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CO2-laser gas discharges in narrow gaps

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Abstract

We have studied RF discharges as excitation mechanisms for distributed feedback (DFB) CO2 lasers. For CO2 laser plasmas the reduced electric fieldE/N has to be in a well-defined range. The reduced electric fieldsE/N of gas discharges in the narrow gaps with widths of the order of 100 μm required for DFB are considerably above this range. In order to study the feasibility of these RF-excited discharges for DFB CO2 lasers we have measured the electron temperatureT e in their plasmas. From helium-line-intensity ratios we have deduced a lower limit of the electron temperatureT e of 4eV. The observed high intensities of bands of singly ionized nitrogen indicate an even higher electron temperature, but an efficient pumping of the upper laser level is not possible with an electron temperature above 2.5 eV.

We have estimated the electron densityn e and the current densityj e from ratios of the intesities of forbidden and allowed helium lines. The high current densityj e is in the range of abnormal glow discharges.

In the gas discharges between narrow gaps the electron oscillation amplitudex e is large than the electrode separationd. In order to replace the resulting high electron losses a high electron temperatureT e is necessary to sustain the gas discharge. Because of this high electron temperatureT e an efficient pumping of the upper laser level is not possible.

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References

  1. H. Kogelnik, C.V. Shank: Appl. Phys. Lett.18, 152–154 (1971)

    Google Scholar 

  2. M. Nakamura, A. Yariv, H.W. Yen, S. Somekh, H.L. Garvin: Appl. Phys. Lett.22, 515–516 (1973)

    Google Scholar 

  3. R.O. Miles: Characteristics of a Distributed Feedback Carbon Dioxide Laser; Ph.D. Thesis, University of Utah, Salt Lake City (1978)

    Google Scholar 

  4. R.O. Miles, R.W. Grow: IEEE J. QE-17, 1071–1074 (1981)

    Google Scholar 

  5. E. Affolter, F.K. Kneubühl: Phys. Lett.74 A, 407–408 (1979)

    Google Scholar 

  6. E. Affolter, F.K. Kneubühl: IEEE J. QE-17, 1115–1122 (1981)

    Google Scholar 

  7. E.A.J. Marcatili, R.A. Schmeltzer: Bell Syst. Tech. J.43, 1783–1809 (1964)

    Google Scholar 

  8. H. Steffen, F.K. Kneubühl: IEEE J. QE-4, 992–1008 (1968)

    Google Scholar 

  9. D. Marcuse: IEEE J. QE-8, 661–669 (1972)

    Google Scholar 

  10. R.E. Collin:Field Theory of Guided Waves. McGraw-Hill, New York 1960) p. 477

    Google Scholar 

  11. B. Adam, F.K. Kneubühl: Appl. Phys.8, 281–291 (1975)

    Google Scholar 

  12. F.K. Kneubühl, E. Affolter: Infrared and Submillimeter-Waves Waveguides in Lasers, inInfrard and Millimeter Waves, Vol. 1, ed. by K.J. Button (Academic, New York 1979) pp. 235–278

    Google Scholar 

  13. J.J. Burke: Appl. Opt9, 2444–2452 (1970)

    Google Scholar 

  14. H.Nishihara, T. Inoue, I. Koyama: Appl. Phys. Lett.25, 391–393 (1974)

    Google Scholar 

  15. R.O. Miles, R.W. Grow: IEEE J. QE-14, 275–283 (1978)

    Google Scholar 

  16. J.E. Bjorkhelm, C.V. Shank: IEEE J. QE-8, 833–838 (1972)

    Google Scholar 

  17. F.K. Kneubühl, E. Affolter: Distributed Feedback Gas Lasers, inInfrared and Millimeter Waves, Vol. 5, ed. by K.J. Button (Academic, New York 1982) pp. 305–337

