SRM University 2007 B.Tech Electronics and Communications Engineering Bank Optical Networks - Question Paper

S.R.M. University
Faculty of Engineering and Technology
School of Electronics and Communication Engineering

ques. Bank
Subject Code : EC459
Subject Name : Optical Networks
Class : IV Year B.Tech (ECE)

Unit – I – Fiber and Network Components
Part – A

1. Draw a block diagram of a fiber communication system.
2. Why fiber-optic communication is considered as the backbone of modern telecommunications?
3. What are the advantages of fiber optic communication?
4. What are the disadvantages of fiber optic communication?
5. Define the term wavelength and frequency.
6. Define the term refractive index.
7. Describe the functions of core and cladding in an optical fiber. Why are their refractive index is different? Which 1 has to be greater and why?
8. List the advantages of fiber optic communications over the kinds of communication technologies.
9. Why is it necessary to meet the total internal reflection requirement inside an optic fiber?
10. What is an acceptance angle? Why do we need to know what this angle is?
11. What is attenuation in an optical fiber? What is loss in an optical fiber?
12. List the major causes of attenuation in an optical fiber and discuss their mechanisms.
13. Express the pulse spreading time caused by modal dispersion in terms of the relative refractive Index ?.
14. Consider the modal dispersion for a step index multimode fiber with NA = 0.200 and n1 = 1.486. Evaluate pulse spreading per one km length.
15. Consider the model dispersion for a step index multimode fiber NA=0.200 and n1=1.486. compute the maximum number of bits/sec that can be transmitted over one km.
16. Calculate the pulse spreading due to modal dispersion and the max. no. of bits/sec that can be transmitted over 1km with a step index fiber whose parameters are provided as : n1=1.4513, n2=1.4468.
17. What are the solutions to the modal dispersion problem?
18. What is chromatic dispersion?
19. compute the pulse spreading due to chromatic dispersion for the graded index fiber if the operating wavelength is 850nm, distance is 5km and the source’s spectral width is 70nm.
20. What are bandwidth and bit rate in communication systems?
21. What is the difference ranging from dispersion and distortion?
22. Define Bandwidth. Why are electrical and optical bandwidths are different?
23. What is the relation ranging from bit rate and bandwidth.
24. Calculate the pulse spread caused by material dispersion if ?x=0.5nm, L=1km and wavelength 1550nm.
25. Calculate the pulse spread caused by waveguide dispersion if ?x=0.5nm, L=1km and wavelength 1550nm.
26. What does the term ‘State of Polarization’, mean?
27. Write the difference ranging from SPM and XPM Phenomenon
28. What is 4 Wave Mixing?
29. Why FWM is so important in today’s optical network?
30. Write the difference ranging from SRS and SBS.

Earning:   Approval pending.