A device for reducing time distortion generated in light pulses by an optical frequency converter including at least one nonlinear optical component (4) having a nonlinear optical susceptibility χ of about 2 or 3, the converter being capable of receiving at least one incident pulse light beam (2), the incident light pulses having a duration Δt0, an optical frequency ω0±Δω0 and an intensity I0(t), and of generating, by frequency conversion, at least one output pulse beam (3), the output light pulses having a duration Δt1, an optical frequency Δ1±Δω1 different from ω0±Δω0, and an intensity I1(t). The time distortion-reducing device includes a pre-compensation linear time filter (5) provided on the path of the incident beam (2), and capable of reducing the intensity time distortions generated in the frequency-converted output light pulses to at least one pre-compensation intensity Icomp.