13.5-Tb/s (135 × 111-Gb/s/ch) No-Guard-Interval Coherent OFDM Transmission over 6,248 km using SNR Maximized Second-order DRA in the Extended L-band

Band-divided receiver for optical wideband signal

“…In recent years, much attention has been focused on coherent receivers using digital signal processing. Some papers have reported coherent high-speed transmission with orthogonal frequency division multiplexing (OFDM) [1][2][3]. In addition, real-time implementation of coherent receivers has become one of the hot topics in the optical communication field [4,5].…”

Multi-staged nonlinear compensation in coherent receiver for 12 015 km WDM transmission of 10-ch×111 Gbit/s no-guard-interval co-OFDM

“…Furthermore, optical orthogonal frequency division multiplexing (OFDM) offers higher levels of spectral efficiency because of its compact signal spectra. These signal formats can provide 111 Gbit/s serial transmission at the WDM channel spacing of 50 GHz or less [2]. However, in a multi-levelled phase modulation format, which is associated with PDM and/or OFDM, nonlinear phase distortion induced by self-phase-modulation (SPM) and cross-phase-modulation (XPM) limits system performance.…”

“…However, in a multi-levelled phase modulation format, which is associated with PDM and/or OFDM, nonlinear phase distortion induced by self-phase-modulation (SPM) and cross-phase-modulation (XPM) limits system performance. Because of these nonlinearities, transmission distance for a 100 Gbit/s signal used to be limited to 9612 km [2].…”

“…The minimum Q-factor is improved from 8.4 to 9.7 dB, which exceeds the Q-limit of 9.1 dB with a 0.6 dB margin yielding BERs below 1 Â 10 212 with use of the ITU-T G.975.1 enhanced FEC. The Q-margin will be improved to 1.2 dB, assuming the currently available commercial 10 Gbit/s FEC techniques with a 7% overhead [2]. As a consequence, transmission distance is extended from 9612 km [2] to 12 015 km.…”

“…The Q-margin will be improved to 1.2 dB, assuming the currently available commercial 10 Gbit/s FEC techniques with a 7% overhead [2]. As a consequence, transmission distance is extended from 9612 km [2] to 12 015 km. We have experimentally shown that multi-staged reverse phase modulation paired with the split CD equalisers, each dealing with an amplifier section, successfully compensates for the SPMinduced penalty in a coherent receiver at the spectrum efficiency of 2.0 bit/s/Hz.…”