All-optical Signal Processing in PDM Systems

Driven by the need for high-capacity data traffic, various approaches have been deployed to enable the network spectral efficiency and overall capacity. Among them, polarization-division-multiplexing (PDM) has been extensively investigated during last few years due to the fact that it can double the spectral efficiency and system capacity directly. Since two data channels carry the same wavelength while with orthogonal polarization states, most all-optical signal processing schemes that are used for single-polarization channels, we need find cost-effective approaches for PDM systems. We review different schemes for signal processing in PDM systems using different nonlinear elements. Recent experimental demonstration results at 10-Gb/s are discussed with various functionalities such as all-optical signal regeneration, wavelength conversion, mitigating channel degrading effects and so on.