Four-photon resonance parametric up-conversion of the frequency of an infrared signal in a wide-band pump field

A theoretical analysis is made of the process of parametric up-conversion of the frequency of an infrared signal involving two-photon resonance of a pump field whose spectrum is considerably wider than the widths of the atomic transition lines. It is shown that the maximum steady-state efficiency of conversion in a wideband field is only slightly different from the maximum efficiency of conversion in a regular and monochromatic field. A dynamic improvement in the conversion efficiency is possible under transient interaction conditions.