Comparison of set-partitioned two-polarization 16qam formats with pdm-qpsk and pdm-8qam for optical transmission systems with error-correction coding

We compare set partitioned two-polarization 16QAM formats with conventional PDM-QPSK and PDM-8QAM formats by considering error correction coding. We particularly show that 128SP- 16QAM appear as a competitive alternative to PDM-8QAM for spectrally efficient (>4 b/s/Hz) optical transmission systems using forward error-correction coding.© 2012 OSA

Intra- versus Inter-channel PMD in LinearlyCompensated Coherent PDM-PSK NonlinearTransmissions

We investigate the interaction between Kerr nonlinearity and polarization mode dispersion (PMD) in homogeneous multi-channel polarization division multiplexing coherent phase shift keying transmissions. Assuming linear distortions can be fully equalized by the coherent receiver, we concentrate the investigation on the residual nonlinear penalty. We introduce a novel simulation procedure to discriminate intra-channel PMD, i.e., PMD within the channel, from inter-channel PMD, i.e., PMD among different channels, showing their relative impact on system performance in the nonlinear regime. A simple yet effective description of intra-channel PMD is proposed, which helps identify the PMD realizations giving the best/worst performance in the nonlinear regime. We show that on average PMD improves the performance of dispersion-managed links by reducing both nonlinear interactions among signals and nonlinear phase noise, while it has no effect in non-dispersion managed links

Coherent transponder for optical PS-QPSK signals

The present document relates to optical transmission systems. In particular, the present document relates to a transmitter and/or a receiver for optical polarization switches (PS) QPSK (quadrature phase shift keying) signals. An apparatus (500) for an optical transmitter of an optical polarization switched M-PSK signal comprising a first and a second polarization, with M = 2m and m≥ 1 is described. The apparatus (500) comprises mapping means (200) configured to map, at a time instant k=1,...,K, m information bits to an M-PSK constellation point, thereby generating a first symbol at time instant k for the first polarization; assign, at the time instant k, one further information bit by generating a second symbol at time instant k for the second polarization, wherein the second symbol at time instant k corresponds to the first symbol at time instant k, or corresponds to the constellation point opposite the constellation point of the first symbol at time instant k; and repeat the mapping and assigning steps for all k=1,...,K to generate a sequence of first and second symbols for the first and second polarization, respectively. The apparatus (500) further comprises decorrelation means (501, 502) configured to decorrelate the first symbol at time instant k and the second symbol at time instant k, for all k=1,...,K

PIC-to-PIC experiment at 130Gb/s based on a monolithic transmitter using switching of prefixed optical phases and a monolithic coherent receiver

We send data from a monolithic 32.5Gbaud QPSK transmitter based on switching of prefixed phases, to a 43GHz-bandwidth integrated receiver. We demonstrate 130Gb/s bit-rate per wavelength, more than twice the rate of previous PIC-to-PIC experiments