Two-Photon Spectroscopy in the Gas Phase

  • E. W. Schlag
Part of the NATO Advanced Study Institutes Series book series (NSSB, volume 12)


In the methods of molecular spectroscopy, molecular information of high precision can be obtained by high resolution measurements in the gas phase. Here one-photon absorption in the ultraviolet has yielded important information. Whereas one-photon absorption selects g→u parity transitions, two-photon processes select g→g transitions. Selection rules also differ in many other ways. As a consequence two-photon spectroscopy opens up the possibility of observing many new transitions in molecular spectroscopy, particularly if they are carried out in the gas phase. We here demonstrate, employing the classic example of benzene, how new transitions are uncovered and a two-photon molecular spectrum in the gas phase assigned using this new technique. It is also shown that the intensity of the laser system suffices to prepare quantum states by two-photon absorption in the collisionless gas phase. This opens up a plethora of new experimental possibilities. Lifetimes are here given as an example.


Molecular Spectroscopy Vibronic State High Resolution Measurement Ground State Frequency Prepare Quantum State 
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  1. 1.
    See, however, U. Boesl, Diplomarbeit Technische, Universität Múnchen, West Germany (1973).Google Scholar
  2. 2.
    R. M. Hochstrasser, J. E. Wessel, and H. N. Sung, J. Chem. Phys. 60, 317 (1974).ADSCrossRefGoogle Scholar
  3. 3.
    R. G. Bray, R. M. Hochstrasser, and J. E. Wessel, Chem. Phys. Letters 21, 167 (1974).ADSCrossRefGoogle Scholar
  4. 4.
    L. Wunsch, H. J. Neusser, and E. W. Schlag, “Radiationless Processes.” General Discussion Meeting, Schliersee, West Germany (1974).Google Scholar
  5. 5.
    L. Wunsch, H. J. Neusser, and E. W. Schlag, Chem. Phys. Letters 31, 433 (1975).ADSCrossRefGoogle Scholar
  6. 6.
    L. Wunsch, H. J. Neusser, and E. W. Schlag, Chem Phys. Letters 32, 210 (1975).ADSCrossRefGoogle Scholar
  7. 7.
    M. Läppert-Mayer, Ann. Physik 2, 273 (1931).CrossRefGoogle Scholar
  8. 8.
    D. M. Friedrich and W. M. McClain, to be published.Google Scholar
  9. 9.
    A. C. Albrecht, J. Chem. Phys. 33, 156–169 (1960).ADSCrossRefGoogle Scholar
  10. 10.
    B. Honig, J. Jortner, and A. Szke, J. Chem. Phys. 46, 2714 (1967).ADSCrossRefGoogle Scholar
  11. 11.
    F. Metz, Chem. Phys. Letters, in press.Google Scholar
  12. 12.
    M. Roché and H. H. Jaffé, J. Chem. Phys. 60, 1193 (1974).ADSCrossRefGoogle Scholar
  13. 13.
    J. H. Callomon, T. M. Dunn, and I. M. Mills, Phil. Trans. Roy. Soc. A 259, 499 (1966).ADSCrossRefGoogle Scholar
  14. 14.
    R. M. Hochstrasser and J. E. Wessel, Chem. Phys. Letters 24, 1 (1974).ADSCrossRefGoogle Scholar
  15. 15.
    T. W. Hansch, Appl. Opt. 11, 895 (1972).ADSCrossRefGoogle Scholar
  16. 16.
    C. S. Parmenter, Advan. Chem. Phys. 22, 365 (1972).CrossRefGoogle Scholar
  17. 17.
    K. G. Spears and S. A. Rice, J. Chem. Phys. 55, 5561 (1971).ADSCrossRefGoogle Scholar

Copyright information

© Plenum Press, New York 1976

Authors and Affiliations

  • E. W. Schlag
    • 1
  1. 1.Institut für Physikalische ChemieTechnische Universität MünchenGermany

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