GYFTA [non-metallic reinforcing member, loose-coated layer stranded filled, aluminum-polyethylene bonded sheathed communication outdoor optical cable] The structure of the optical cable is to insert a single-mode or multi-mode optical fiber into a high-modulus plastic with an inner filling and waterproofing. In the compound loose tube, the center of the cable core is a non-metallic strength member. For optical cables with certain core numbers, the non-metallic central strength member is extruded with a layer of polyethylene. The loose tube (and filling rope) is twisted around the central strength member into a compact and round cable core, the gap in the cable core is filled with water-blocking compound and a layer of aluminum-polyethylene sheath is extruded to form the cable.