Light pulse slowing down using backward-wave four-wave mixing

The nonlinear phase shift per unit length acquired by the transmitted and phase conjugate waves in the backward-wave four-wave mixing may be considered as the phase shift obtained because of an effective refractive index. Consequently, a spectrum of the nonlinear phase shift in non-degenerate frequency interaction corresponds to natural dispersion and such interaction may be used for temporal manipulation of light pulses. Analysis of the narrow spectrum of the nonlinear phase shift shows high potential of the backward-wave four-wave for slowing down of light pulses. The slowing down is achieved using backward-wave four-wave mixing in media with local and nonlocal response. The delay and shape transformation of output pulses are studied and compared for the transmitted and phase conjugate channels. It is shown that the phase conjugate pulse achieves a longer delay under typical experimental conditions.