Abstract: A transmission and reception module for a bidirectional optical communication network characterized by a housing containing a laser diode, a first spherical lens for focussing the output of the laser diode on a first beam path, a second spherical lens arranged on the first beam path for focussing the light from the first lens at a focal point at which an end face of an optical fiber is positioned, a beam splitter which is at least partially transmissive to light of a first wavelength from the laser diode and partially reflective of light of a second wavelength being emitted from the fiber into a second beam path on which a detector is positioned. To improve the positioning, the first lens and the laser diode are mounted on a carrier member in a fixed relationship which enables assembling the device with less problems with maladjustment.