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Title: Limitation of the output power of cw electric-discharge CO{sub 2} lasers

Abstract

The output power of a sealed-off tunable cw CO{sub 2} laser was optimised. The dependences of the small-signal gain for the 10P(20) line and of the output powers for different transmittances of the cavity on the discharge current were determined. The distributed loss coefficient and the saturation parameter were measured. The saturation parameter increased continuously with increase in the discharge current, leading to a mismatch between the output power and gain maxima. It was established that the principal factor limiting the output power of cw electric-discharge CO{sub 2} lasers is not an increase in the temperature of the active medium but the dissociation of CO{sub 2} molecules. When the latter is minimised in order to achieve the maximum laser power, low gas temperatures are not required. (lasers)

Authors:
 [1]
  1. B.I. Stepanov Institute of Physics, National Academy of Sciences of Belarus, Minsk (Belarus)
Publication Date:
OSTI Identifier:
21442620
Resource Type:
Journal Article
Resource Relation:
Journal Name: Quantum Electronics (Woodbury, N.Y.); Journal Volume: 29; Journal Issue: 4; Other Information: DOI: 10.1070/QE1999v029n04ABEH001472
Country of Publication:
United States
Language:
English
Subject:
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY; CARBON DIOXIDE; CARBON DIOXIDE LASERS; CURRENTS; DISSOCIATION; ELECTRIC DISCHARGES; GAIN; LASER CAVITIES; LOSSES; SIGNALS; AMPLIFICATION; CARBON COMPOUNDS; CARBON OXIDES; CHALCOGENIDES; GAS LASERS; LASERS; OXIDES; OXYGEN COMPOUNDS

Citation Formats

Nevdakh, Vladimir V. Limitation of the output power of cw electric-discharge CO{sub 2} lasers. United States: N. p., 1999. Web. doi:10.1070/QE1999V029N04ABEH001472.
Nevdakh, Vladimir V. Limitation of the output power of cw electric-discharge CO{sub 2} lasers. United States. doi:10.1070/QE1999V029N04ABEH001472.
Nevdakh, Vladimir V. Fri . "Limitation of the output power of cw electric-discharge CO{sub 2} lasers". United States. doi:10.1070/QE1999V029N04ABEH001472.
@article{osti_21442620,
title = {Limitation of the output power of cw electric-discharge CO{sub 2} lasers},
author = {Nevdakh, Vladimir V},
abstractNote = {The output power of a sealed-off tunable cw CO{sub 2} laser was optimised. The dependences of the small-signal gain for the 10P(20) line and of the output powers for different transmittances of the cavity on the discharge current were determined. The distributed loss coefficient and the saturation parameter were measured. The saturation parameter increased continuously with increase in the discharge current, leading to a mismatch between the output power and gain maxima. It was established that the principal factor limiting the output power of cw electric-discharge CO{sub 2} lasers is not an increase in the temperature of the active medium but the dissociation of CO{sub 2} molecules. When the latter is minimised in order to achieve the maximum laser power, low gas temperatures are not required. (lasers)},
doi = {10.1070/QE1999V029N04ABEH001472},
journal = {Quantum Electronics (Woodbury, N.Y.)},
number = 4,
volume = 29,
place = {United States},
year = {Fri Apr 30 00:00:00 EDT 1999},
month = {Fri Apr 30 00:00:00 EDT 1999}
}
  • Temporal measurements of laser output flux of a flowing-gas cw CO$sub 2$ electron-beam-sustainer electric discharge laser exhibit large fluctuations. The amplitude of the fluctuations varies from 20 to 100% depending on cavity pressure, unstable resonator output coupling, and discharge specific power loading. Sharp discontinuities are observed in the laser medium when output flux is extracted. Gain measurements made simultaneously with output flux extraction show large fluctuations both above and below cavity threshold. These results are consistent with a basic self-oscillation instability mechanism proposed for fast- flow cw lasers using unstable resonators. (AIP)
  • In the pressure range of 0--1300 Torr and at a temperature of 293 K, the output power of a transversely electrically excited CO/sub 2/ laser with a certain composition of CO/sub 2/--N/sub 2/--He is investigated. The influence of output coupling on the output power has been analyzed. The output power varies greatly with coupling, which is different from those at low pressure. The calculated results agree with the experiments.
  • A technique utilizing an arc plasma flow for preionizing large volumes of CO/sub 2/ laser gas mixtures is reported. With this method, stable continuous discharges to 1 atm and power loadings of 400 kW/lb/sec have been obtained using a single arc source. Gain measurements are also made as well as preliminary successful attempts at cw laser action. (AIP)
  • The output power and saturation parameter of an air-breathing electric discharge CO/sub 2/ laser are reported. An output power of 79 W was obtained with an energy-conversion efficiency of 5.1% and a specific power of 12.5 J/g. The saturation parameter of approx.30 W/cm/sup 2/ was determined by measuring the gain with and without lasing. We also discuss the influence of He- and Ar-gas addition on the output power of the present laser.
  • The recently reported high nitrogen partial pressure CW CO[sub 2] laser regime which operates without auxiliary cooling is extended to the high-nitrogen high-helium partial pressure regime with an output power one order of magnitude above the former one. Both regimes rely on an unstable glow discharge plasma with extended electrodes that presents nonperiodic voltage spikes.