Demonstration of Shallow Probabilistic Shaping for Low-Power Transmissions at 400 Gb/s and Beyond

Abstract

We demonstrated experimentally probabilistic shaping (PS) with a 5% increase in symbol rate for 400 Gb/s 16-ary quadrature amplitude modulation. Such a shallow PS enables significant improvement of the theoretical performance with limited incremental power consumption, peak-to-average power ratio (PAPR), and kurtosis. The PS signal was transmitted over a typical terrestrial link at a 0.8 dB larger Q margin than with uniform signaling. There were no excessive penalties such as transceiver and fiber nonlinearities because of the limited PAPR and kurtosis. Throughout an 8-hour nonlinear transmission test, there was no significant performance variation, and no residual errors after forward error correction decoding.