Photonics Dictionary

1. The process by which an atom acquires energy sufficient to raise it to a quantum state higher than its ground state. 2. More specifically with respect to lasers, the process by which the material...

The difference between the energy of an atom in its ground state and that of the same atom in its excited (quantum) state.

The ratio of the intensities of two specified spectral lines of a source having vastly different excitation energies. This ratio indicates the level of excitation energy in the source.

The amount of energy required to raise the energy level of an atom; a necessity if the atom is to radiate energy. High excitation potential is the amount of energy in the upper state of the...

On the CIE chromaticity diagram, the distance from the achromatic point to the sample point, divided by the distance from the achromatic point through the sample point to the spectrum locus or purple...

The amount of x-rays used to penetrate and diffuse a target sample undergoing electron-probe microanalysis.

A method of lasing in which free electrons in a laser-produced plasma collide with neonlike ions to excite electrons to states that decay at different speeds, producing a population inversion.

The use of high temperatures, between 2000 and 3000 °C, to excite emission lines from a sample in spectroscopic analysis.

Diffuse light emitted by the atmosphere due to the excitation of particles of atmospheric gas. These excited particles release light that is visible from Earth as a faint luminescence in the night...

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

gas laser using ionized argon as the active medium and applying electronic excitation in order to produce the laser light

Attosecond-pump attosecond-probe spectroscopy (APAP) is an advanced technique in ultrafast spectroscopy that allows scientists to study the dynamics of electronic processes occurring on extremely...

The energy analysis of electrons released in a secondary step following initial excitation or ionization.

Autofluorescence refers to the natural emission of fluorescence exhibited by certain biological structures or molecules when exposed to light. Unlike fluorescence that results from the application of...

In semiconductor physics, the term bandgap refers to the energy range in a material where no electronic states are allowed. It represents the energy difference between the valence band, which is the...

This type of miniaturized system, referred to as CMOS qPCR, combines microfluidic technology with an ultralow-light CMOS bio-optical sensor with LEDs as the optical excitation source to achieve...

A technique whereby two laser beams, one at an excitation wavelength and the second at a wavelength that produces Stokes Raman scattering, interact coherently in a sample, producing a strong...

Calculation of the probability of an interaction between two types of particles, such as light absorption, excitation or energy transfers. The probability that one incident particle will interact as...

A dichroic mirror, also known as a dichroic beamsplitter or interference filter beamsplitter, is an optical device that selectively reflects or transmits light based on its wavelength. Dichroic...

An electromagnon is a quasiparticle excitation that combines aspects of both magnetism and electric polarization in a crystal lattice. Specifically, it refers to a collective excitation of spins and...

An analytical technique used to determine the nature of extremely small samples by forming the x-ray spectrum of the samples through excitation by a finely focused electron beam.

An emission spectrum is a graphical representation or a characteristic pattern of the wavelengths or frequencies of light emitted by a source, such as an atom, molecule, or celestial object. It shows...

Fluorescence imaging technique in which the excitation light from the objective is directed into the sample producing emission at all angles. Light emitted into the objective is measured allowing the...

The length of optical waveguide needed to attain equilibrium mode distribution for a specified excitation condition.

An optical recording technique that uses light source(s), a beamsplitting cube, light detector(s) and an optical fiber chronically implanted in animal brain to deliver excitation light to neurons...

A microscope in which laser light is delivered through single-mode fibers that replace the pinhole usually used in confocal microscopy. When the Gaussian mode is imaged from the fiber output onto the...

A part of the spectrochemical analysis of a sample that deals with the excitation of that sample by flame analysis.

A pulsed dye laser in which the excitation is provided by means of a flashlamp. Output is tunable from 335 to 850 nm, with peak power up to 7000 kW.

Flow cytometry is a powerful technique used in biology and medicine for the quantitative analysis of the physical and chemical characteristics of cells and particles suspended in a fluid. The method...

Fluorescence is a type of luminescence, which is the emission of light by a substance that has absorbed light or other electromagnetic radiation. Specifically, fluorescence involves the absorption of...

Fluorescence lifetime imaging (FLIM) is an advanced imaging technique that provides information about the lifetime of fluorescence emissions from fluorophores within a sample. Unlike traditional...

Fluorescence microscopy is a specialized optical imaging technique used in biology, chemistry, and materials science to visualize and study specimens that exhibit fluorescence. Fluorescence is the...

Fluorescent proteins are proteins that exhibit the property of fluorescence, which is the ability to absorb light at a specific wavelength and emit light at a longer wavelength. These proteins are...

A fluorescent screen refers to a phosphorescent or fluorescent-coated surface that emits visible light when exposed to other forms of electromagnetic radiation, such as x-rays or ultraviolet light....

A fluorophore is a molecule or a portion of a molecule that has the ability to emit light upon excitation by an external energy source, such as ultraviolet or visible light. The process by which a...

Förster resonance energy transfer (FRET) is a mechanism describing the transfer of energy between two closely spaced fluorescent molecules. This phenomenon is named after the German scientist...

A solid-state laser consisting of active atoms or ions of a transition metal, rare-earth metal or actinide, imbedded in a crystal or glass material, often garnet. Excitation and transfer to different...

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 based on the principle of stimulated emission of photons from excited helium...

Qualitatively, the inverse of the amount of velocity produced by the application of a sinusoidal force to a system; therefore, if velocity is high, impedance at that point is low. Quantitatively,...

Infrared radiation absorbed by crystals as a result of the excitation of lattice vibrations in which ions having opposite charges move relative to one another. These vibrations take place in a narrow...

A phosphor, such as sulfide or selenide, that can be excited to luminescence by incident infrared radiation simultaneous to or following its excitation by visible radiant energy.

A spectroscopic technique in which an excitation band absorbs laser energy resulting in an electronic transition. The isotopic species may then be measured using a time of flight mass spectrometer....

Laser active elements typically refers to the substances or materials within a laser system that play a critical role in the amplification of light through the process of stimulated emission. These...

A source of energy that produces needed excitation for population inversion in laser operation. The excitation source that produces a transition or excitation for a sample, which then can be...

Laser-induced fluorescence (LIF) is a spectroscopic technique that involves using a laser to excite molecules or atoms, leading to their emission of fluorescence light. This technique is widely used...