Laser Spectroscopy

Also found in: Dictionary, Thesaurus, Medical.

Laser spectroscopy

Spectroscopy with laser light or, more generally, studies of the interaction between laser radiation and matter. Lasers have led to a rejuvenescence of classical spectroscopy, because laser light can far surpass the light from other sources in brightness, spectral purity, and directionality, and if required, laser light can be produced in extremely intense and short pulses. The use of lasers can greatly increase the resolution and sensitivity of conventional spectroscopic techniques, such as absorption spectroscopy, fluorescence spectroscopy, or Raman spectroscopy. Moreover, interesting new phenomena have become observable in the resonant interaction of intense coherent laser light with matter. Laser spectroscopy has become a wide and diverse field, with applications in numerous areas of physics, chemistry, and biology. See Laser, Spectroscopy

Spectroscopy, Laser


a branch of optical spectroscopy whose methods are based on the use of laser radiation. By employing monochromatic laser radiation, quantum transitions can be induced between specific atomic and molecular energy levels. By contrast, spectroscopy based on nonlaser light sources studies spectra resulting from transitions between an enormous number of quantum states of atoms and molecules.

The first serious laser experiments in spectroscopy were carried out after sufficiently powerful lasers were developed with an output radiation of a fixed frequency in the visible region. Such lasers were used to produce Raman spectra. The advent of the frequency-tunable laser opened up fundamentally new possibilities for laser spectroscopy. Through laser spectroscopy it became possible to solve or to attempt to solve important problems that could not be handled by spectroscopy based on conventional light sources.

The high monochromaticity of the radiation from tunable lasers permits the measurement of the true shape of the spectral lines of a substance—that is, the shape undistorted by the spread function of the spectroscopic device. This development is particularly important for the spectroscopy of gases in the infrared region, where the resolution of the best industrial devices of the usual type is 0.1 cm, which is 100 times greater than the width of narrow spectral lines.

The methods of nonlinear laser spectroscopy are based on the time and spatial coherence of laser radiation. This coherence makes possible the study of the spectral-line structure usually concealed by the Doppler broadening due to the thermal motion of the gas particles.

Owing to its high monochromaticity and coherence, laser radiation causes a substantial number of particles to move from the ground state to an excited state. As a result, the sensitivity of registration of atoms and molecules is enhanced: impurities consisting of 102 atoms or 1010 molecules per cm3 of a substance can be registered. Methods are being developed for registering individual atoms and molecules.

Extremely short laser pulses are employed to investigate the rapidly occurring (~10–6–10–12 sec) processes of excitation, deex-citation, and transfer of excitation in a substance. Through the use of pulses of directional laser radiation, the scattering and fluorescence spectra of atoms and molecules in the atmosphere can be studied at substantial distances (-100 km), information can be obtained on the composition of the atmosphere, and environmental pollution can be monitored.

By focusing laser radiation, the composition of small amounts of a substance (with dimensions of the order of a wavelength) can be studied. This technique has been successfully applied to the analysis of local emission spectra.

The devices employed in laser spectroscopy are fundamentally different from conventional spectroscopic devices. In devices using tunable lasers there is no need to separate the radiation into a spectrum by means of dispersing elements (prisms or diffraction gratings), which are an important part of conventional spectroscopic devices. Sometimes laser spectroscopy makes use of devices in which the radiation is separated into a spectrum by means of nonlinear crystals (see Figure 3 in NONLINEAR OPTICS).


Letokhov, V. S., and V. P. Chebotaev. Printsipy nelineinoi lazernoi spektroskopii. Moscow, 1975.
Moenke, H., and L. Moenke. Vvedenie v lazernyi emissionnyi mikrospektral’nyianaliz. Moscow, 1968. (Translated from German.)
Letokhov, V. S. “Problemy lazernoi spektroskopii.” Uspekhi ftzicheskikh nauk, 1976, vol. 118, issue 2.


laser spectroscopy

[′lā·zər spek′träs·kə‚pē]
A branch of spectroscopy in which a laser is used as an intense, monochromatic light source; in particular, it includes saturation spectroscopy, as well as the application of laser sources to Raman spectroscopy and other techniques.
References in periodicals archive ?
The scientists are also working to bring laser spectroscopy under the ocean, which presents challenges because the gases they want to measure are dissolved in water.
Investigation of the processes involved through steady state photolysis and time resolved laser spectroscopy suggests the following trends (25, 26).
The subject of the order is the delivery of equipment for laser diagnostics, Ie apparatus with high-resolution laser spectroscopy for the purposes of scientific research.
Physicists and chemists describe how laser spectroscopy can be used for sensing and chemical analysis.
The other, led by Harvard University chemist Bretislav Friedrich, used laser spectroscopy to characterize this orientation.
The second half discusses various nanomaterial characterization techniques involving lasers, from Raman and photoluminescence spectroscopies to light dynamic scattering, laser spectroscopy and such unusual techniques as laser and photo acoustic, laser ultrasound, and laser-induced thermal pulses.
Contract notice: Supply of high-resolution laser spectroscopy equipment for the Institute of Electronic Materials Technology in Warsaw.
Principles of laser spectroscopy and quantum optics.
Edward Lai has made substantial contributions to the analytical chemistry of biochemical and environmental materials by using such novel techniques as nonasecond laser spectroscopy, surface plasmon resonance, time-of-flight spectrometry and electrochromatography, resulting in new photochemical, electrochemical, optical, and molecular recognition phenomena.
The application of lasers to analytical measurements varies from well-known laser spectroscopy and interferometry to lesser-known methods, such as dosimetry, adhesive-bond measurements, and thermal diffusivity.
Chapter 5 - General concepts of laser spectroscopy.
Tenders are invited for dcu wishes to invite tenders for the provision an ultrafast laser spectroscopy laboratory comprising a high repetition rate (>100 khz) femtosecond laser system, a khz amplifier system pumping an ir to mir opa and a harmonics line.

Full browser ?