A Bare Fiber

    A bare fiber, a core with its cladding surrounded by a coating-is still very sensitive to the adverse environment regardless of

how perfect the coating is . Thus , in practice, you will find a fiber only in some protective enclosure, which is called fiber-optic cable,

Since optical fiber is the main transmission medium in modern telecommunications , the cabling business should be the most prolific

sector of the fiber-optic communication industry. And it is , indeed. 

    Bare glass fibers are based on silica or other glass materials. The glass surface is susceptible to abrasion and mechanical flaws.

To protect the cable from the environment, the buffer coating or jacket fits over the core and cladding.

The diameter ranges from 250μm to 900μm, usually 250um for single mode and multimode fibers, but 400um is also very common in polarization maintaining fibers. It provides mechanical protection while allowing for flexibility in the fiber.

The buffer coating is usually made of a soft or hard plastic such as acrylic or nylon.

Kevlar is a popular choice for the jacket material. It is strong and used to bundle and protect the loose tubes or fibers in the cable.

       The bare optical fiber means it has not been coated, only with fiber optic core and cladding.

Optical signals in optical fibers are using light of the principle of total reflection.

The glass fiber is the main channel of transmission of optical signals,

the cladding is used to reflect the optical signal, and the coating is to protect the fragile core.