Polarization Dependent Loss: How the performance penalty depends on signaling and receiver architecture

Long-haul and metro polarization-multiplexed fiber systems are impaired by polarization dependent loss (PDL) that fundamentally limits their capacity. We observe in this work that, given discrete power-limited signaling, significant gains can be achieved when signaling and channel equalization are properly addressed. More precisely, compared to a conventional processing, up to 0.8dB gain in SNR is measured for an error-free transmission at a PDL level as high as 6dB.