Question

The communication using optical fibers is based on the principle of

• A. total internal reflection
• B. Brewster angle
• C. polarization
• D. resonance

Hint:

Optical fibers transmit signals by keeping light trapped inside the core using total internal reflection.

Answer 1

The Correct Option is A

Step 1: Understand how light travels in optical fiber.
Light inside the fiber core repeatedly strikes the boundary with cladding.
Step 2: Condition for trapping light.
When the angle of incidence is greater than the critical angle, the light does not refract out, instead it reflects completely.
Step 3: This phenomenon is called TIR.
This repeated total internal reflection guides light through long distances inside the fiber.
Step 4: Choose correct option.
Thus, optical fiber communication works on total internal reflection.
Final Answer:
\[ \boxed{\text{(A) total internal reflection}} \]