ABSTRACT
We introduce an improved fiber figure of merit (FoM) in order to compare different fiber types used in uncompensated links for transmission of coherently-received modulation formats. The role of fiber dispersion in enhancing system performance is shown and verified by simulations and experiments, confirming the need for the inclusion of dispersion parameter in a FoM definition allowing to compare fiber types with relevant different dispersion parameters. Applicability of the proposed FoM has been demonstrated for channel spacing from the Nyquist limit up to 5/3 the symbol rate.
Subject(s)
Computer-Aided Design , Models, Theoretical , Optical Fibers , Computer Simulation , Equipment Design , Equipment Failure Analysis , Light , Scattering, RadiationABSTRACT
We investigate the impact of channel spacing and nonlinear transmission over 120 km of standard single mode fiber for a 10 Gbit/s long-reach wavelength division multiplexed passive optical network (WDM-PON). We employed polarization division multiplexed quadrature phase shift keying (PDM-QPSK), which allowed data transmission at 3.125 GBaud, including a 25% overhead for forward error correction. To receive this spectrally efficient modulation format, a digital coherent receiver was employed, allowing for both frequency selectivity and an increased sensitivity of -45 dBm (25 photons/bit).We investigated a channel spacing as low as 5 GHz, for which the loss budget was 48.6 dB, increasing to 54.0 dB for a 50 GHz grid.
