In your own words, how does total internal reflection make fiber optic messages possible?

1 answer

Total internal reflection is the phenomenon that occurs when light traveling in a medium with a higher refractive index encounters a boundary with a medium of lower refractive index at an angle greater than the critical angle. Instead of being refracted or transmitted, the light is completely reflected back into the original medium.

In the context of fiber optics, this property of total internal reflection is utilized to transmit messages in the form of light pulses along thin strands of glass or plastic called optical fibers. The inner core of these fibers has a higher refractive index than the outer cladding, ensuring that light propagating through the core stays confined within it.

To transmit a message, a light source such as a laser is used to generate intense light pulses. These pulses are then injected into one end of the fiber optic cable. Due to the principle of total internal reflection, the light pulses continuously bounce off the inner walls of the fiber core, effectively traveling along the entire length of the cable.

Throughout this journey, the light pulses are able to maintain their integrity and stay focused within the core, even when the fiber bends or twists. This high level of confinement and minimal signal loss is what makes fiber optic communication so reliable and capable of transmitting large amounts of information over long distances.

When the light pulses reach the receiving end of the fiber optic cable, they are detected by a sensor or a photodiode, which converts the light energy back into electrical signals. These signals can then be transformed into the original message or data, allowing for the transmission of information at extremely high speeds and with minimal interference or degradation.