42.8 Gbit/s, 4 Bits per Symbol 16-ary Inverse-RZ-QASK-DQPSK Transmission Experiment without Polmux

We present an experimental implementation of 16-ary 42.8 Gbit/s Inverse-RZ-QASK- DQPSK, using four-level inverse return-to-zero amplitude modulation with four-level differential phase modulation. We demonstrate transmission over a 75 km fibre span with only minor degradation. copy2006 Optical Society of America