Spectroscopy

Singlet oxygen is a high energy form of oxygen.

Nuclear magnetic resonance spectroscopy, most commonly known as NMR spectroscopy, is a research technique that exploits the magnetic properties of certain atomic nuclei.

Stokes shift is the difference (in wavelength or frequency units) between positions of the band maxima of the absorption and emission spectra (fluorescence and Raman being two examples) of the same electronic transition.

In atomic physics, hyperfine structure is the different effects leading to small shifts and splittings in the energy levels of atoms, molecules and ions.

Electron paramagnetic resonance (EPR) or electron spin resonance (ESR) spectroscopy is a method for studying materials with unpaired electrons.

In atomic physics, Hund's rules refers to a set of rules that German physicist Friedrich Hund formulated around 1927, which are used to determine the term symbol that corresponds to the ground state of a multi-electron atom.

Phosphorescence is a specific type of photoluminescence related to fluorescence.

In physics, a spectrometer is an apparatus to measure a spectrum.

Raman scattering or the Raman effect /ˈrɑːmən/ is the inelastic scattering of a photon upon interaction with matter.

A spectrum analyzer measures the magnitude of an input signal versus frequency within the full frequency range of the instrument.

Chemiluminescence (sometimes "chemoluminescence") is the emission of light (luminescence), as the result of a chemical reaction.

The power spectrum of a time series describes the distribution of power into frequency components composing that signal.

The term quantum efficiency (QE) may apply to incident photon to converted electron (IPCE) ratio, of a photosensitive device or it may refer to the TMR effect of a Magnetic Tunnel Junction.

Ultraviolet–visible spectroscopy or ultraviolet-visible spectrophotometry (UV-Vis or UV/Vis) refers to absorption spectroscopy or reflectance spectroscopy in the ultraviolet-visible spectral region.

In physical and analytical chemistry, colorimetry or colourimetry is a technique "used to determine the concentration of colored compounds in solution.

X-ray spectroscopy is a gathering name for several spectroscopic techniques for characterization of materials by using x-ray excitation.

Spectral hole burning is the frequency selective bleaching of the absorption spectrum of a material, which leads to an increased transmission (a "spectral hole") at the selected frequency.

The absorption of electromagnetic radiation by water depends on the state of the water.

A frequency comb is a spectrum consisting of a series of discrete, equally spaced elements.

Rotational–vibrational spectroscopy is a branch of molecular spectroscopy concerned with infrared and Raman spectra of molecules in the gas phase.

Spectral line shape describes the form of a feature, observed in spectroscopy, corresponding to an energy change in an atom, molecule or ion.

Opacity is the measure of impenetrability to electromagnetic or other kinds of radiation, especially visible light.

Fluorescence correlation spectroscopy (FCS) is a correlation analysis of fluctuation of the fluorescence intensity.

Vibronic spectra involve simultaneous changes in the vibrational and electronic energy states of a molecule.

A single-molecule experiment is an experiment that investigates the properties of individual molecules.

Cyclopropyl cyanide is the smallest carbon ring molecule with a cyanide group attached to it.

In rotational-vibrational and electronic spectroscopy of diatomic molecules, Hund's coupling cases are idealized cases where specific terms appearing in the molecular Hamiltonian and involving couplings between angular momenta are assumed to dominate over all other terms.