Optical Fiber Communication - Jun 2012

Electronics & Communication (Semester 7)

TOTAL MARKS: 100
TOTAL TIME: 3 HOURS (1) Question 1 is compulsory.
(2) Attempt any four from the remaining questions.
(3) Assume data wherever required.
(4) Figures to the right indicate full marks. 1 (a) What are the advantages of optical fiber commumnication?Expalin in detail.(6 marks) 1 (b) Explain briefly the fiber materials (7 marks) 1 (c) with a neat diagram ,expalin the photonic crystal fibers,in optical fiber communication.(7 marks) 2 (a) Expain the macro bending loss in optical fiber.(6 marks) 2 (b) expain the following terms in optical communication;
attenuation
absorption
Scatttering losses
(note:Mathmatical expression and graphs may be given wherever necessary)(7 marks) 3 (a) Give comparison between laser diode and light emitting diode.considering the various parameter.(6 marks) 3 (b) A double heterojunction InGaAsp LED emitting at a peak wavelength of 1310_nmhas radiative and non radiative recombination times of 30 and 10_ns respectivly.The drive current is 40mA.calculate the:
bulk recombination lifetime
internal quantum efficinency
Internal powerlevel.(7 marks) 3 (c) Explain the operation of avalanche photo diode with schematic diagram and seprate (7 marks) 4 (a) Expalin the example of possible Lensing schemes used to improve optical source to fiber coupling efficiency?(6 marks) 4 (b) What is fiber splicing?Expalin the fussion splicing of optical fibers with relevant diagram.(7 marks) 4 (c) What are the principle requirements of a good connector ?Explain the alignment scheme used tapered-sleeve fiber-optic connector with relvant diagram(7 marks) 5 (a) Explain the receiver sensitivity of an optical receiver.Drive an expression for receiver sensitivity.(6 marks) 5 (b) Explain the general configuaration of an eye diagram showing the defination of fundamental measurements parameter.and also explin noise margin and timing jiter parameters(7 marks) 5 (c) Expalin the operation of Burst mode receiver data pattern and signal level variation in pulses(7 marks) 6 (a) Expalin the operation of multi-channel amplitude modulation standard technique for frequency division multiplexing of N independent information bearing signals.(7 marks) 6 (b) Explain the radio-over-fiber links with a concept of a broadband wireless access network for interconnecting antenna base station with the central controlling office.(6 marks) 6 (c) Expalain the link power budget,with a relevent diagram(7 marks) 7 (a) Explain the wavelenghth division multiplexing network containg various type of optical amplifires(7 marks) 7 (b) Explain the optical Isolator with a design and operation of a polarization independent isolator mode of three mainature optical components(6 marks) 7 (c) Explian the operation of optical Add/Drop multiplexers,with a relevant diagram(7 marks) 8 (a) Explain the configuration of SONET/SDH rings,with relevant digrams(10 marks) 8 (b) Write notes on the following:
optical amplifier
High speed light wave links(10 marks)