Which term describes the layer that surrounds the core and reflects light back into it in an optical fiber?

Which term describes the layer that surrounds the core and reflects light back into it in an optical fiber?

• A. Buffer layer
• B. Cladding
• C. Strength Member
• D. Jacket

Answer: (B)

The layer that surrounds the core and keeps light from escaping by reflecting it back into the core is the cladding. In optical fibers, the cladding has a lower refractive index than the core, so light staying inside the core meets the core–cladding boundary at angles that cause total internal reflection. This keeps the light confined and guided along the fiber. The buffer layer is there mainly to protect the fiber, the strength member provides tensile support, and the jacket is the outer protective cover.

The layer that surrounds the core and keeps light from escaping by reflecting it back into the core is the cladding. In optical fibers, the cladding has a lower refractive index than the core, so light staying inside the core meets the core–cladding boundary at angles that cause total internal reflection. This keeps the light confined and guided along the fiber. The buffer layer is there mainly to protect the fiber, the strength member provides tensile support, and the jacket is the outer protective cover.