Question

What happens inside optical fiber?

• A. Diffraction
• B. Polarization
• C. Interference
• D. Total internal reflection

Answer 1

The correct option is D

Total internal reflection

Explanation of the correct answer:
Option D: Total internal reflection

1. When a light ray gets into a cable they are totally reflected inside the cable, and the optical fiber is dependent on this principle for its operation.
2. In an optical fiber, light travels inside bouncing on the walls of the cable.
3. Light doesn't refract outside the cable into the air.
4. As the rays are totally refracted into the cable only they are totally internally reflected inside the cable.
5. Only a small quantity of light is absorbed by the glass material.
6. Total internal reflection is the basis for how the optical fiber functions.
7. Large amounts of data can be transmitted using light rays, but there is a drawback: they move in straight lines.
8. So, exploiting this advantage will be time-consuming unless we have a long, straight line without any bends. Instead, all light beams are bent inward by the optical cables' unique architecture (using TIR).
9. Continuously moving light waves bounce off the walls of the optical fiber to convey data end-to-end.
10. Compared to using metal cables, light signals experience substantially less loss even though they degrade over longer distances depending on the material's purity.
11. The following elements make up a fiber optic relay system:
    11.1 The Transmitter – It produces the light signals and encodes them to fit to transmit.
    11.2 The Optical Fibre – The medium for transmitting the light pulse (signal).
    11.3 The Optical Receiver – It receives the transmitted light pulse (signal) and decodes them to be fit to use.
    11.4 The Optical Regenerator – Necessary for long-distance data transmission.
12. Light travels from one point of the cable to another point by total internal reflection.
    

Explanation of the incorrect options:
Option A

Diffraction:

1. Diffraction of light is defined as the bending of light around corners such that it spreads out and illuminates areas where a shadow is expected.
2. Diffraction doesn't occur in optical fiber.

Option B

Polarization:

1. Polarization can be defined as a phenomenon caused due to the wave nature of electromagnetic radiation.
2. Polarization also doesn't occur in the optical fiber.

Option C

Interference:

1. Interference is the phenomenon in which two waves superpose to form the resultant wave of the lower, higher, or same amplitude.
2. Waves don't superpose in the optical fiber. So, option C is not correct.

Hence, option D is the correct option.