engineering recuitment GATE ECE 2023-24 Test Series Electromagnetic Theory Waveguides and Guided Waves Optical Fiber
In the optical device shown in figure it is required that light does not escape through either interface. The device is made of a low-permittivity layer (substrate) on which high permittivity layer is grown or deposited (guided layer), and on top of this, there is a cladding of low-permittivity layer.
What must be the minimum angle θ such that light does not escape the optical device?
1
30°
2
45°
3
60°
4
15°