Yu Mimura

Generation of in-phase pulse train from optical beat signal

We propose and demonstrate generation of an in-phase optical pulse train from an optical beat signal. The proposed method is based on four-wave mixing occurring between the two continuous waves of the beat signal and on spectral filtering to shape the spectrum to be symmetric about the carrier frequency. We perform an experiment to verify the proposed method and obtain a 1.5 ps width in-phase pulse train from a 160 GHz beat signal. Furthermore, we employ a pulse compression scheme to reshape and compress the obtained pulse train, and we show that a 160 GHz repeating, 0.7 ps FWHM, nearly transform-limited, in-phase sech pulse train is successfully generated.

Multi-core holey fibers for ultra large capacity wide-band transmission

Multi-core holey fibers for the ultra large capacity transmission were investigated numerically and experimentally. Each core can realize the ultra wide band transmission over 550-1700 nm.

Amplification characteristics of a multi-core erbium-doped fiber amplifier

A multi-core erbium-doped fiber amplifier with three cores was demonstrated. By utilizing MC-EDF with low cross-talk of -30dB, two 10-Gbit/s signals were simultaneously amplified with gain of 15dB and power penalty of less than 1dB.

Investigation of a Downsized Silica Highly Nonlinear Fiber

Theoretical influences of reducing the cladding diameter for silica highly nonlinear fiber (HNLF) have been investigated by the finite-element method. Downsized HNLF with 56-mum cladding was fabricated, and certain reliability was confirmed through mechanical and environmental tests. A coin-sized module was obtained using over 200 m of 56-mum HNLF.

Polarization insensitive arbitrary wavelength conversion in entire C-band using a PM-HNLF

Polarization insensitive pump-wavelength-tunable FWM in a zero dispersion and dispersion slope PM-HNLF was demonstrated. Polarization scrambled 10Gbit/s NRZ and DPSK signals in entire C-band were converted into entire C-band with power penalties less than 0.3dB and 0.5dB, respectively.

Multicore EDFA for DWDM transmission in full C-band

We optimize 7-multicore erbium-doped fiber amplifier for DWDM systems. Each core of MC-EDF is pumped by LD individually with bundled fan-in. The MC-EDFA has gain of 15 dB and NF of 6 dB within C-band.

Generation of 160-GHz sub-picosecond in-phase pulse train from optical beat signal

We propose a method to generate in-phase optical pulse train from optical beat signal based on four-wave mixing and asymmetric spectral filtering. A 160-GHz repeating, 0.7-ps-FWHM, nearly transform-limited, in-phase sech pulse train is successfully generated.

Stationary rescaled pulse in dispersion-managed comblike profiled fiber for highly efficient and high-quality optical pulse compression

A stationary rescaled pulse (SRP) exists in a dispersion-managed comblike profiled fiber (DM-CPF) that consists of alternate concatenations of normal-dispersion highly nonlinear fiber and single-mode fiber. Numerical analysis reveals that the newly found SRP exhibits a nearly Gaussian temporal profile with a small amount of pedestal in spite of a relatively large compression ratio. We apply the SRP propagation to optical pulse compression based on DM-CPF and demonstrate highly efficient and high-quality optical pulse compression. Using a three-step DM-CPF, we experimentally show that a 2.6 ps width input pulse is successfully compressed to a nearly Gaussian pulse having the width of 0.39 ps and the peak-to-pedestal ratio of 19.3 dB.

Compact optical pulse compressor based on comb-like profiled fiber comprised of HNLF and hole-assisted fiber

We develop a hole-assisted fiber with large anomalous dispersion and low macro-bending loss to realize compact module of CPF pulse compressor. Using the fabricated module, we demonstrate C-band wavelength-tunable pulse compression for 40 GHz pulse train

Design optimization of holey fibers to realize zero dispersion in 500 nm band and suppressed higher-order modes propagation

Design optimization of holey fiber with zero dispersion in visible region was performed. The zero dispersion wavelength was successfully shifted to 510 nm while suppressing propagation of higher-order modes.