Polarization-Insensitive Phase-Transmultiplexing and Multicasting of CSRZ-OOK and 4 $\times$ RZ-BPSK to 4 $\times$ RZ-QPSK via XPM in a Birefringent PCF

By utilizing cross-phase modulation and birefringence, we demonstrated simultaneous polarization-insensitive phase-transmultiplexing and multicasting of a single 10-Gbaud CSRZ-OOK signal and 4
$\times$
10-Gbaud RZ-BPSK signals to generate 4
$\times$
10-Gbaud RZ-QPSK signals in a photonic crystal fiber. The measured receiver sensitivity OSNR penalty at BER of
$10^{-9}$
was
$\approx$
1.8 dB, relative to the FPGA-precoded RZ-DQPSK baseline, for a randomly polarized CSRZ-OOK signal, when the launch angles of all RZ-BPSK signals were fixed at
$ \approx\!45^{\circ}$
. In addition, the OSNR of the remotely generated CSRZ-OOK signal could be degraded down to
$\approx$
34 dB/0.1 nm, before the BER performance of the phase-transmultiplexing and multicasting operation began to degrade.