Light wave transmits in optical fiber due to1 pointFrequency modulationDoppler effectTotal internal reflectionPopulation inversion

Light wave transmits in optical fiber due to Total Internal Reflection.

Here are the steps explaining how it works:

1. An optical fiber is a flexible, transparent fiber made by drawing glass or plastic to a diameter slightly thicker than that of a human hair.

2. When light signals are passed through the optical fiber, it strikes the wall of the fiber at a certain angle.

3. If this angle is greater than the critical angle (the angle of incidence beyond which rays of light passing through a denser medium to the surface of a less dense medium are no longer refracted but totally reflected), then total internal reflection occurs.

4. Total internal reflection traps light within the core of the optical fiber, allowing it to travel down the fiber with very little loss of energy.

5. This is how light wave transmits in optical fiber. The other options like Frequency modulation, Doppler effect, and Population inversion are not related to the transmission of light in an optical fiber.