Giuseppe Marone

Coherent Transmission With Polarization Modulation: Experimental Results And System Analysis

The polarization modulation technique with two different detection schemes is analyzed. A first experimen-tal test for demonstrating the principle of differential heterodyne detection has been performed. Many computer simulations at high and low bit-rates yield a performance complete equality of the two systems.

Optical Heterodyne Communications With Polarization Modulation

The heterodyne systems with polarization modulation presented so far are reviewed both from the theoreti-cal and experimental viewpoint. The probability distribution for the basic schemes is determined through a rigorous derivation. Consequently the detection sensitivity for these particular cases is shown equal to that of FSK (although with reduced bandwidth occupancy) . This fundamental equivalence is also extended in a qualitative way to all the configurations using orthogonal polarization vectors for modulation. Open problems regarding the analy-sis of advanced versions and the development of numerical simulations are also discussed in detail.

Polarization modulation with frequency shift redundancy and frequency modulation with polarization redundancy for POLSK and FSK systems

Digital switching of the state of polarization (SOP) has been proposed in optical coherent communications for either polarization-independent or SOP-coded transmissions. In both cases external SOP modulators with high insertion losses have been employed. To avoid this penalty, the use of a twin-laser module synchronously operating both in polarization and frequency shift modulation conditions is presented. The feasibility of the relevant schemes for both the aforesaid system types is demonstrated through numerical simulations at 1.55 micrometers wavelength and 155 Mbit/s bit rate.