Ключевые слова: abbreviation, acronym, amplification, background, concept, conserved, distortion, efficiency, electrical systems, emission, energy, femtosecond, four wave mixing, fourwave, fourwave mixing, fwm, incoming photon, interaction, intermodulation, laser, new wavelengths, nonlinear, nonlinear process, note, optic, optical, parametric, phasesensitive, phenomenon, phrase, process, produce, radiation, spectrum, spot, standard, text, theoretical, two or three, wave mixing, waveform, wavelengths, word,