Laser Spark

The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Laser Spark

 

the transition of a substance to the state of a strongly ionized hot gas—a plasma—under the action of an electromagnetic field of optical frequency. Such laser-induced breakdown is similar to microwave breakdown and was first observed in 1963 when the radiation of a powerful pulsed ruby laser was focused in air.

When the phenomenon occurs, a spark arises at the focus of the lens; the observer perceives a bright flash accompanied by a loud sound. For gases, the values of the light flux intensity in the laser beam that are needed to reach the breakdown threshold are ∼ 109-1011 watts/cm2, corresponding to an electric field strength of 106-107 volts/cm. The observation of laser sparks stimulated research on the propagation and maintenance of a gas discharge by a laser beam for the purpose of creating optical plasmatrons (seeLASER RADIATION, EFFECTS OF).

Laser sparks are also observed in condensed media when powerful laser radiation is propagated in such media. Laser sparks can cause damage to materials and optical parts in laser devices.

REFERENCES

Raizer, Iu. P. Lazernaia iskra i rasprostranenie razriadov. Moscow, 1974.
MacDonald, A. Sverkhvysokochastotnyiproboi v gazakh. Moscow, 1969. (Translated from English.)

V. B. FEDOROV

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.
References in periodicals archive ?
"Laser Spark Ignition: Laser Development and Engine Testing," Fall Technical Conference of the ASME ICE Division, Long Beach, California, USA, Vol.
(12.) Richardson, S., McMillian, M.H., Woodruff, S.D, and Mclntyre, D., "Misfire, Knock and [NO.sub.x] Mapping of a Laser Spark Ignited Single Cylinder Lean Burn Natural Gas Engine," SAE Technical Paper 2004-01-1853, 2004, doi:10.4271/2004-01-1853.
In LIBS, a laser pulse is focused onto a sample to vaporize and excite [micro]g to ng amounts of material and generate a microplasma or laser spark. Light from the spark is collected and directed to a spectrometer to produce a spectrum that is recorded.
Spectroscopic analysis of Liquids using Laser Spark. Applied Spectroscopy.
Techniques include optical emission, laser spark, Wavelength Dispersive X-Ray fluorescence (WDXRF), Energy Dispersive X-Ray Fluorescence (EDXRF), X-Ray Diffraction (XRD), and automation of spectrometers.
The radiation from the laser spark is collected with a bifurcated optical fiber connected to a dual-channel Ocean Optics mini-spectrometer (SD2000, Ocean Optics, Inc., Dunedin, FL.
The laser sparks a chemical reaction in the drug, which inflames the tumor.