Jawaharlal Nehru Technological University Anantapur 2011 B.E Electronics & Communication Engineering Optical communications - Question Paper

OPTICAL COMMUNICATIONS
TIME:3HOURS MARKS:80
NOTE:1)answer any 5 ques.
2)all qns carry equal marks
1.a)Draw and discuss the general communication system?
b)explain the concept of total internal reflecton.
2.a)discuss the brief about active and passive glass fiber.
b)determine the cutoff wavelength for a step index fiber to exhibit a single mode operation when core refrective index and radius are 1.46,4.5micrometre,with a relative index diff being 0.25%choose Vc=2.405
3.a)briefly discuss the internal mode dispersion.
b)write a short notes single moe fiber connectors.
4.a)with a neat sketch discuss fusion splpicing optical fibers.
b)an optical fiber has a core refractive index 1.5 ttwo length of fiber with a smooth perpenducular end faces are buttered together,assume the fiber axes are perfectly alligned,calculate the optical loss in decibels at joint when there is a smal grip b/w fiber end faces.
5.a)explain the concept of euilibrium aperture.
b)what are the measured FWHM values of the laser output beams.
6.discuss about analog receivers.
7.a)briefly discuss the link power budget with examples.
b)write a short notes on mutiplexing.
8.a)write a short notes on EYE trend.
b)explain operationa principles of WDM.

Earning:   Approval pending.