Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Third-order hyperpolarizability γ in nonlinear optics

  1. Jun 8, 2006 #1
    third-order hyperpolarizability "γ" in nonlinear optics

    In nonlinear optics third-order hyperpolarizability of molecules "γ" is often measured by THG(third-harmonic generation) experiments.
    So third-order nonlinear susceptibility "X(3)" could be calculated from formula using the value of "γ".
    Note that third-order nonlinear susceptibility "X(3)" is the complex number.
    However in stimulated raman scattering experiments, the gain coefficient "g" is proportion of the imaginary part of X(3).
    My question is :
    If third-order hyperpolarizability of molecules "γ" is obtained by THG method, can this value("γ" ) be used to calculate the gain coefficient "g" from stimulated raman scattering formula?
    Is third-order nonlinear susceptibility "X(3)" calculated using the value of third-order hyperpolarizability "γ" by THG method the same with the one used in stimulated raman gain coefficient formula?
  2. jcsd
  3. Jun 9, 2006 #2
    if the THG signal is close to the resonance absorption-band of some material , the third-order nonlinear susceptibility "X(3)" will become enhanced.

    Then for the same material , in stimulated Raman experiments, if the laser frequency is also close to its resonance absorption-band (stimulated resonance Raman scattering), can the third-order nonlinear susceptibility "X(3)" of this material be enhanced?

    For cases mentioned above , May third-order nonlinear susceptibilities "X(3)" from the two experiments be the same?or be approximate?
    Last edited: Jun 10, 2006
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook