High Capacity/Spectral Efficiency 101.7-Tb/s WDM Transmission Using PDM-128QAM-OFDM Over 165-km SSMF Within C- and L-Bands

We experimentally demonstrate 101.7-Tb/s transmission over 355 km spans of standard single-mode fiber (SSMF) at a net spectral efficiency of 11 b/s/Hz. A total of 370 dense wavelength-division multiplexed (DWDM) channels spanning the optical C- and L-bands spaced at 25 GHz were used. Each 25-GHz channel were subdivided into four subbands, with each subband carrying a 73.5-Gb/s orthogonal frequency-division multiplexed (OFDM) signal modulated with polarization-division-multiplexing (PDM) 128-ary quadrature amplitude modulation (QAM) at each modulated subcarrier. This experiment was enabled by digital signal processing (DSP) pre-equalization of transmitter impairments, all Raman amplification, heterodyne coherent detection, and DSP postequalization of the channel and receiver impairments, including pilot-based phase noise compensation.

I. Introduction

The rising popularity of bandwidth-demanding services such as high-definition (HD) television streaming, cloud computing, interactive HD online gaming, and file sharing between large data centers is driving increasing demand for high capacity, low latency optical transport networks (OTN). To accommodate ever increasing data rates over the finite transparent spectrum of optical fiber, optical systems have had to increase spectral efficiency (SE) by using multilevel multidimensional modulation formats. Coherent detection [1] and digital signal processing (DSP) have so far enabled the capacity of experimental systems to keep pace with the 40% annual growth in global internet traffic.