Nippon Telegraph and Telephone Corporation

Shigeru Umemura

Shigefumi Hosokawa

Tsuneo Kanai

Masao Kawachi

Akira Nagayama

Shuichiro Inagaki

Kunihiko Sasakura

Mitsuhiro Makihara

Syuichirou Inagaki

Hirobumi Kimura

Yasuo Kumakura

In an optical MDF (main distributing frame) for interconnecting external subscriber optical lines (122) with office optical lines (131) through jumpering operation, a matrix waveguide (128, 129, 130) having a plurality of crosspoints coupled with external lines and office lines is used. The matrix waveguide has a groove (235 in FIG. 4A) at each crosspoint so that said crosspoint is switched ON or OFF depending upon whether said groove is filled with matching oil or not, so that one of the external lines is connected to the selected office line. Said matching oil has the same refractive index as that of waveguides. Each crosspoint groove is coupled with a respective oil pool (236), which supplies matching oil which has essentially the same refractive index as that of a waveguide to said groove. Switching at a crosspoint is carried out in a manner that a light signal in a waveguide goes straight through the crosspoint when a groove is filled with matching oil, and the light signal changes its direction at the crosspoint through total internal reflection when the groove is empty. A jumpering operation to connect or disconnect a crosspoint is carried out by a robot (133), which fills or pulls out matching oil in the oil pool at the designated coordinates. Each external line is branched by using an optical directional coupler (237) for test purposes, and one of the branch lines subject to test is selected by using a similar 1.times.N type matrix waveguide. (FIG. 4A)

Automated optical main distributing frame system

A matrix switching device includes a matrix board and a connecting pin. X-conductor patterns are arranged in parallel with each other on one surface of the matrix board, and Y-conductor patterns are arranged in parallel with each other on the other surface. Both the patterns are arranged in a matrix form. At each crossing point of the both patterns, a through hole having conductive portions respectively connected to the X- and Y-conductor patterns and an intermediate isolation portion for interrupting conduction between the conductive portions is formed in the matrix board. The connecting pin includes conductive portions respectively electrically connected to the X- and Y-conductor patterns through the conductive portions of the through hole upon insertion of the connecting pin into the through hole.

Matrix switching device and method of manufacturing the same

Growing community of inventors

Tokyo, Japan

Shigeru Umemura