Nonlinear level crossing in the infrared transitions of optically pumped far infrared laser media

  • N. Sokabe
  • Y. Tamura
  • K. Matsushima
  • A. Murai


In conjunction with the Stark field induced power enhancement in optically pumped far infrared lasers, absorption transitions in a degenerate two level system under the influence of an weak static Stark field have been analyed. A third order theory to the density matrix formalism leads to zero field level crossing signals for absorption in rate equation approximation and in Doppler limit. For fast relaxation among Zeeman sublevels, the zero field level crossing signal arises from population effect. Optoacoustic measurements have been carried out on the ν5,qQ(16,8) absorption line of CH3OH which produces the familiar 119-μm laser with the CO2 9P(36) pump line. The optoacoustic absorption signals observed are well reproduced by the theoretical expression.

Key Words

Optically-pumped FIR lasers Stark effect Level crossing 


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Copyright information

© Plenum Publishing Corporation 1987

Authors and Affiliations

  • N. Sokabe
    • 1
  • Y. Tamura
    • 1
  • K. Matsushima
    • 1
  • A. Murai
    • 1
  1. 1.Department of Applied PhysicsOsaka City UniversityOsakaJapan

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