Abstract: The invention relates to a light intensity modulator controlled by a "word" of n bits and an opto-electronic digital-analog converter.The modulator comprises a two-arm interferometer in whose length there is created, by opto-electrical effect, successive phase shifts controlled respectively by control bits and whose values, when the control bits are in state 1, conform to the successive powers of 2. The total phase shift obtained thus depends directly on the analog value of the control word and the emerging intensity is modulated as a function of this word. A digital-analog converter is constructed by adding a photodetector means whose output voltage depends on the analog value of the control word.