Optical-fibre transmission system with polarization modulation and heterodyne coherent detection

摘要

Optical-fibre transmission system with heterodyne coherent detection, in which at the transmitting side the polarization of an optical carrier is modulated, and at the receiving side the beam resulting from the combination of the modulated beam and the beam emitted from a local oscillator (12) is split into two orthogonally-polarized components. The two optical signals are detected and sent to an electronic mixer (19a, 19b) which receives the two components and carries out a synchronous demodulation eliminating the effects of the linewidth of the source (1) and of the local oscillator (12).