Takuya Ohira

Tunable dispersion equalizer with a divided thin-film heater for 40-Gb/s RZ transmissions

We have developed tunable dispersion equalizers with a chirped fiber grating on the divided thin-film heater. The divided thin-film heater took an important role in the control of dispersion and dispersion slope. We successfully demonstrated the dispersion control from -304 to -196 ps/nm, the dispersion slope control from +100 to -300 ps/nm/sup 2/, and good performance in 40-Gb/s return-to-zero transmission by using this tunable dispersion equalizer.

An analysis of the surface of the Ni–W layer of a tungsten film coating cathode

Abstract Superior characteristics of a cathode operated with higher current density are required for achieving higher brightness and higher resolution of CRTs. An improved Sc 2 O 3 -dispersed-oxide cathode (conventional cathode) with tungsten film coating (new cathode) has been developed. The capability of the new cathode for high-current density operation is 1.8 times that of the conventional Sc 2 O 3 -dispersed-oxide cathode [1] . Investigation of W behavior as well as typical characteristics of the new cathode in CRTs have been reported. This new type of oxide-coated cathode will contribute to higher brightness and higher resolution of CRTs.

25.2 Invited Paper: Recent Trends in CRT Cathodes

Image quality of CRTs has been improved by applying new technologies of electron gun, cathodes and image screen. Recently, new types of cathodes with higher current density have been developed, and have contributed higher definition and higher brightness of CRTs. This paper reviews of the recent technical progress in CRT cathodes, which are classified into thermionic cathodes and cold cathodes. Recently studies concerned with cold cathode for CRT application has been also reported, but this review focuses on thermionic cathodes which consist of Oxide-coated cathodes and Impregnated cathodes.