M.Sc. (Semester II) (CBCS) Examination Mar/Apr-2018
Electronics
OPTO ELECTRONICS
Time: 2½ Hours
Max. Marks: 70
Instructions: Q. 1 and 2 are compulsory. Answer any three questions from Q.3 to Q.7. Answer any 5 questions. Figures to the right indicate full marks.
Q.1
Choose the alternatives given below.
08
Critical angle θC
N2/N1
sin-1 N2/N1)

N1/N2
In fibers the refractive index of the core is maximum at the centre.
Single mode step index
Multimode step index
Graded index
both a and b
In surface emitters, the emission pattern is
Isotropic
Anisotropic
Isolateral
none of these
In Helium-Neon laser the light is produced by atomic transition within atom.
Neon
Helium
Helium and Neon
none of these
shifts the polarization direction of linearly polarized light.
Quarter wave plate
Half wave plate
Retarder
None of these
is magneto optic phenomena.
Faraday's effect
Pockel's effect
Malus's law
None of these
material exhibits linear electro-optic effect.
Crystalline silica
Non-centro symmetric
Both a b
none of these
Acceptance angle for optical fiber having core index 1.48 and cladding index 1.39 is
45.440
49.600
33.900
1200
State True or false.
06
Optical fibers are good electron conductors.
Second order electro optic effect is called Pockel's effect.
In incoherent source of light optical cavity is absent.
In silica fiber 1400nm is a high loss region.
Positive uniaxial crystal is used to construct the wave plats.
Splicing means permanent fiber joints.
Page 2 of 2
SLR-UJ-328
Q.2
Attempt any two of the following.
10
Write a note on Edge emitting LED.
With suitable ray diagram, explain working principle of optical fiber.
Write a note on Photo transistor.
With suitable diagram, explain the concept of population inversion.
04
Q.3
What is optical fiber communication? Explain the types of optical fiber in detail.
08
Write a note on photodiode.
06
Q.4
Explain the principle of photo detection and give the construction and working of Avalanche photodiode.
08
Derive expression for Numerical Aperture.
06
Q.5
What do you mean by light intensity modulation? Describe in detail phenomenon of Birefringence.
08
Write a note on Faraday's effect.
06
Q.6
With necessary diagram, explain splicing technique in brief.
08
Write a note on any two types of fiber measurement.
06
Q.7
What do you mean by Acoustic Optic Modulator?
08
Write a note on Quarter wave plate.
06