150 fs online PMD detection within 5 /spl mu/s

Abstract

Light with a low-speed polarization modulation suffers arrival time variations due to PMD (polarization-mode dispersion), detectable by integration of the VCO (voltage-controlled oscillator) input signal in the clock recovery PLL (phase locked loops). This is demonstrated in 40 Gbit/s NRZ (non RZ) and 2/spl times/40 Gbit/s RZ (return-to-zero) polarization multiplex transmission experiments.