Question

For graded index fiber, the refractive index of the core region is:

• A. Non-uniform
• B. All of these
• C. Same at core-cladding interface
• D. Increase towards the axis of the core

Answer 1

Answer: (D)

Increase towards the axis of the core

Answer 2

A graded index fiber has a core where the refractive index is not constant. It is highest at the central axis and gradually decreases parabolically or in a similar profile as the radial distance from the axis increases. Therefore, the refractive index effectively increases as one moves towards the axis of the core. This specific non-uniform profile is what defines a graded index fiber and helps in reducing intermodal dispersion.