Etsushi Yamazaki

No-Guard-Interval Coherent Optical OFDM for 100-Gb/s Long-Haul WDM Transmission

This paper describes coherent optical orthogonal frequency division multiplexing (CO-OFDM) techniques for the long-haul transmission of 100-Gb/s-class channels. First, we discuss the configurations of the transmitter and receiver that implement the optical multiplexing/demultiplexing techniques for high-speed CO-OFDM transmission. Next, we review the no-guard-interval (No-GI) CO-OFDM transmission scheme which utilizes optical multiplexing for OFDM signal generation and the intradyne receiver configuration with digital signal processing (DSP). We examine the transmission characteristics of the proposed scheme, and show that No-GI CO-OFDM offers compact signal spectra and superior performance with regard to tolerance against optical amplifier noise and polarization-mode dispersion (PMD). We then introduce long-haul high-capacity transmission experiments employing No-GI CO-OFDM; 13.4 Tb/s (134 times 111 Gb/s) transmission is successfully demonstrated over 3600 km of ITU-T G.652 single-mode fiber without using optical dispersion compensation.

Fast optical channel recovery in field demonstration of 100-Gbit/s Ethernet over OTN using real-time DSP

A field trial of 100-Gbit/s Ethernet over an optical transport network (OTN) is conducted using a real-time digital coherent signal processor. Error free operation with the Q-margin of 3.2 dB is confirmed at a 100 Gbit/s Ethernet analyzer by concatenating a low-density parity-check code with a OTN framer forward error correction, after 80-ch WDM transmission through 6 spans x 70 km of dispersion shifted fiber without inline-dispersion compensation. Also, the recovery time of 12 msec is observed in an optical route switching experiment, which is achieved through fast chromatic dispersion estimation functionality.

Fiber-edge electrooptic/magnetooptic probe for spectral-domain analysis of electromagnetic field

We propose a new class of an electromagnetic-held probing scheme for microwave planar circuit diagnosis. The measurement principle is based on the electrooptic/magnetooptic effects of crystals glued at optical fiber facets. We have combined the concept of those fiber-edge probes with a fiber-optic RF spectrum analyzing system containing a continuous-wave semiconductor laser source, a fast photodetector, and an RF spectrum analyzer to realize a highly sensitive measurement equipment of local impedance. Electromagnetic-field intensity on a microstrip transmission line has been measured in the frequency domain, where voltage and current amplitudes have been independently investigated with sensitivities of 16 mV/Hz-1/2 and 0.33 mA/Hz-1/2, respectively. In addition, it has been shown that the former value can be improved to be 0.7 mV/Hz-1/2 or smaller by the resonant cavity enhancement effect.

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

By employing 111Gb/s no-guard-interval coherent OFDM and SNR maximized second-order distributed Raman amplification in the extended L-band, we demonstrate the record capacity-distance product of 84.3Petabit/s.km (13.5Tb/s × 6,248km), and also 1Tb/s transmission over 9,612km.

Compensation of Interchannel Crosstalk Induced by Optical Fiber Nonlinearity in Carrier Phase-Locked WDM System

A scheme that compensates the waveform distortion induced by nonlinear interchannel crosstalk such as four-wave mixing (FWM) and cross-phase modulation as well as self-phase modulation in phase-locked wavelength-division-multiplexing transmission systems is proposed. Reduction of FWM-induced waveform distortion by controlling the phase relationship between neighbouring channels and its cancellation by precompensation is successfully demonstrated

13.4-Tb/s (134 × 111-Gb/s/ch) no-guard-interval coherent OFDM transmission over 3,600 km of SMF with 19-ps average PMD

We demonstrate the record capacity-distance product of 48.2 Petabit/s.km by using 111-Gb/s no-guard-interval coherent OFDM with 2-b/s/Hz spectral efficiency.

100 Gbit/s All-Optical OFDM Transmission Using 4 × 25 Gbit/s Optical Duobinary Signals with Phase-Controlled Optical Sub-Carriers

This paper proposes 100-Gbit/s optical-OFDM transmission using the ODB format. An OFDM signal generated using a simple multi-carrier generator and multi-carrier modulator is successfully transmitted over a 20-km SMF and 100-km DSF without dispersion compensation.

100-Gb/s optical transport network and beyond employing digital signal processing

We overview the requirements and the enabling technologies for optical transmission systems up to 100 Gb/s and beyond. Polarization- division multiplexed quadrature phase shift keying with digital coherent detection, and fast recovery in optical channel rerouting are key technologies for 100-Gb/s long-haul systems and beyond. We review test results of a realtime 80-channel wavelength-division multiplexing transmission over 420 km of field-installed fiber. Finally, we focus on digital nonlinear compensation and pilot tone phase noise compensation as technologies for systems beyond 100 Gb/s.

Field demonstration of up to 640 gb/s (64 ch/spl times/10 gb/s) GWP switching networks with a QPM-LN wavelength converter in JGN II test bed

The first field experiment of virtual grouped-wavelength-path switching is successfully demonstrated by using polarization-independent multichannel wavelength conversion in a quasi-phase-matched lithium niobate waveguide and an 8times8 matrix switch. Contention resolution functionality is confirmed by using wavebands composed of 25GHz spaced, 8- or 64-ch, 10 Gb/s wavelength division multiplexing signals, transmitted through field-installed fibers in Japan Gigabit Network II optical test bed

1Tb/s (111Gb/s/ch × 10ch) no-guard-interval CO-OFDM transmission over 2100 km DSF

We demonstrated spectrally efficient (2-b/s/Hz) 1Tb/s DWDM transmission of 111 Gb/s no-guard-interval PDM CO-OFDM signals over DSFs with 50 GHz spacing. The record transmission distance of 2100 km in the 100-Gb/s-data-rate CO-OFDM systems was achieved.