Optical fibers are based on the phenomenon of

Options

A. Total internal reflection
B. Less scattering
C. Refraction
D. Less absorbtion coefficient

Answer

**Step-by-Step Text Solution:**

1. **Understanding Optical Fibers**: Optical fibers are thin strands of glass or plastic that transmit light signals over long distances. They are widely used in telecommunications and medical instruments.

2. **Components of Optical Fiber**: An optical fiber consists of two main parts:
- **Core**: The central part of the fiber where light travels. It has a higher refractive index.
- **Cladding**: The outer layer that surrounds the core and has a lower refractive index.

3. **Refractive Index**: The refractive index is a measure of how much light bends when it enters a material. In optical fibers, the core's refractive index is greater than that of the cladding.

4. **Total Internal Reflection (TIR)**: Optical fibers operate on the principle of total internal reflection. This phenomenon occurs when light traveling in a denser medium (core) hits the interface with a rarer medium (cladding) at an angle greater than the critical angle.

5. **Critical Angle**: The critical angle is defined as the angle of incidence in the denser medium (core) for which the angle of refraction in the rarer medium (cladding) is 90 degrees. If the angle of incidence exceeds this critical angle, the light is reflected back into the core instead of refracting out into the cladding.

6. **Light Propagation in Optical Fibers**: When light is incident on the core-cladding interface at an angle greater than the critical angle, it undergoes total internal reflection. This process continues as the light travels through the fiber, allowing it to transmit signals efficiently over long distances.

7. **Conclusion**: Therefore, optical fibers are based on the phenomenon of total internal reflection.

**Final Answer**: Optical fibers are based on the phenomenon of **Total Internal Reflection**.

---