Cochin University of Science and Techology (CUST) 2009-1st Year M.Sc Photonics and Bio- Photonics (FIVE NTEGRATED ) VI SEMESTER IN PHOTONICS, CEL 1602 FIBRE OPTICS - Question Paper

IPHO.6/09.02
M.Sc. DEGREE (FIVE YEAR INTEGRATED COURSE) VI SEMESTER exam IN
PHOTONICS, APRIL 2009
CEL 1602 FIBRE OPTICS
Time : three Hours. Maximum marks : 50
PART — A
(Answer any 5 questions)
(Each ques. carries 2 marks)
(5 x two = 10)
I. a. discuss Goos — Haenchen shift.
Monomode fibers are preferred to multimode fibers ituilver interferometric sensors. Why?
Write down the advantages of fiber optic sensors over kind sensors.
provide notes on an optical IC for electro optic modulation
elaborate holey fibers? Mention its uses.
elaborate skew rays?
provide note on Grin-rod Lens and provide 1 of its application.
h. Mention optical transmission windows in a silica fiber. Mention their significance.
PART — B
(Each ques. carries 8 marks)
(5 x eight = 40)
II. A. elaborate modes in a wave guide. discuss the existence of mode structure
in a planar wave guide and find the expression for mode separation.
OR
B. a. discuss numerical aperture of a fiber and find its expression.
b. discuss the advantages of single mode fibers over other kinds of fibers.
a. Briefly discuss various kinds of scattering losses in an optical fiber.
b. Write down the expression for radiation losses in a band fiber. Can you
suggest an example for which band losses in the fibers can be used for device
application.
OR
discuss various kinds of intra modal dispersion mechanisms in a fiber. Also
provide the principle of dispersion flattered fiber.
A. define the fabrication of polymer optical fibers and discuss its applications.
OR
B. a. define any 1 method for the measurement of fiber refractive index profile.
b. discuss a few of the applications of Erbium doper fibers.
A. a. discuss the principle of cylindrical ferrule fiber connector.
b. Fresnel reflection at butt joint with air gap in a multimode step index fiber
is 0.46 dB. Determine the refractive index of the fiber core.
OR
B. a. discuss how a star coupler is fabricated.
'b. A 4 port multimode fiber FBT coupler has 60 Inv optical power launched into
port 1. The measured output power at the ports 2,3 and four are 0.004, 26.0 and
27.5 tw respectively. Determine the excess loss, insertion losses ranging from the input
and output port, the cross talk and split ratio of the device.
VI. A.
B.
What is sag nac effect? discuss the theory fiber gyroscope.
OR
discuss briefly any 2 of the following:
Medical applications of fiber.
WDM
(iii) Fiber loss sensor.

Earning:   Approval pending.