Mikio Yagi

Field Trial of 160-Gbit/s, Polarization-Division Multiplexed RZ-DQPSK Transmission System using Automatic Polarization Control

We have successfully demonstrated a field trial of 160-Gbit/s, RZ-DQPSK polarization-division multiplexed transmission system over 214 km using automatic polarization control. Q-factors of the signals have been kept stable for more than five days.

Field Trial of All-Optical 2R Regeneration in 40-Gbit/s WDM Transmission Systems with Optical Add/Drop Multiplexing

Optical signal processing is one of essential technologies for improving the flexibility of all-optical network. Above all, recently there have been a lot of studies regarding all-optical 2R/3R regeneration technology. However, there are few studies about all-optical 2R/3R technologies that are carried out in field environment. In this paper, we report the successful results of field trials of an all-optical 2R regeneration system based on an electro-absorption modulator for 40-Gbit/s WDM transmission systems with optical add/drop multiplexing. It was made sure that by applying the all-optical 2R regeneration system to the optical add/drop multiplexer in the 320-km-long transmission systems the transmission characteristics of the express signal after 320-km transmission and those of the dropped signal at 160-km can be made nearly the same. It is quite important that the transmission characteristics are equal for both the dropped and express channel from a point of view of the system design, and the results in this paper suggests one possible solution for this matter.

Field trial of automatic chromatic dispersion compensation for 40-Gb/s-based wavelength path protection

We report the results of the field trial of generalized multiprotocol label switching-based 40-Gb/s wavelength path protection by photonic cross-connect. In the trial, an automatic chromatic dispersion (CD) compensator was applied to maintain the quality of a signal after protection operation to compensate for the residual CD along the wavelength path. From the results of the field trial, we have made sure that the automatic CD compensation system is essential for the future all-optical wavelength path network.

All-Optical 2R-Regenerative Interconnection Node for DPSK Polarization-Division Multiplexed Systems

We propose an all-optical 2R-regenerative interconnection node which is applied between wide area network and metro area network for DPSK polarization-division multiplexed systems with the functions of signal format conversion and signal quality improvement.

All-optical wavelength-path service with quality assurance by multilayer integration system

In the future all-optical network controlled by generalized multiprotocol label switching (GMPLS), the wavelength path between end nodes will change dynamically. This inevitably means that the fiber parameters along the wavelength path will also vary. This variation in fiber parameters influences the signal quality of high-speed-transmission system (bit rates over 40 Gb/s). Therefore, at a path setup, the fiber-parameter effect should be adequately compensated. Moreover, the path setup must be completed fast enough to meet the network-application demands. To realize the rapid setup of adequate paths, a multilayer integration system for all-optical wavelength-path quality assurance is proposed. This multilayer integration system is evaluated in a field trial. In the trial, the GMPLS control plane, measurement plane, and data plane coordinated to maintain the quality of a 40-Gb/s wavelength path that would otherwise be degraded by the influence of chromatic dispersion. It is also demonstrated that the multilayer integration system can assure the signal quality in the face of not only chromatic dispersion but also degradation in the optical signal-to-noise ratio by the use of a 2R regeneration system. Our experiments confirm that the proposed multilayer integration system is an essential part of future all-optical networks

Field trial of 40-Gbit/s wavelength path quality assurance using GMPLS-controlled all-optical 2R regenerator

We have successfully demonstrated a field trial of 40-Gbit/s wavelength path quality assurance by applying a GMPLS-controlled all-optical 2R regenerator that is incorporated in a multilayer integration system among GMPLS control, measurement, and data planes.

Second-order PMD compensation by all-optical regenerator based on optical parametric amplification

Second-order PMD has been successfully mitigated for 80-Gbit/s RZ-DQPSK signals by an all-optical regenerator based on optical parametric amplification. System performance comparison has been made for a conventional polarizer-based PMD compensator.