Yoshiaki Kisaka

Fast optical channel recovery in field demonstration of 100-Gbit/s Ethernet over OTN using real-time DSP

A field trial of 100-Gbit/s Ethernet over an optical transport network (OTN) is conducted using a real-time digital coherent signal processor. Error free operation with the Q-margin of 3.2 dB is confirmed at a 100 Gbit/s Ethernet analyzer by concatenating a low-density parity-check code with a OTN framer forward error correction, after 80-ch WDM transmission through 6 spans x 70 km of dispersion shifted fiber without inline-dispersion compensation. Also, the recovery time of 12 msec is observed in an optical route switching experiment, which is achieved through fast chromatic dispersion estimation functionality.

Differential precoder IC modules for over-20-Gbit/s optical duobinary transmission systems

This paper reports on precoder IC modules for 20 Gbit/s and 40 Gbit/s optical duobinary transmission systems that uses production-level 0.2 /spl mu/m gate-length GaAs MESFETs. The transmitter using the precoder module generates fully encoded 20 Gbit/s optical duobinary signals for the first time and achieves a high receiver sensitivity of -28.6 dBm.

Fully transparent multiplexing and transport of 10GbE-LANPHY signals in 44.6-Gbit/s-based RZ-DQPSK WDM transmission

Abstract: We successfully demonstrate transparent 10GbE-LANPHY transport in 44.6-Gbit/s RZ-DQPSK WDM transmission for the first time. A single-chip 43/44-Gbit/s OTN framer LSI that supports fully transparent STM-64/10GbE multiplexing and DQPSK precoding are adopted.

First- and higher-order PMD tolerance of carrier-suppressed return-to-zero format with forward error correction

The first- and higher-order PMD (polarization mode dispersion) tolerances of several line-codes with FEC are clarified experimentally. The CS-RZ format with FEC is the most robust line-code; it accepts 60% of DGD/bit-time-interval with the existence of higher-order PMD.

43-Gbit/s OTN interface prototype

Reports, for the first time, a 43-Gbit/s OTN interface prototype that implements more system functions than optical sending/reception, such as framing, scrambling/de-scrambling, client mapping, and supervisory functions, all with high performance.

Field trial of distance-adaptive optical transmission with digital in-band OSNR estimation.

We present a feasible distance-adaptive optical transmission system that selects the optimum modulation format by referencing the estimated optical signal to noise ratio (OSNR) information transmitted from an opposing transceiver via a feedback channel. A modulation format free time-domain-multiplexed pilot sequence enables OSNR estimation and feedback channel transmission. Thanks to a feedback channel transmission, this system does not need to pass through a control plane in optimizing scheme. Using this system, we demonstrated 106.6 Gb/s QPSK and 213.3 Gb/s 16 QAM distance-adaptive optical transmission in a fully automatic manner in a field-installed fiber of 70.4 to 211.2 km.

An adaptive-equalizer-less low-complexity DSP using differential code shift keying

We propose the use of differential code shift keying (DCSK) for a symbol rate adaptive low-complexity DSP algorithm by eliminating adaptive-equalizer (AEQ) with limited influence on circuit size. As a proof of concept, a 300km transmission using DCSK format was demonstrated without using AEQ.

Coherent Transmission Technologies 100Gbit/s/ch + Beyond, and its Impact to Photonic Networking

This paper reviews digital coherent transmission technologies for data rates of 100 Gbit/s/ch and beyond. It offers both application to metro/access networks and functional improvements in photonic networking.

Highly reliable 40GbE extender based on OTL3.4 parallel transmission with 1.3µm CWDM and EFEC technologies

We propose a highly reliable 40GbE extender based on OTL3.4 parallel transmission with 1.3µm CWDM and EFEC technologies. Error free transmission of a 40GbE signal over 50km SMF is successfully demonstrated.

Single-stage all-order PMD compensator using a single polarization controller

In high-speed and/or long-haul transmission systems with data rates of 40 Gbit/s and beyond, the system degradation due to 1st- and also higher-order polarization mode dispersion (PMD) is a significant issue. So far, PMD compensators have been proposed for 1st- and higher-order PMD. In this paper, we focus on two types of optical PMD compensators, single-stage first-order compensator and double-stage compensator with higher-order canceller, and estimate their performances. Moreover, we propose a single-stage first & higher-order compensator as a “degenerate” version of the double-stage one by reducing the number of monitoring parameters (circuit) and the number of controllers (PCs). The functions of 1st- and higher-order PMD compensators are integrated into a single-stage configuration, with signal distortion monitoring at the output of the polarizer. The compensation performance of three PMD compensators is investigated in a 10.7 Gbit/s NRZ transmission system. The results show that the proposed single-stage compensator can effectively suppress the degradation due to 2nd-order PMD.