    Google Scholar 

  18. H.P. Preiswerk, M. Lubanski, S. Gnepf, F.K. Kneubühl: IEEE J. QE-19, 1452–1455 (1983)

    Google Scholar 

  19. H.P. Preiswerk, M. Lubanski, F.K. Kneubühl: Appl. Phys. B33, 115–131 (1984)

    Google Scholar 

  20. D. Wildmann, X. Zheng, H.P. Preiswerk, F.K. Kneubühl: Int. J. Infrared mm Waves5, 537–545 (1984)

    Google Scholar 

  21. D. Wildmann, S. Gnepf, F.K. Kneubühl: Appl. Phys. B42, 129–145 (1987)

    Google Scholar 

  22. H. Kogelnik, C.V. Shank: J. Appl. Phys.43, 2327–2335 (1972)

    Google Scholar 

  23. S. Gnepf, F.K. Kneubühl: Theory on Distributed Feedback Lasers with Weak and Strong Modulation, in Infrared and Millimeter Waves, Vol. 16, ed. by K.J. Button (Academic, New York 1984) Chap. 2

    Google Scholar 

  24. S. Gnepf, F.K. Kneubühl: Int. J. Infrared mm Waves5, 667–681 (1984)

    Google Scholar 

  25. F.K. Kneubühl: Rev. Roum. Phys. (1988) (To be published)

  26. F.K. Kneubühl, M.W. Sigrist:Laser (Teubner, Stuttgart 1988) pp. 146–184

    Google Scholar 

  27. B.Z. Katsenelenbaum: Izv. Akad. Nauk SSSR (1961) [English transl.: FTD-ID(RS)T-0243-79, Foreign Technology Division, WP. AFB, Ohio, USA]

