The outermost layer of a Optical Fiber cable is its protective jacket, which serves as a barrier against various environmental factors such as moisture, chemicals, and abrasion. This layer is made of heavy-duty materials, such as polyvinyl chloride (PVC), polyethylene (PE), or thermoplastic. A fiber-optic cable, also known as an optical-fiber cable, is an assembly similar to an electrical cable but containing one or more optical fibers that are used to carry light. The optical fiber elements are typically individually coated with plastic layers and contained in a protective tube. 4) Optical fiber cable twisting: twist several extruded optical fibers and strengthening units together. Types of optical cables: 1) According to the laying method, there are: self-supporting. What is the purpose of each layer of fiber optic cables? · Introduction to Fiber Optic Technology · Defining Fiber Optic Cables: An Overview · The Core: The Light Transmission Pathway · The Cladding: Refractive Properties and Light Containment · Strength Members: Ensuring Durability and Longevity ·. Twisting is the rotation of a fiber optic cable around its longitudinal axis. It can occur during installation, handling, or operation of the cable.