Yojiro Mori

TL;DR: This work demonstrates unrepeated 200-km transmission of 40-Gbit/s 16-QAM signals using a digital coherent receiver, where the decision-directed carrier-phase estimation is employed and the phase fluctuation is effectively eliminated.

TL;DR: A novel configuration of the finite-impulse-response (FIR) filter adapted by the phase-dependent decision-directed least-mean-square (DD-LMS) algorithm in digital coherent optical receivers can achieve stable adaptation of filter-tap coefficients for higher-order quadrature-amplitude modulation (QAM) signals.

TL;DR: A novel method of in-band estimation of optical signal-to-noise ratio (OSNR) using a digital coherent receiver, where OSNR is determined from second- and fourth-order statistical moments of equalized signals in any modulation format is proposed.

TL;DR: A highly scalable and compact optical-node architecture that combines the subsystemmodular optical cross-connect (OXC) and transponderbank add/drop, where multiple M × M wavelength-selective switches are effectively introduced.

TL;DR: A novel scheme, which employs a local oscillator pulsed at the subharmonic frequency of the symbol rate, enabling time-division demultiplexing of the signal at the digital coherent receiver, is proposed, which demonstrates that the new type ofdigital coherent receiver operating at 10 Gsymbol/s can demodulate the aggregate symbol rate of 160 Gsy symbol/s.