Device for optical heterodyne detection of an optical signal beam and optical transmission system provided with such a device

摘要

In an optical heterodyne detector the local oscillator unit (20) emits a circularly polarised radiation beam. This beam is mixed in the beam-combining element (40) with the elliptically polarised signal beam from the transmission fibre (10). By arranging a spun optical fibre (30) between the local oscillator unit (20) and the beam-­combining element (40), a great flexibility is achieved in the construction possibilities of the detection device.