Coherent control of optical four-wave mixing by two-color ω - 3ω ultrashort laser pulses
Abstract
A theoretical investigation on the quantum control of optical coherent four-wave mixing interactions in two-level systems driven by two intense synchronized femtosecond laser pulses of central angular frequencies
ω
and
3ω
is reported. By numerically solving the full Maxwell-Bloch equations beyond the slowly-varying envelope and rotating-wave approximations in the time domain, the nonlinear coupling to the optical field at frequency
5ω
is found to depend critically on the initial relative phase
ϕ
of the two propagating pulses; the coupling is enhanced when the pulses interfere constructively in the center (
ϕ=0
), while it is nearly suppressed when they are out of phase (
ϕ=π
). The tuning of the initial absolute phase of the different frequency components of synchronously propapagating
ω
-
3ω
femtosecond pulses can serve as a means to control coherent anti-Stokes Raman scattering (CARS) processes.