Abstract: An optical cable having a metal tube receiving an optical fiber and bent to form a waved shape is disclosed. The optical cable may prevent cutoff of the optical fiber or deterioration of optical characteristics though tensile force is applied to the optical cable in its longitudinal direction since the metal is formed in a waved shape. To bend the metal tube, the metal tube is passed through roller pair(s) which are shaken in a direction perpendicular to the advancing direction of the metal tube. Thus, it is possible to obtain excess fiber length (EFL) easily and accurately as desired.

Abstract: A bundle tube type optical cable is disclosed. A bundle tube type optical cable comprises: a bundle of optical fiber tubes being arranged in the middle portion of the optical cable and each containing at least two optical fiber cores loosely arranged therein; a first water-blocking layer protecting the optical fiber cores in the optical fiber tube from external moisture by a water-blocking material filled in the inner space of the tube; an inner shell made of aluminum material enclosing the bundle of optical fiber tubes with a predetermined gap; a second water-blocking layer protecting the optical fiber tubes from external moisture by the water-blocking material filled in the inner space of the inner shell; and an outer sheath made of plastic material enclosing the outer surface of the inner shell.

Abstract: An optical cable having a metal tube receiving an optical fiber and bent to form a waved shape is disclosed. The optical cable may prevent cutoff of the optical fiber or deterioration of optical characteristics though tensile force is applied to the optical cable in its longitudinal direction since the metal is formed in a waved shape. To bend the metal tube, the metal tube is passed through roller pair(s) which are shaken in a direction perpendicular to the advancing direction of the metal tube. Thus, it is possible to obtain excess fiber length (EFL) easily and accurately as desired.

Abstract: The present invention relates to a tube-enclosed optical cable containing ribbon units, and more specifically to a tube-enclosed optical cable containing ribbon units which can improve the economical efficiency of the process by simplifying the manufacturing process of optical cable and at the same time can improve the water blocking capability and compression characteristics of optical cable, providing optical cable characterized by coating particularly the central member of the cable with an absorptive substance and optical cable characterized by inserting interstices coated with an absorptive substance into the empty spaces between one more tubes encircling the central member and the sheath enclosing the tubes.

Abstract: The present invention relates to a tube-enclosed optical cable containing ribbon units, and more specifically to a tube-enclosed optical cable containing ribbon units which can improve the economical efficiency of the process by simplifying the manufacturing process of optical cable and at the same time can improve the water blocking capability and compression characteristics of optical cable, providing optical cable characterized by coating particularly the central member of the cable with an absorptive substance and optical cable characterized by inserting interstices coated with an absorptive substance into the empty spaces between one more tubes encircling the central member and the sheath enclosing the tubes.