The major components of a fiber-optics cable are the core, cladding, buffer strength, strength member and the jacket.
The core is made of glass or plastic. Plastic is easier to manufacture and use but works shorter distance than glass. The core can be anywhere from about 2 to several hundred microns (1 micron = 10-6m)The core and cladding are actually manufactured as a single unit. The cladding is usually of plastic with a lower index of reflection than core.
Fiber cables are normally bundled with several cores e.g. 2, 4,6 ,8 ,12, 24, 36 or 72 (depends on manufacturing).
Different types and application
Indoor cables: Fire safety is the number one factor in selecting indoor cables, particularly those that run through plenum spaces. Indoor cables must pass the flame-retardant and smoke-inhibitor ratings specified by NEC.
Outdoor cables: Moisture resistance and temperature tolerance are the major factors when choosing materials for outdoor environment cables. They also need to be ultraviolet (UV) resistant.Aerial/Figure 8 Self-Supporting Cables: Aerial cables must endure extreme temperature ranges from sunlight heat to freezing snow. They also must survive high wind loading.