M.Sc. (Electronics) (Semester-IV)(New) (CBCS) Examination, 2017
OPTICAL FIBER COMMUNICATION
Day Date: Monday, 24-04-2017 Max. Marks: 70
Time: 02.30 PM to 05.00 PM
Instructions Answer five question.
Question 1 and 2 are compulsory.
Attempt any Three from Q.3 to Q.7.
Figures to the right indicate full marks.
Q.1 Choose correct answer 08
………….. has high speed detection capability.
LED LASER
Photodiode Phototransistor
In standard optical fibers the core materials is……………..
Pure silica glass Pure plastic
Abrasion-resistant plastic material All of these
In every communication system, internal noise is due to ……
Switch and power supply transient
Spontaneous fluctuation of current
Power drift
None of these
………….. material is normally used of DFAs.
Cu SiO2
Er Non of these
Bit error rate is given by …………
Ne/Nt Ne/Bt
Ne/Tb Both a and b
Best error rate is given by ……..
Charge amplifier Trans impedance amplifier
Current amplifier Voltage amplifier
WDM …………… the capacity of optical fiber link.
Looses Increases
Decreases None of these
Optical fiber works with ……………
Principle of electro mechanism
Principle of total internal refraction
Page 2 of 2
Electro optic principle
None of these
State True or False: 06
Raman optical amplifier is based on simulated scattering.
For optical communication to occur R1 of core must be greater
than R1 of cladding.
In DWDM the operation is in O and C band.
NA nsin .
In WDM, active devices are having limited flexibility.
Pumping means external current injection.
Q2 Attempt any two: 10
Write a note on analog and digital signal.
Write a note on analog receivers.
What is acceptance angle? Derive the expression for it
Write a note on Raman amplifier. 04
Q3 Describe the elements of optical fiber communication system
and compare it with conventional electrical communication
system.
08
Write a note on graded index fiber. 06
Q4 Explain different loss mechanisms in optical fiber
communication.
08
Write a note on receiver performance and receiver sensitivity. 06
Q5 Describe the basic principle of optical amplification and write a
note on Fabry Parot amplifier.
08
Write a note on power amplifier. 06
Q6 Describe in detail architecture of EDFA. 08
Write a note on intermodal dispersion 06
Q7 With necessary block diagram describe receiver section of the
optical fiber communication.
08
Write a note on optical spectrum analyzer. 06