Polarization mode dispersion spectrum measurement via high-speed wavelength-parallel polarimetry

Abstract

We report experiments in which wavelength-parallel spectral polarimetry technology is used for measurement of the frequency-dependent polarization mode dispersion (PMD) vector. Experiments have been performed using either a grating spectral disperser, configured to provide 13.6 GHz spectral resolution over a 14 nm optical bandwidth, or a virtually imaged phased array spectral disperser, configured for 1.6 GHz spectral resolution over a 200 GHz band. Our results indicate that the spectral polarimetry data obtained via this approach are of sufficient quality to permit accurate extraction of the PMD spectrum. The wavelength-parallel spectral polarimetry approach allows data acquisition within a few milliseconds.

All-order polarisation mode dispersion compensation in 10 Gbit/s×2 Pol-Mux system via hyperfine resolution optical pulse shaping

“…A PMD emulator is constructed by concatenating over 10 polarisation maintaining fibre sections with randomly set fast axes and different lengths. From our measurements [7] shown in Fig. 2a, the differential group delay (DGD) against wavelength varies rapidly within the optical spectrum, covering a range from nearly zero to 110 ps with mean value of 41.5 ps.…”

“…The spectrum of the input signal is dispersed in free space by a virtually imaged phase array (VIPA) [8] with 200 GHz free spectral range. A polarisation insensitive beam splitter directs a portion of the signal to our fast wavelength-parallel polarimeter [7], with the remaining signal going to a 128-pixel × four-layer liquid crystal modular (LCM) array for PMD compensation [5]. The spectral dispersion across the pixels of the LCM array and of the onedimensional camera (used in PMD sensing) are carefully matched, with a value of 1.6 GHz/pixel.…”

“…The spectral dispersion across the pixels of the LCM array and of the onedimensional camera (used in PMD sensing) are carefully matched, with a value of 1.6 GHz/pixel. By using a pair of ferroelectric liquid crystal cells (FLC) [7] to sequentially transform the launch polarisation into the PMD emulator (shown in Fig. 1c) and measuring the frequencydependent polarisation of the output light for each launch, we are able to calculate the frequency-dependent Jones matrix of the emulator at each frequency sample [5,7] (only one input polarisation channel is used in the sensing step).…”

“…By using a pair of ferroelectric liquid crystal cells (FLC) [7] to sequentially transform the launch polarisation into the PMD emulator (shown in Fig. 1c) and measuring the frequencydependent polarisation of the output light for each launch, we are able to calculate the frequency-dependent Jones matrix of the emulator at each frequency sample [5,7] (only one input polarisation channel is used in the sensing step). In the compensation process the first three layers of the LCM array are programmed to generate the inverse frequency-dependent Jones matrix.…”