1. COMMUNICATION ENG. PROF. A.M.ALLAM
Assignment
HW2
LECTURES

2. OPTICAL FIBER COMMUNICATION SYSTEM (NETW702)
IET
ASSIGNMENT-HW2
Name :…………………………………………………………………
ID :…………………………………………………………………
1- A 62.5/125 SI fiber has core index and numerical aperture 0.21carries 1500nm around 2 cm round. Find the fraction of the power lost in turn.
2-Find the radius of curvature as the number of modes decreases 50% in GI parabolic fiber of cladding index 1.5, core radius25um and fractional index difference 0.01.
3-A graded index fiber with a parabolic index profile supports the propagation of 742 guided modes. The fiber has a numerical aperture in air of 0.3 and a core diameter of 70 µm. Determine the wavelength of the light propagating in the fiber. Further estimate the maximum diameter of the fiber which gives single-mode operation as the same wavelength.\
4-Draw the wave form of the signals for analogue and digital modulations of an optical source( LED). Then derive a formula for 3dB modulation bandwidth of the LED in terms of the carrier lifetime τ and the pulse rise time of the LED

3. solution