Question

Fiber optic transmission is based on the phenomenon of:
(A) Interference
(B) Polarization
(C) Total internal reflection
(D) Photoelectric effect

Answer 1

Hint Fiber optic transmission implies a very popular and efficient concept to transfer the data or information by multiple reflections inside the optical fiber that is being used to transfer the information. You can clearly see which option seems the fittest as the answer.

Complete step by step answer:
As explained in the hint section of the solution to the asked question, the fiber optic transmission is the process of multiple internal reflections inside the optical fiber which is being used to transmit the information through them across two points or places. This can be applied most efficiently using the concept of total internal reflection, in which we experience the least data-loss and it is the most efficient method to transmit information across two points or places since very little information is permitted to go out from the optical fiber. The concept of the total internal reflection says that if the medium on the outer side has a higher refractive index, or is denser, then for a certain angle, no light rays will be refracted and all of the rays will undergo reflection and the surface of contact of the two mediums will acts as a perfect mirror and not as a surface which lets refraction happen. That particular angle is called the critical angle. We try to make the rays incidence at the surface at at least the critical angle to make the total internal reflection happen. This also confirms that all the following interactions of the rays inside the fiber will all be total internal reflection and no information will be lost until and unless the rays come out of the other mouth of the fiber.

Option C is correct answer

Note Many students will assume that this happens since the light is polarized to have less energy or intensity when going inside the fiber and just before coming out will be depolarized, but it doesn’t happen so as even if you fix the polarization angle of the rays, you cannot bring back the lost energy.