title: Ultra-dense WDM-PON delivering carrier-centralized Nyquist-WDM uplink with digital coherent detection.
abstract: We introduce an "ultra-dense" concept into next-generation WDM-PON systems, which transmits a Nyquist-WDM uplink with centralized uplink optical carriers and digital coherent detection for the future access network requiring both high capacity and high spectral efficiency. 80-km standard single mode fiber (SSMF) transmission of Nyquist-WDM signal with 13 coherent 25-GHz spaced wavelength shaped optical carriers individually carrying 100-Gbit/s polarization-multiplexing quadrature phase-shift keying (PM-QPSK) upstream data has been experimentally demonstrated with negligible transmission penalty. The 13 frequency-locked wavelengths with a uniform optical power level of -10 dBm and OSNR of more than 50 dB are generated from a single lightwave via a multi-carrier generator consists of an optical phase modulator (PM), a Mach-Zehnder modulator (MZM), and a WSS. Following spacing the carriers at the baud rate, sub-carriers are individually spectral shaped to form Nyquist-WDM. The Nyquist-WDM channels have less than 1-dB crosstalk penalty of optical signal-to-noise ratio (OSNR) at 2 × 10(-3) bit-error rate (BER). Performance of a traditional coherent optical OFDM scheme and its restrictions on symbol synchronization and power difference are also experimentally compared and studied.
authors.affiliation: US Optics Laboratories, ZTE Inc., Morristown, NJ 07960, USA. zdong9@mail.gatech.edu
authors.forename: Ze
authors.initials: Z
authors.lastname: Dong
authors.forename: Jianjun
authors.initials: J
authors.lastname: Yu
authors.forename: Hung-Chang
authors.initials: HC
authors.lastname: Chien
authors.forename: Nan
authors.initials: N
authors.lastname: Chi
authors.forename: Lin
authors.initials: L
authors.lastname: Chen
authors.forename: Gee-Kung
authors.initials: GK
authors.lastname: Chang