  28. N.F. Kovalev, I.M. Orlova, M.I. Petelin: Sov. Phys.-Radio Phys. Quantum Electron.11, 449–450 (1968)

    Google Scholar 

  29. G.G. Denisov, M.G. Reznikov: Sov. Phys.-Radio Phys. Quantum Electron.25, 407–413 (1983)

    Google Scholar 

  30. V.L. Bratman, G.G. Denisov, N.S. Ginzburg, M.I. Peterlin: IEEE J. QE-19, 282–296 (1983)

    Google Scholar 

  31. S. Gnepf: Private communication (1988)

  32. J. Arnesson, S. Gnepf, F.K. Kneubühl: In Proc. 1st Intl. Laser Science Conf., Dallas, TX (1985)

  33. Zs. Bor: IEEE J. QE-16, 517–524 (1980)

    Google Scholar 

  34. Zs. Bor, A. Müller: IEEE J. QE-22, 1524–1533 (1986)

    Google Scholar 

  35. A.J. Beaulieu: Appl. Phys. Lett.16, 504–505 (1970)

    Google Scholar 

  36. W. Leuthard, W. Hermann, F.K. Kneubühl: Helv. Phys. Acta57, 259–261 (1984)

    Google Scholar 

  37. T.F. Deutsch, F.A. Horrigon, R.L. Rudko: Appl. Phys. Lett.15, 88–91 (1969)

    Google Scholar 

  38. D.L. Franzen, R.J. Collins: IEEE J. QE-6 163–164 (1970)

    Google Scholar 

  39. L.A. Newman, R.A. Hart: Laser Focus23, 80–91 (1987)

    Google Scholar 

  40. P.W. Smith: Appl. Phys. Lett.19, 132–134 (1971)

    Google Scholar 

  41. T.J. Bridges, E.G. Burkhardt, P.W. Smith: Appl. Phys. Lett.20, 403–405 (1972)

    Google Scholar 

  42. D. He, C.J. Baker, D.R. Hall: J. Appl. Phys.55, 4120–4122 (1984)

    Google Scholar 

  43. P. Vivaud, D. He, D.R. Hall: Opt. Commun.56, 185–190 (1985)

    Google Scholar 

  44. G. Francis:Ionization Phenomena in Gases (Butterworth), London 1964)

    Google Scholar 

  45. B.E. Cherrington:Gaseous Electronics and Gas Lasers (Pergamon, Oxford 1979)

    Google Scholar 

  46. F. Cap:Einführung in die Plasmaphysik (Akademie-Verlag, Berlin 1970) p. 71

    Google Scholar 

  47. E.W.B. Gill, A. von Engel: Proc. R. Soc. London, Ser. A197, 107–124 (1949)

    Google Scholar 

  48. W.L. Nighan, I.H. Bennet: Appl. Phys. Lett.14, 240–243 (1969)

    Google Scholar 

  49. A.J. Demaria: InPrinciples of Laser Plasmas ed. by G. Bekefi Wiley, New York 1976)

    Google Scholar 

  50. C.B. Moore, R.E. Wood, Be-Lok Hu, J.T. Yardley: J. Chem. Phys.46, 4222–4231 (1967)

    Google Scholar 

  51. J.C. Stephenson, R.E. Wood, C.B. Moore: J. Chem. Phys.48, 4790–4791 (1968)

    Google Scholar 

  52. W.L. Nighan: Phys. Rev. A2, 1989–2000 (1970)

    Google Scholar 

  53. J.J. Lowke, A.V. Phelps, B.W. Irwin: J. Appl. Phys.44, 4664–4671 (1973)

    Google Scholar 

  54. C.J. Baker, D.R. Hall, A.R. Davies: J. Phys. D17, 1597–1606 (1984)

    Google Scholar 

  55. G.J. Schulz: inPrinciples of Laser Plasma, ed. by G. Bekefi (Wiley, New York 1976) pp. 33–88

    Google Scholar 

  56. J.G. Xin, G. Alock, D.R. Hall: J. Phys. E19, 210–212 (1986)

    Google Scholar 

  57. D. He, D.R. Hall: IEEE J. QE-20, 209–214 (1984)

    Google Scholar 

  58. D. He, D.R. Hall: J. Appl. Phys.56, 8560857 (1984)

    Google Scholar 

  59. P. Vivaud, D.R. Hall: J. Appl. Phys.57, 1757–1758 (1985)

    Google Scholar 

  60. A. von Engel:Electric Plasma: Their Nature and Uses (Taylor and Francis, London 1983) p. 142

    Google Scholar 

  61. L. Schott: InPlasma Diagnostics, ed. by W. Lochte-Holtgreven (North-Holland, Amsterdam 1968) p. 668

    Google Scholar 

  62. G. Bekefi, C. Deutsch, B. Yaakobi: InPrinciples of Laser Plasma, ed. by G. Bekefi (Wiley, New York 1976) pp. 549–641

    Google Scholar 

  63. B. Lax, D.R. Cohn: InPrinciples of Laser Plasmas, ed. by G. Bekefi (Wiley, New York 1976) p. 543

    Google Scholar 

  64. M. Baranger, B. Mozer: Phys. Rev.123, 25–28 (1961)

    Google Scholar 

  65. C.R. Vidal: Z. Naturforsch.19a, 947–967 (1964)

    Google Scholar 

  66. R. Mewe: Br. J. Appl. Phys.18, 107–118 (1967)

    Google Scholar 

  67. H.W. Drawin: Z. Naturforsch.19a, 1451–1460 (1964)

    Google Scholar 

  68. H.R. Griem:Plasma Spectroscopy (McGraw-Hill, New York 1964) p. 160

    Google Scholar 

  69. M.N. Hirsch, E. Poss, P.N. Eisner: Phys. Rev. A1, 1615–1626 (1970)

    Google Scholar 

  70. I. Gallimberti, J.K. Hepworth, R.C. Klewe: J. Phys.7, 880–898 (1974)

    Google Scholar 

  71. P.O. Clark, M.R. Smith: Appl. Phys. Lett.9, 367–369 (1966)

    Google Scholar 

  72. M.Z. Novgrodov, A.G. Sviridov, N.N. Sobolev: IEEE J. QE-7, 508–512 (1971)

    Google Scholar 

  73. J. Polman, W.J. Witteman: IEEE J. QE-6, 154–157 (1970)

    Google Scholar 

  74. G. Bekefi, S.C. Brown: J. Appl. Phys.32, 25–30 (1961)

    Google Scholar 

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Leuthard, W., Kneubühl, F.K. & Schötzau, H.J. CO2-laser gas discharges in narrow gaps. Appl. Phys. B 48, 1–20 (1989). https://doi.org/10.1007/BF00694411

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