What is the primary physical phenomenon underlying the working principle of optical fibers used in high-speed telecommunications?

💡 Solution & Explanation

Optical fibers operate on the principle of total internal reflection, where light rays striking the core-cladding boundary at an angle greater than the critical angle are reflected back entirely without loss. Interference and diffraction describe wave superposition and bending rather than confinement inside guiding channels. Polarization deals with the directional restriction of electric field oscillations. Total internal reflection requires light to travel from an optically denser core medium to a rarer cladding medium.