Abstract: An electrooptical module includes a converter and at least one optical wave guide having an end optically coupled to the converter through a coupling gap. The coupling gap is filled with a first light-permeable material. A second light-impermeable material protects an electrical circuit disposed in the immediate vicinity of the converter from outside light. The second material is equivalent in its basic chemical composition to the first material, but is modified in its optical properties for the sake of impermeability to light. At least one bonding wire serving to trigger the converter passes through the first and second materials.