Risato Ohhira

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With LD-pumped gain-shifted thulium-doped fiber amplifiers, polarization interleave multiplexing combined with wavelength/polarization demultiplexing for 50-GHz-spaced 40-Gb/s/ch WDM signals, and a transmission line optimization for triple-band systems, the first 10-Tb/s WDM transmission in single fiber using S-, C- and L-bands is demonstrated.
A fully integrated 40 Gb/s transmitter and receiver chipset with SFI-5 interface is implemented in a 65 nm CMOS technology and mounted in a plastic BGA package. The transmitter chip provides good jitter performance with a 40 GHz full-rate clock architecture that alleviates pattern-dependent jitter and eliminates duty cycle dependence. The measured RMS(More)
As 40Gb/s optical communication systems enter the commercial stage, the transceiver, which is a key component of these systems, requires lower power dissipation, a size reduction, and a wider frequency range to meet the requirements of several standards, such as OC-768/STM-256 (39.8Gb/s), OTU-3 (43.0Gb/s), and 4×10GbE-LANPHY (44.6Gb/s). 40Gb/s(More)
We have successfully demonstrated error-free transmission of 43-Gbit/s NRZ WDM signals over a 405-km SMF having a maximum of 15.6-ps DGD with our newly-developed equalizer. The equalizer removes fatal BER-degradations from rapidly time-variant waveform distortions
We demonstrated an ultra-low jitter clock and data recovery (CDR) circuit that covers an ultra wide frequency range from 35 Gb/s to 46 Gb/s. Our CDR has a newly developed dual input LC-VCO with a fine/coarse tuning scheme and a dual-loop architecture, which consists of a phase tracking loop and a frequency tracking loop. The CDR chip, which was made using(More)
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