OPTICAL COMMUNICATION DEVICE

摘要

PROBLEM TO BE SOLVED: To reduce the phase noise in the optical fiber communication of a long distance. SOLUTION: In an optical communication device provided with a light transmitting part 1, an optical fiber transmission path 2, an optical external modulators 5 changing polarized planes of light according to external information a light receiving part 6, the cross-sectional shape of the clad of an optical fiber to be used in the optical fiber transmission path 2 is made to be a non- circular shape which does not have parallel planes faced across the core of the fiber. The cross-sectional shape of the clad of the optical fiber is made to be a polygon having sides of 2n+1 ((n) is a natural number). Moreover, the cross-sectional shape is made non-circular and assymmetric and to be only curves. The surface of the clad of the optical fiber is made to be a roughened surface.