of small molecules aligned by an electric field, by analyzing the absorption of linearly polarized light.

The ability of a device to operate without electromagnetically interfering with the operation of nearby equipment and without suffering disturbances from the electromagnetic fields in its designated...

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...

A wide-field multiobject spectroscopy system used in astronomy, in which a bundle of low-loss optical fibers positioned on the target images is rearranged at its other end into a linear array along...

1. A lens situated at or near the plane of an internal image to project the aperture of a previous objective or erector upon the aperture of a following lens. 2. A lens at or near the plane of a...

Fluorescence lifetime refers to the average time it takes for a fluorophore, a molecule that absorbs light at one wavelength and emits it at another, to return to its ground state after being excited...

A free-electron laser (FEL) is a type of laser that generates coherent, high-intensity electromagnetic radiation by using a beam of accelerated electrons as the lasing medium. Unlike traditional...

A frequency comb is a precise and regular series of equally spaced spectral lines, or frequencies, that are generated with great accuracy. The term "frequency comb" is often associated with the Nobel...

1. Also known as near-field diffraction. The field of radiation sent through an aperture in an absorbing screen at large distances as compared with the wavelength and the dimensions of the aperture,...

Functional near-infrared spectroscopy (fNIRS) is a non-invasive neuroimaging technique that measures changes in hemoglobin concentration in the brain. It utilizes near-infrared light to penetrate the...

Fusion ignition refers to the point in a controlled nuclear fusion reaction where the energy released by the fusion reactions becomes self-sustaining, leading to a continuous release of energy...

A GaAlAs laser is a type of semiconductor laser diode that emits light in the near-infrared region of the electromagnetic spectrum. It is composed of layers of gallium, aluminum, and arsenic, hence...

Harmonic generation refers to a nonlinear optical process in which incoming photons interact with a material and produce new photons at integer multiples of the frequency of the incoming photons....

High harmonic generation (HHG) refers to a nonlinear optical process in which intense laser light interacts with a gaseous medium, typically an atom or a molecule, to produce harmonics of the...

That object distance at which a camera must be focused so that the far depth of field just extends to infinity. The near limit of the depth of field is then half the hyperfocal distance. For normal...

A hyperspectral imaging camera is a sophisticated imaging device capable of capturing and processing data across a wide range of wavelengths within the electromagnetic spectrum, typically from...

An InGaAs (indium gallium arsenide) camera is a type of imaging device that utilizes InGaAs sensors to capture images in the near-infrared (NIR) spectrum. InGaAs is a semiconductor material that is...

Indium phosphide (InP) is a compound semiconductor material composed of indium (In) and phosphorus (P). It belongs to the III-V group of semiconductors, where elements from groups III and V of the...

An infrared camera, also known as a thermal imaging camera or IR camera, is a device that captures and visualizes the infrared radiation emitted by objects, revealing temperature variations across...

An infrared lens is an optical component specifically designed and optimized for transmitting, focusing, or manipulating infrared (IR) radiation within the infrared spectrum. These lenses are used in...

An infrared light-emitting diode (IR LED) is a semiconductor device that emits infrared light when an electric current passes through it. Similar to standard LEDs that emit visible light, IR LEDs are...

Infrared (IR) refers to the region of the electromagnetic spectrum with wavelengths longer than those of visible light, but shorter than those of microwaves. The infrared spectrum spans wavelengths...

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 Kerr soliton refers to a specific type of soliton, a self-reinforcing wave packet, that arises in nonlinear optical systems due to the Kerr effect. The Kerr effect is the phenomenon where the...

A device for which the output electric field is linearly proportional to the input electric field, and no new wavelengths or modulation frequencies are generated.

The measured width of the field of view at any distance.

A linear positioning stage, also known as a linear stage or translation stage, is a precision mechanical device used to accurately move and position objects along a linear axis. These stages are...

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...

The linear relationship between input and output optical fields for a given optical system or application that allows the use of a matrix and matrix algebra to define an optical system, or series of...

Metabolic imaging refers to the visualization and quantification of metabolic processes within living organisms, tissues, or cells using various imaging techniques. It provides insights into the...

A microcomb, short for microresonator frequency comb, is a novel photonic device that generates a precise series of evenly spaced optical frequencies, akin to the teeth of a comb, across a broad...