Keiichi Aiso

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.

Hole assisted fibers (HAFs) and holey fibers (HFs) for short-wavelength applications

HAFs and HFs (MOFs) having unique dispersion properties in near infrared and visible regime will be discussed. In particular, we focus on the dispersion control in a 1.0μm band which have gathered rapidly increasing interests for the aspects of both telecom and non-telecom applications. Furthermore, dispersion shift towards visible wavelengths using a holey fiber technology has tried and the results will be explained. Finally, we will briefly discuss about the potential usage of the MOFs for short wavelength transmission.

High Repetition-Rate Similariton Generation in Normal Dispersion Erbium-Doped Fiber Amplifiers and Its Application to Multi-Wavelength Light Sources

We design and demonstrate a high repetition-rate similariton generation system using normal dispersion fiber amplifiers (NDFAs). We numerically calculate the pulse evolution in NDFAs and clarify the condition to generate similariton pulses in a finite-length NDFA. Then we design the similariton generation system in consideration of the use of Erbium-doped fibers (EDFs) and show that a km-long fiber amplifier with low normal dispersion can generate a high repetition-rate similariton train from practical pico-second pulse sources. In the experiment, we demonstrate a 10-GHz similariton source using a 1.2-km-long EDF. For application to multi-wavelength light sources, we measure the bit-error rate of the spectrally sliced similariton, and show that it exhibits low-noise performance, which is attributed to the spectral flatness.

Erbium lanthanum co-doped fiber for L-band amplifier with high efficiency, low non-linearity and low NF

We have developed an erbium/lanthanum doped fibre (ELDF) that has high Er concentration, and which attained high efficiency without quenching. We demonstrated that the ELDF had high gain per length, low non-linearity at L-band, and low noise figure compared to conventional EDF.

Phosphate-doped transmission fiber with over 40 THz Raman-gain bandwidth

We fabricated P-doped silicate fibers, which have two Raman gain peaks at around 13 THz and 40 THz. WDM pumping by semiconductor LDs generates over 40 THz continuous gain bandwidth with two broad gain bands.