Optical fibre are based on

Options

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

Answer

### Step-by-Step Solution:

1. **Understanding Optical Fibers**:
Optical fibers are thin strands of glass or plastic that transmit light from one end to the other. They are widely used in telecommunications and medical applications.

2. **Principle of Operation**:
The operation of optical fibers is based on the principle of **Total Internal Reflection (TIR)**. This principle states that when light travels from a medium with a higher refractive index (core) to a medium with a lower refractive index (cladding), it will reflect back into the denser medium if the angle of incidence is greater than a certain critical angle.

3. **Refractive Indices**:
For TIR to occur, the refractive index of the core (μ1) must be greater than that of the cladding (μ2). This ensures that light can be confined within the core of the fiber.

4. **Critical Angle**:
The critical angle is the minimum angle of incidence at which total internal reflection occurs. If the angle of incidence is greater than this critical angle, the light will reflect entirely within the core.

5. **Applications of Optical Fibers**:
Optical fibers are not only used for communication but also have significant applications in the medical field, such as in endoscopy, where they help in diagnosing internal organs and detecting diseases.

6. **Conclusion**:
Therefore, we conclude that optical fibers are based on the principle of total internal reflection.

### Final Answer:
Optical fibers are based on the principle of total internal reflection (TIR).

---