Ippei Shake

Quality monitoring of optical signals influenced by chromatic dispersion in a transmission fiber using averaged Q-factor evaluation

We evaluated the averaged Q-factor for optical signals distorted by chromatic dispersion in a transmission fiber. This letter confirms that our method has sensitivity to bit error rate degradation due to both the signal-to-noise ratio degradation of pulse distorted signals and pulse distortion itself. It also explains how fault detection in an optical network system can be done with this method.

3 Tbit/s (160 Gbit/s/spl times/19 ch) OTDM/WDM transmission experiment

3 Tbit/s (160 Gbit/s/spl times/19 channels) optical signal is successfully transmitted over 40 km dispersion-shifted fiber. Low noise supercontinuum signal pulse sources and 70 nm bandwidth tellurite-based optical amplifiers are used for 3 Tbit/s signal generation and amplification.

120 Gbit/s OTDM system prototype

A 120 Gbit/s transmission system prototype that uses optical time-division multiplexing is successfully demonstrated. Independently modulated, four 20 Gbit/s and one 40 Gbit/s channels in 120 Gbit/s signal are transmitted through a 160 km dispersion shifted fiber.

Highly Stable 160-Gb/s OTDM Technologies Based on Integrated MUX/DEMUX and Drift-Free PLL-Type Clock Recovery

This paper reports 160-Gb/s optical time-division-multiplexed (OTDM) technologies including an all-optical integrated multiplexer (MUX) providing all-channel independent modulation, an all-optical integrated demultiplexer (DEMUX) that offers all-channel simultaneous demultiplexing, and a drift-free phase-locked-loop (PLL)-type clock recovery circuit for ultrahigh-speed OTDM signals. We present the configuration of each technology and the results of experiments on those technologies. Highly stable operation is successfully demonstrated by using a MUX based on periodically-poled lithium niobate (PPLN) hybrid integrated planer lightwave circuit (PLC), a DEMUX based on semiconductor optical amplifier hybrid integrated PLC, and clock recovery circuit based on a PLL with an optical phase modulator and a PPLN waveguide

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.

Transparent and flexible performance monitoring using amplitude histogram method

The optical performance monitoring method using asynchronous amplitude histograms was introduced. Its capability to monitor both SNR and waveform distortion due to chromatic dispersion was experimentally confirmed using a 10 Gbit/s optical NRZ signal, and bit-rate flexibility from 10 to 160 Gbit/s optical RZ signal was also discussed. This method is intrinsically flexible with respect to the signal format and modulation format, and is a useful candidate for optical signal quality monitoring in optical networks in the future.

160-Gbit/s Full Channel Optical Time-Division Demultiplexer Based on SOA-Array Integrated PLC and Its Application to OTDM Transmission Experiment

This paper presents 160-Gbit/s full channel time-division demultiplexing using a semiconductor optical amplifier hybrid integrated demultiplexer on a planer lightwave circuit. Error-free demultiplexing from a 160-Gbit/s signal to 8 channel x 20Gbit/s signals is successfully demonstrated. Results of a 160-Gbit/s optical time-division-multiplexed full channel OTDM signal transmission experiment using the circuit and successful 80-km transmission are presented.

Determination of the origin of BER degradation utilizing asynchronous amplitude histograms

We propose a method that can determines the origin of BER degradation by analyzing amplitude histograms obtained by the asynchronous sampling technique. We measure asynchronous eye diagrams and evaluate both the waveform distortion caused by chromatic dispersion and the signal-to-noise ratio (SNR) deterioration by using electrical sampling to estimate the averaged Q-factor of 10 Gbit/s NRZ optical signals. Waveform distorted signals are shown to have histograms with different shape compared to signal-to-noise ratio degraded signals.

GMPLS Based Survivable Photonic Network Architecture

The objective of this paper is to survey the Generalized Multi-Protocol Label Switching (GMPLS) based recovery technology for optical transport networks. This paper introduces standardization activities of the GMPLS based recovery technology in the Internet Engineering Task Force (IETF), and recent progress of related experiments. In addition, this paper extracts requirements for the GMPLS based recovery technology through the evaluation of existing network elements, which can be client nodes of the optical transport networks. The results of field evaluations on the GMPLS based recovery technology are also introduced in this paper. Then, this paper addresses the issues for future deployment of the GMPLS based recovery technology for the optical transport networks.

Optical performance monitoring using asynchronous amplitude histogram

We report on the state of development of optical performance monitoring (OPM) method based on asynchronous amplitude histogram analysis. Accurate monitoring of noise and chromatic dispersion is demonstrated for intensity- and phase-modulated signals.