Abstract: In an optical heterodyne or homodyne receiver an optical system (140) is used in which the local oscillator beam (L) is combined with the signal beam (S). Simultaneously, these beams are split into orthogonally polarized sub-beams. For this purpose the optical system (140) comprises polarization-sensitive beam-splitting layers (141a and 141b) and neutral beam-splitting layers (142a and 142b) which function as beam-combining elements. In order to align the directions of the exit sub-beams of the signal beam (.sub.11, S.sub.12, S.sub.2, S.sub.22) and the local oscillator beam (L.sub.11, L.sub.12, L.sub.21, L.sub.22), the angles (.alpha., .beta., .gamma., .delta.) enclosed by the beam-splitting faces are chosen to be such that two angles located opposite each other have a combined magnitude of 180.degree.. This is realised by providing the layers (141a, 142b and 141b, 142a) on side faces of one prism (140a, 140b).

Abstract: An optical heterodyne or homodyne receiver comprises an integrated optical component (140) in which the local oscillator beam and the signal beam are combined and simultaneouly split into orthogonally polarized sub-beams. The optical component comprises a polarization-sensitive beam-splitting layer in a first face (141) and a second beam-splitting layer in a second face (142) which is perpendicular thereto. This second layer functions as a beam-combining element in the optical receiver and has two distinct portions (142a and 142b), one portion (142a) of which passes and reflects one state of polarization (s) to the desired extent and the other portion (142b) having this property for the other state of polarization (p).

Abstract: A ball lens connector part having low total reflections as well as a method of manufacturing such a ball lens connector part are described. The total reflections can be limited to less than -60 dB by means of the present ball lens connector part. The ball lens connector part comprises a fiber with an inclined fiber end in a tubular housing which housing further comprises a ball lens. If the ball lens comprises a flat surface, the total reflections can be lower than -80 dB. By subjecting the end of the housing to a machining treatment, the center line of the said end is moved in such a manner that it coincides with the optical axis of the emanating light beam.