Final answer:
The buffer diameter of a fiber in tight buffered cables is typically 900 micrometers and it enhances the durability and flexibility of the optical fiber while minimizing signal loss.
Step-by-step explanation:
The buffer of a fiber used in tight buffered cable or cordage is typically 900 micrometers in diameter and is applied directly to the outer coating layer of the optical fiber. Optical fibers are surrounded by a cladding material which has a lower index of refraction than the core to ensure total internal reflection, critical for proper light transmission. This cladding, along with a protective layer, makes the fibers both durable and flexible. In fiber optics, light is transmitted down thin fibers of plastic or glass by applying the principle of total internal reflection. To achieve this, the material surrounding the fiber must have a refractive index lower than that inside the fiber. This design minimizes signal loss and ensures the formation of quality images at the end of transmission.