Tranmission of light in optical fibre is due to

Options

A. scattering
B. diffaction
C. polarisation
D. multiple total internal reflactions

Answer

### Step-by-Step Solution

1. **Understanding Optical Fibers**: Optical fibers are specialized cables designed for transmitting light. They consist of two layers of transparent materials with different refractive indices.

2. **Refractive Indices**: In an optical fiber, the inner layer (core) has a higher refractive index (µ2) compared to the outer layer (cladding), which has a lower refractive index (µ1). This configuration is essential for the functioning of optical fibers.

3. **Incident Light Ray**: When light enters the optical fiber, it does so from the denser medium (core) to the rarer medium (cladding). The angle at which the light enters is crucial for determining whether it will be refracted or reflected.

4. **Critical Angle**: The critical angle is the angle of incidence beyond which light cannot pass into the rarer medium and is instead reflected back into the denser medium.

5. **Total Internal Reflection**:
- If the angle of incidence is less than the critical angle, the light ray will refract into the rarer medium.
- If the angle of incidence is equal to the critical angle, the refracted ray will travel along the boundary.
- If the angle of incidence is greater than the critical angle, total internal reflection occurs, and the light is reflected back into the denser medium.

6. **Multiple Reflections**: In optical fibers, light rays are designed to enter at angles greater than the critical angle, leading to multiple total internal reflections within the core. This allows the light to travel through the fiber without loss of intensity.

7. **Conclusion**: The transmission of light in optical fibers is primarily due to multiple total internal reflections, which enable efficient data transmission over long distances.

### Final Answer
The transmission of light in optical fibers is due to **multiple total internal reflections**.

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