Experimental Demonstration of Rate-Flexible Coherent PON Up to 300 Gb/s

We propose a novel rate flexible coherent passive optical network (PON) that features a low complexity burst frame detection scheme to achieve modulation format selection. The proposed burst frame detection algorithm, along with burst preamble design for different modulation formats are studied in detail. In a laboratory experiment setting, the burst frame detection method allows for an automated digital signal processing (DSP) workflow that supports a wide range of modulation formats. Using the burst detection scheme, two innovative rate-flexible coherent PON architectures have been proposed and experimentally demonstrated. One features time-division multiplexing (TDM) with three modulation formats for both downstream and upstream transmission, and the other uses optical frequency comb-based multi-wavelength source for downstream broadcasting and TDM burst with three modulation formats for upstream. In the experiments, 25-GBd dual-polarization quadrature phase shift keying (DP-QPSK), dual-polarization 16 quadrature amplitude modulation (DP-16QAM), and dual-polarization 64 quadrature amplitude modulation (DP-64QAM) modulation formats were examined. A peak data rate of up to 300 Gb/s and transmission over 50 km of fiber optic link and a split ratio of 1×32 have been achieved, with a Tx optical power of +5 dBm, and an Rx optical power of around -20 dBm.