Fibre-optic digital transmission experiment with heterodyne detection

A single-channel single-polarisation all-fibre-optic transmission system at 830 nm wavelength with transmitter laser and a heterodyne receiver with local laser, monomode fibre coupler and APD mixer has been set up. The intermediate frequency was 1.5 GHz. 8.4 Mbit/s digital signals were transmitted over 280 m of single-polarisation fibre by a subcarrier modulated baseband method.