We present a study of two-beam coupling energy transfer arising from electronic and nuclear (i.e., Raman) contributions to the third-order refractive nonlinearity. Calculations of transient two-beam coupling in fused silica with no free parameters agree reasonably well with experiments. Numerical calculations of two-beam coupling in a medium with a purely electronic nonlinearity modeled by a Debye-type response are presented. The calculations indicate that it should be possible, although challenging, to measure electronic two-beam coupling for response times as short as ∼0.1 fs. Experiments designed to isolate the electronic response fail to produce two-beam coupling signals but do indicate that the time scale of the electronic response is well below 1 fs.
© 2000 Optical Society of America
(190.4720) Nonlinear optics : Optical nonlinearities of condensed matter
(190.7070) Nonlinear optics : Two-wave mixing
(320.2250) Ultrafast optics : Femtosecond phenomena
(320.7110) Ultrafast optics : Ultrafast nonlinear optics
(320.7130) Ultrafast optics : Ultrafast processes in condensed matter, including semiconductors
Sylvia Smolorz and Frank Wise, "Femtosecond two-beam coupling energy transfer from Raman and electronic nonlinearities," J. Opt. Soc. Am. B 17, 1636-1644 (2000)