Hitachi, Ltd.

Tsutomu Yoshiya

Satoshi Aoki

Akihiko Takase

Kazuo Yamaguchi

Katsuyuki Imoto

Kazumi Kawamoto

Atsushi Takai

Naohiko Baba

Kazuo Aoyama

Atsushi Murata

Shoji Yamada

Takashi Minato

Shinzoo Nishiyama

Kyouichi Yamamoto

A method of manufacturing an optic transmission module assures a high reliability for the module by inspecting the character of a low bit error rate (BER) of the module quickly and accurately. The module is employed in an optical communication system (light transmission system) required to cope with information communication systems that are becoming faster and faster in operation and larger and larger in capacity. Also disclosed is a system and a method for inspection of the BER character which uses a rectangular wave pulse as an interference light to calculate a degradation quantity of a signal-to-noise ratio (S/N) on the basis of a simple theory, thereby inspecting the BER character by extrapolating a case in which there is no interference light (S/X&equals;&infin; or X&equals;0) with use of a sign error rate theoretical value according to a bit error rate of a light signal measured according to the degradation quantity.

Method for manufacturing optic transmission modules and system for inspecting bit error rate characters

A two-way optical transmission system in which a plurality of light signals of wavelengths differing one from another are transmitted through a single optical fiber from one end thereof to the other end and from the other end to the one end. One or more assemblies each including an electrooptic transmitter, a dielectric thin-film filter and a rod lens and one or more assemblies each including a rod lens, a dielectric thin-film filter and an opto-electric receiver are connected to the single optical fiber at both ends thereof, respectively.

Two-way optical transmission system

Growing community of inventors

Yokohama, Japan

Tsutomu Yoshiya