We know that the core part of the fiber is the fiber core and the cladding, which together constitute the bare fiber to realize the transmission of the optical signal. The coating mainly provides mechanical protection to the bare fiber, and it can be divided into primary coating and secondary coating. Depending on the structure of the secondary coating, the optical fibers can be classified into tight buffered fibers, loose buffered fibers, and ribbon fibers.
Tight Buffered Fiber Optic cable
The secondary coating of the tight buffered fibers is closely attached to the primary coating, and there is no gap between the two layers, so the primary coated optical fiber cannot move freely in the secondary coating. The tight buffered fibers has the characteristics of small volume and good mechanical strength, but when the external environment changes, it is susceptible, so the temperature characteristics are poor.
Loose Buffered Fiber Optic cable
The secondary coating of the loose fiber is in contact with the primary coating, but there is a gap between the two layers, and usually filled with a water-blocking paste, so that the primary coated fiber is free to move within the secondary coating. The loose tube of loose fiber can isolate the external stress and the effect of temperature change on the fiber, and the water-blocking grease filled in the tube also plays a role in protecting and blocking the fiber, so it has better mechanical properties and temperature characteristics. However, the loose fiber has a large diameter and a relatively large space.