Definitions [3]
Define critical angle for a given medium.
When a ray of light propagates from a denser medium to a rarer medium, the angle of incidence for which the angle of refraction is 90° is called the critical angle.
Definition: Critical Angle
The angle of incidence in the denser medium corresponding to an angle of refraction of 90° in the rarer medium is called the critical angle.
Definition: Total Internal Reflection
The phenomenon where light rays are completely reflected back into a medium instead of being refracted into another medium is called total internal reflection.
Important Questions [7]
- What is Numerical aperture? Explain the use of optical fibre in temperature sensor. The core diameter of a multimode step index fibre is 50 μm. The numerical aperture is 0.25.
- The core diameter of multimode step index fibre is 50 μm.The numerical aperture is 0.25. Calculate the number of guided modes at an operating wavelength of 0.75 μm.
- Difference between step index and graded index fibre. An optical fibre has a numerical aperture of 0.20 and refractive index of cladding is 1.59.
- Derive the formula for numerical aperture of step index fibre and give it’s physical significance.The N.A of of an optical fibre is 0.5 and the core refractive index is 1.54
- A Glass Material a with an Optical Fibre is Made Has a Refractive Index of 1.55. this Material is Clad with Another Material Whose Refractive Index is 1.51.
- What is Monomode and Multimode Fibre? Explain the Term V-number, Calculate the Number of Modes of a Step Index Optical Fibre of Diameter 40 𝝁𝒎 Will Transmit as Its Core and Cladding Refractive
- Draw the Block Diagram of an Optical Fibre Communication System and Explain Function of Each Block.
