Method of optical data transmission using polarization division multiplexing

Optical transmission device, comprising

• a signal processing unit, adapted to
• receive a first time-discrete data signal and a second time-discrete data signal at a same sampling rate,
• generate a third time-discrete data signal and a fourth time-discrete data signal at said sampling rate, using said first data signal and said second data signal, such that said first data signal and said second data signal are delayed to each other by a delay time that is variable over time at a variation frequency that is significantly smaller than said sampling rate using at least two delay elements, and
• an optical modulation unit, adapted to
• modulate the phase of a first optical signal, said signal having a wavelength and a first polarization state, in dependence on said third data signal, and to
• modulate the phase of a second optical signal, said signal having said wavelength and a second polarization state, in dependence on said fourth data signal, and
• an optical interface, adapted to transmit the first and the second modulated optical signal into an optical fibre, such that said first polarization state of said first modulated optical signal is orthogonal to said first polarization state of said second modulated optical signal,
• wherein said first time-discrete data signal and said second time-discrete data signal contribute to said third time-discrete data signal,
• and wherein said first time-discrete data signal and said second time-discrete data signal contribute to said fourth time-discrete data signal.