H. Kawaguchi

Measurement of ultrafast cross-gain saturation dynamics of a semiconductor optical amplifier using two-color pump-probe technique

The gain dynamics of a multiple-quantum-well semiconductor optical amplifier with wide gain-bandwidth are measured by a two-color pump-probe technique using optical pulses with a pulse duration on the order of 100 fs. The short optical pulses are generated by selecting narrow spectral components from compressed supercontinuum optical pulses using optical filters.

Amplification and saturation properties of asymmetrical multiple quantum-well traveling wave semiconductor optical amplifiers

A numerical model for calculation of the steady state gain properties for asymmetrical multiple quantum-well travelling wave semiconductor optical amplifiers (AMQW TW SOAs) has been newly developed. This model consists from the rate equation system for carriers in each quantum well and integrated gain model. Using this model the gain spectra and saturation characteristics for a 6 AQW TW SOA is calculated. The results show the AMQW SOA has a wide bandwidth of about 137 nm and a large saturation power of -8.8 dBm at 202 mA.

All-optical time division and wavelength division demultiplexing of 160 Gbit/s OTDM signal by FWM in SOA

All-optical time and wavelength division demultiplexing is demonstrated at 160 Gbit/s using four-wave mixing (FWM) in an SOA. The time division demultiplexing is confirmed by the auto-correlation trace and wavelength division demultiplexing is confirmed by the waveforms selected by the band-pass filter.

Supercontinuum short optical pulse generation and its application to gain dynamics measurements of SOAs

Supercontinuum (SC) optical pulses at 1.5 /spl mu/m region with a spectral width of about 300 nm have been generated. By compensation of the up-chirp of the SC pulses, the pulse width has been compressed to 60 fs. We have measured the gain dynamics of wide gain-bandwidth semiconductor optical amplifiers (SOAs) using the two-color pump-probe technique with a few hundred-femtosecond optical pulses which were generated from the compressed SC optical pulses.

Effects of optical nonlinearity in picosecond optical pulse transmission over 200 km of optical fibers using a midspan optical phase conjugation

In this report, we experimentally demonstrate that mid-span optical phase conjugation(OPC) transmissions have large tolerance for the nonlinearity. We also compare the results with that in the transmission experiments using 200 km large-core SMFs and NDFs. We used a semiconductor optical amplifier (SOA) as an optical phase conjugator and 200 km of standard SMFs as a transmission line. We found that mid-span OPC has large tolerance for optical nonlinearity in the transmission line.

Time-domain numerical model for asymmetrical multiple-quantum well traveling-wave semiconductor optical amplifiers

In this paper, the new model for asymmetrical multiple-quantum well traveling-wave semiconductor optical amplifiers (AMQW SOA) is proposed. Numerical model based on this theory is realized in a computer simulator implemented in Simulink for Matlab. The dynamics in device are described by rate equations systems for electron and photon concentration in each QW. The model contains a material parameters base for all of the binary III-V semiconductor materials. It is shown that at equal amplification of signal, AMQW have more wide spectral bandwidth.

Picosecond 80-Gbit/s OTDM signal transmission over 208-km standard fiber using midspan optical phase conjugation

Summary form only given.A key device for long distance standard single-mode fiber (SSMF) transmission for an optical time division multiplexing (OTDM) signal is a high-speed optical phase conjugator (OPC) with high conversion efficiency. We report on a 3-ps 80Gbit/s OTDM signal transmission over a 208-km SSMF by using an OPC based on four-wave mixing (FWM) in SOAs.