Kunio Kokura

Dispersion compensating fiber used as a transmission fiber: inverse/reverse dispersion fiber

This paper gives an overview of IDF/RDF fiber design and development for submarine system. It starts with the concept of dispersion management line and its difference from the conventional DCF used in a module. Then it reviews the fiber design details and optical properties of various types of fibers used as parts of dispersion management lines. Fiber splicing issues using MFD expanding method and a brief summary of transmission experiments using the dispersion management lines are also included. Finally, we discussed a medial dispersion alternative comprising a positive and negative medial dispersion fiber and future optical properties improvements possibilities.

New type of dispersion management transmission line with MDF/sup SD/ for long-haul 40 Gb/s transmission

New type of optical links, (medial dispersion fibre) MDF/sup SD/, were successfully developed both in positive and negative sign. Accumulated dispersion was suppressed about the same level with conventional NZ-DSF. Total attenuation was 0.200 dB/km and PMD 0.03 ps/rkm, so these fibers are very advantageous for 40 Gb/s transmission. Dispersion was within 0.4 ps/nm/km and attenuation was lower than 0.225 dB/km from 1500 nm to 1620 nm. And we also confirmed to be able to enlarge Aeff as 100 and 40 /spl mu/m/sup 2/ respectively by computer simulation.

Long wavelength hermetically coated fiber

A piece of carbon coated fiber more than 70 km long was obtained from a large VAD preform that showed fatigue parameter n > 200 and no loss increase due to hydrogen permeation after exposure to a hydrogen environment.