Question

Mention any two applications of total internal reflection.

Hint:

Total internal reflection is not only crucial for optical fibers but is also extensively used in optical devices like periscopes and binoculars to effectively manage light reflection. The condition for total internal reflection is the angle of incidence being greater than the critical angle for the medium.

Answer 1

Total internal reflection occurs when light hits the boundary between two media at an angle greater than the critical angle and gets entirely reflected back into the denser medium. This phenomenon plays a crucial role in several important optical applications. Two common applications are: 1. Optical Fibers:
Optical fibers use total internal reflection to transmit light signals over long distances. The core of the fiber has a higher refractive index than the surrounding cladding, allowing the light to be continually reflected inside the fiber core. This process minimizes signal loss, making optical fibers ideal for telecommunications, internet data transfer, and medical endoscopy.
2. Prism in Periscopes and Binoculars:
Total internal reflection is used in the design of optical instruments such as periscopes and binoculars. In periscopes, prisms are used to reflect light through 90-degree angles without any loss of light intensity. This allows a viewer to see over obstacles by redirecting light from the scene into their eyes. Similarly, in binoculars, prisms help in the efficient reflection of light to give a clear and bright image.