Akihiko Matsuura

102.3-Tb/s (224 × 548-Gb/s) C- and extended L-band all-Raman transmission over 240 km using PDM-64QAM single carrier FDM with digital pilot tone

We demonstrate 102.3 Tb/s transmission over 3×80 km of PSCF by employing 548-Gb/s PDM-64QAM single-carrier frequency-division-multiplexing (SC-FDM) signals with pilot tone and 11.2-THz ultra-wideband low-noise amplification in the C- and extended L-bands.

100 × 120-Gb/s PDM 64-QAM transmission over 160 km using linewidth-tolerant pilotless digital coherent detection

We demonstrate 11.2-Tb/s transmission of 12.5-GHz spaced 120-Gb/s PDM 64-QAM signals over 160 km by using a digital coherent receiver with pilotless demodulation algorithms. The spectral efficiency of 9.0 b/s/Hz is the highest reported for 100-Gb/s/ch-class transmission.

Nonlinear Tolerant Spectrally-Efficient Transmission Using PDM 64-QAM Single Carrier FDM With Digital Pilot-Tone

We propose nonlinear tolerant single carrier frequency-division-multiplexing (SC-FDM) signal enhanced by digital pilot-tone for future high speed Ethernet transport like 400 G Ethernet. First, we discuss system configuration and the wavelength-division-multiplexed (WDM) transmission of SC-FDM signals employing polarization-division-multiplexed (PDM) 64-ary quadrature amplitude modulation (64-QAM). Next, we describe the long-haul transmission characteristics of 50 GHz-spaced 538 Gb/s × 7 ch WDM signals. We compare digital back-propagation (DBP) and digital pilot-tone for nonlinearity compensation and experimentally show that digital pilot-tone can effectively compensate the phase noise induced by inter-channel nonlinear effects with less computational complexity than DBP. Then we discuss a high-capacity transmission experiment employing 548 Gb/s PDM-64QAM SC-FDM; 102.3 Tb/s (224 × 548 Gb/s) C- and extended L-band WDM transmission is demonstrated over 240 km (3 × 80 km) of pure-silica-core fiber (PSCF) with all-Raman amplification. Thanks to the high nonlinear tolerance enhanced by pilot-tone, we can employ the 80 km repeater spacing used in conventional terrestrial systems. Assuming 20% forward error correction (FEC) overhead, a spectral efficiency of 9.1 b/s/Hz is achieved.

All-optical address extraction for optical routing

This paper describes the optical circuit that enables to extract address from a transmitted cell in an all-optical manner. Nonlinear optical loop mirrors (NOLMs) are used as all-optical switches in order to confirm the operation of the proposed circuit. The control pulses synchronized with address bits are generated from the transmitted cell. The address bits are successfully extracted without any electronic control circuit. The factors that limit an attainable bit rate are discussed. If we use NOLM composed of a 2-km-long fiber, 110 Gb/s is attainable for the 4 ps FWHM input pulse with RZ format.

Nonlinear tolerant long-haul WDM transmission over 1200km using 538Gb/s/ch PDM-64QAM SC-FDM signals with pilot tone

We investigate long-haul WDM transmission using 538Gb/s PDM-64QAM single-carrier frequency-division-multiplexing (SC-FDM) signal with pilot tone. Assuming 20% FEC overhead, the longest transmission distance of 1200km at the spectral efficiency of 8.96b/s/Hz is achieved.

High-order QAM transmission for spectrally-efficient and high-capacity transport

High-order QAM offers the high spectral efficiency and high capacity. PDM-64QAM with single-carrier frequency-division-multiplexing (SC-FDM) enhanced by pilot-tone-based phase noise compensation is proposed and shown to achieve high-capacity transport with 400Gb/s-class high speed channels.

43-Gbit/s OTN interface prototype

Reports, for the first time, a 43-Gbit/s OTN interface prototype that implements more system functions than optical sending/reception, such as framing, scrambling/de-scrambling, client mapping, and supervisory functions, all with high performance.

Nyquist-WDM transmission of 7 x 192 Gb/s PDM 16-QAM signals using high-speed DACs operating at 42 GS/s

We report Nyquist-wavelength-division-multiplexed (Nyquist-WDM) seven-channel 192-Gb/s polarization-divisionmultiplexed 16-QAM transmission. The transmitter comprises high-speed digital-to-analog converters (DACs) fabricated with 0.5-μm indium phosphide (InP) heterojunction bipolar transistors and an FPGA-based multi-channel digital signal generator, and enables us to perform transmitter-side digital signal processing (DSP) for spectrally efficient WDM transmission. The transmitter generated 24-Gbaud electrical waveforms for optical 16-QAM signals with a digital pre-filter. Using low-loss and low-nonlinear pure silica core fiber, we achieved 25-GHz-spaced seven-channel 192 Gb/s transmission distance of 480 km with a spectral efficiency of 7.17 b/s/Hz.

Ultra high capacity transmission based on high-order QAM for future optical transport networks

High-capacity transmission using high-order QAM enhanced by powerful DSP is being intensely investigated. In this paper, we review recent high capacity transmission approaches and propose a 400-Gb/s superchannel configuration for future OTNs.

Optical duobinary signal transmitter using optical waveform shaper with chirp reduction

We propose a novel optical duobinary signal transmitter that consists of an optical duobinary signal multiplexer (ODM) and an optical waveform shaper (OWS) which eliminates pattern-dependent chirp and waveform distortion. We verified the feasibility of the proposed transmitter by experiments.