Toshio Morioka

New generation optical infrastructure technologies: “EXAT initiative” towards 2020 and beyond

Research effort of most advanced optical infrastructure technologies named “EXAT: Extremely Advanced Transmission” towards the next few decades and beyond are described, enabling well over Peta bit/s per fiber link capacity and Exa-class network throughput.

Optical parametric loop mirror.

A novel configuration for four-wave mixing (FWM) is proposed that offers the remarkable feature of inherently separating the FWM wave from the input pump and signal waves and suppressing their background amplified stimulated emission without optical filtering. In the proposed configuration, an optical parametric loop mirror, two counterpropagating FWM waves generated in a Sagnac interferometer interfere with a relative phase difference that is introduced deliberately. FWM frequency-conversion experiments in a polarization-maintaining fiber achieved more than 35 dB of input-wave suppression against the FWM wave.

Terabit LAN with optical virtual concatenation for Grid applications with super-computers

This paper proposes an optical local area network that can transmit terabit-class bulk-data with low latency in a dynamic manner. A group of wavelengths is assigned to bulk-data transmission according to the latency requirement, and parallel WDM signals are transmitted with bit-phase synchronization mechanism after fast provisioning.

Wavelength - shift - free spectral inversion with an optical parametric loop mirror

A spectral-inversion technique with no wavelength shift is presented that utilizes a novel four-wave mixing (FWM) scheme named the optical parametric loop mirror. This scheme eliminates both the input signal wave and the nondegenerate pump waves from the FWM wave generated at the signal wavelength. The compensation of waveform distortion caused by fiber chromatic dispersion is successfully demonstrated by the proposed method.

A high SNR, 150 ch supercontinuum CW optical source with precise 25 GHz spacing for 10 Gbit/s DWDM systems

A 150 channel multi-wavelength CW optical source with precise 25 GHz spacing is successfully realized by longitudinal mode slicing of a supercontinuum spectrum. We confirm the generation of more than 150 CW channels ranging from 1530 to 1560 nm with SNRs over 28.2 dB and Q-factors over 20.8 dB which are sufficient for 10 Gbit/s multi-span DWDM transmission.

Evaluation of amount of equipment on single-layer optical path networks managing multigranularity optical paths

The authors propose novel nongrooming, optical path cross-connect (OXC), single-layer optical path (OP) networks that can route multigranularity optical paths with reduced optical switch (OSW) size. Since the multigranularity OPs are handled in one OP layer, the configuration and path administration of the OXCs become simple. The authors evaluate the network topology dependency of the network elements, i.e., the required number of OSW ports and fibers in networks consisting of 36 fixed nodes with different network topologies as well as that of a 16-OXC, 25-link NSFNET. The proposed networks require 60% fewer OSW ports, enabling efficient link resource utilization. A 60% reduction in total network cost is also confirmed.

160-gb/s adaptive dispersion equalization using an asynchronous dispersion-induced chirp monitor

This paper describes an adaptive dispersion equalizer (ADE) that uses an asynchronous dispersion-induced chirp monitor and the detailed study of the first demonstration of 160-Gb/s adaptive dispersion equalization. The device successfully equalized the dispersion change over a 40/spl deg/C temperature range (from 5/spl deg/C to 45/spl deg/C) and the dispersion slope of an 80-km dispersion-shifted fiber (DSF). The ADE will enhance the feasibility of 160-Gb/s optical transmission systems.

Large-dispersion-tolerance optical signal transmission system based on temporal imaging

A novel optical signal transmission system, which is highly tolerant of dispersion of the transmission fiber, is proposed. The system employs a dispersion fiber and a phase modulator in both the transmitter and the receiver. We analyzed the characteristics of the system, using the temporal imaging concept, and found that the output optical pulse is insensitive to dispersion of the transmission fiber if the parameters of the system are set to hold a specific condition. We report simulation results that confirm these characteristics of the proposed system.

All-optical signal processing for 160 Gbit/s/channel OTDM/WDM systems

This paper describes the state-of-the-art technologies and issues of all-optical signal processing for implementing OTDM/WDM systems with a channel bit-rate of 160 Gbit/s.

Optical frequency mixers for WDM and TDM applications

As the demand for optical fiber communications bandwidth grows, the implementation of signal processing functions using all-optical techniques becomes increasingly attractive. In recent years, a number of methods have been used to perform functions such as wavelength conversion for WDM systems, gated mixing for TDM multiplexing and demultiplexing, spectral inversion for dispersion compensation, and all-optical switching. Three-wave mixing in c(2) media is an attractive approach, presenting a combination of low pump power, wide bandwidth, and negligible degradation of signal to noise ratio. In this paper, we describe optical frequency mixers implemented using annealed proton exchanged waveguides in periodically poled lithium niobate. These devices have been used in a variety of system experiments. We present several WDM demonstrations, including wavelength conversion, dispersion compensation by mid-span spectral inversion, and compensation of Kerr nonlinearities. We also discuss TDM demonstrations such as efficient all-optical gating and multiplexing/demultiplexing of high bit-rate data streams.