Abstract: A method of and an optical arrangement for generating a non-linear optical signal on a material excited by an excitation field, wherein with the excitation field coherent fields of first and second optical pulses of differing frequency are overlapped in the material in temporal and spatial relationship, wherein the first pulses of a first frequency are generated in a first beam of a first optical generator unit, and the second pulses of a second frequency are generated in a second beam of a second optical generator unit synchronously pumped by the first optical generator unit, wherein with the first pulses of the first frequency as a fundamental frequency pulses of a higher harmonic frequency thereof are generated and the second optical generator unit is pumped with the pulses of the higher harmonic frequency.