The module has several electro-optical elements. These are arranged in the inner chamber (65) of the module in a row in a predetermined spaced arrangement. The module has a corresponding number of lenses (51) spaced at the same distance. The module can be optically coupled to parallel optical waveguides (45) with the same spacing. The inner chamber (65) of the module is hermetically sealed by an optical window (50). The lenses (51) are integral components of the window. Preferably, the parts of the window that are without lenses are not transparent to light.
