Motoki Kakui

Raman amplification over 100 nm-bandwidth with dispersion and dispersion slope compensation for conventional single mode fiber

We realized a discrete Raman repeater with the dispersion and dispersion slope compensation over seamless bandwidth of 100 nm by using DCF. The gain flatness after transmitting the transmission line was 2.3 dBp-p, and the OSNR was from 34.5 dB to 39.3 dB. We also estimated the improvement of gain flatness by using nine wavelengths of pumping lights, and we theoretically realized the 0.5 dB gain flatness Raman amplifier.

Low-loss pure-silica-core fibers and their possible impact on transmission systems

Low-loss optical fibers are now indispensable transmission media for transmission systems. Recently, the ultralow-loss performance for long transmission systems, the water-loss-free performance for wide-band wavelength-division-multiplexing (WDM) systems, the hydrogen-loss-insensitive performance for system reliability, and the bending-loss-insensitive performance for access or indoor applications have attracted much interest. In this regard, pure-silica-core fibers (PSCFs) are suitable, and unprecedented low-loss PSCFs have been successfully fabricated. This paper introduces the recent progress of low-loss PSCFs and their possible impact on transmission systems.

Broadband discrete fiber Raman amplifier with high differential gain operating over 1.65 /spl mu/m-band

A high differential-gain (0.08 dB/mW), low-noise (<5.0 dB), broadband (30 nm) and flat-gain (</spl plusmn/1 dB) fiber Raman amplifier operating over the 1.65 /spl mu/m-band has been demonstrated employing a low-loss highly nonlinear fiber and a broadened pump light source.

Dynamic-gain-tilt-free long-wavelength band erbium doped fiber amplifiers utilizing temperature dependent characteristics of gain spectrum

By a novel automatic level control technique the thermal behavior of an EDF and the dynamic-gain-tilt of the long-wavelength band EDFA have been successfully reduced to less than O.15 dB over a 4 dB input power range.

Highly nonlinear fiber-based lumped fiber Raman amplifier for CWDM transmission systems

The highly nonlinear fiber (HNLF)-based lumped fiber Raman amplifiers (LRAs) for four- and eight-channel coarse wavelength division multiplexing (CWDM) transmission systems have been investigated. By using the developed LRA, the four-channel CWDM transmission over conventional single-mode fiber (SMF) with the length of 150 km has been successfully achieved.

Hybrid dispersion compensating Raman amplifier module employing highly nonlinear fiber

Dispersion compensating Raman amplifier with reduced power consumption has been demonstrated employing a hybrid configuration comprising DCF and highly nonlinear fiber.

3.2 Tb/s-1500 km WDM transmission experiment using 64 nm hybrid repeater amplifiers

3.2 Tb/s (160/spl times/20 Gb/s) RZ signals were transmitted over 1500 km precisely-flattened dispersion managed line with the use of newly developed 64 nm hybrid amplifiers. This is the first demonstration of multi terabit/s, long distance transmission.

Impact of double rayleigh backscattering in discrete fiber Raman amplifiers employing highly nonlinear fiber

The feasibility of discrete Raman amplifiers employing HNLF (HNLFAs) has been examined by evaluating the DRBS characteristics. The HNLFA with the DRBS crosstalk of less than 35dB is demonstrated employing the optimized configuration.

Silica-Based Bismuth-Doped Fiber for Ultra Broad Band Light Source and Optical Amplification around at 1.1mm

We have successfully developed silica-based Bismuth-doped fiber (BiDF) by using the conventional fiber fabrication technique for the first time. Fluorescence over a 150nm bandwidth is observed in the 1100nm wavelength band by using fabricated fibers.

Wavelength Dependent Gain Dynamics in Erbium-Doped Fiber Amplifiers for Multiwavelength Optical Networks

Wavelength dependence of gain dynamics is theoretically and experimentally studied for a high Al codoped EDF. The power transients change drastically according to the surviving channel wavelength. The time constant of power transients in the forward pumped hybrid EDFA seems to depend on front EDF characteristics. There is no noticeable difference in the gain excursion derivatives at the beginning of the transient response among the high Al codoped the high Al codoped EDFA and the hybrid EDFAs.