Concept of total internal reflection

 Total Internal Reflection:

• It  is a phenomenon that occurs when light travels from a medium with a higher refractive index to a medium with a lower refractive index and the angle of incidence is greater than the critical angle. 
• In this case, all of the light is reflected back into the first medium and does not pass through into the second medium. 
• This is due to the fact that the angle of refraction approaches 90 degrees and eventually exceeds it as the angle of incidence increases beyond the critical angle. 
• Total internal reflection is a key feature of optical fibers, which use this phenomenon to transmit light over long distances with very little loss of signal. 
• The light is trapped inside the fiber by continuously reflecting off the inner surface, only escaping through the end faces. 
• This makes optical fibers an important component of communication systems, as they can transmit information over long distances with minimal signal degradation.