Cochin University of Science and Techology (CUST) 2010-1st Year M.Sc Photonics and Bio- Photonics (FIVE NTEGRATED ) VI SEMESTER IN PHOTONICS, Time : 3 Hours CEL 1601 OPTOELECTRONICS - Questio

IPHO.V1/10.52
M.Sc. DEGREE (FIVE YEAR INTEGRATED COURSE) VI SEMESTER exam IN
PHOTONICS, APRIL 2010
Time : three Hours
CEL 1601 OPTOELECTRONICS
(2007 Onwards) c.
\
Maximum Marks : 50
PART - A ,(Answer any 5 questions) "--- L;(All ques. carry EQUAL marks) k
e 0
z.------Ai (5 x two = 10)s'cv ..-- • (a),./Differentiate ranging from quantum wells and super lattices. '-'\ Svi (3
(b) discuss Franz-Keldysh effect e- (9 elaborate the various factors that determine the external quantum efficiency of an LED?
d) Write a note on optical heterodyning technique to measure the high speed response of tzc
.C? photodectors.
(e) How is mode-locking achieved in semiconductors? (fl Enumerate the important features for high efficiency design of GaAs/A1GaAs solar cells.
(h) A sample of GaAs has 10' (g) Briefly discuss the working. of plasma panel displays.
electrons/cm3 and five x 10 14 holes/cm3 . obtain the total conduction
current density for an applied field of 100V/cm if pe = 5000cm2/v.s and Ph = 400 cm2/v.s.
PART - B
(All ques. carry EQUAL marks)
(4x 10 = 40)
A. provide a detailed account of various processes of electron-hole pair formation and recombination in
semiconductor materials.
OR
B. Estimate the density of states in intrinsic and extrinsic semiconductors. Estimate the density of
electrons in the conduction band of intrinsic Si (6 g = 1. ieV) and diamond (e g 5.6e V) ,
room temperature.
-t
Ill. A. define the various LED structures and explain their merits and demerits.
OR ta,„
B. With necessary diagrams discuss various absorption processes in semiconductors.
A. With the help of diagrams discuss the operation and spectral characteristics of a solar cell. describe
fill factor of a solar cell. elaborate the factors that influence it?
OR
B. discuss the working of an Avalanche Photo Diode. explain the merits and demerits of the device
over a PIN photodiode.
A. discuss the principle and operation of photoluminescence, Electroluminescence, plasma panel and
LCD displays.
OR
B. discuss the principle of operation of an EO modulator. Differentiate ranging from analogue and digital
modulation schemes.

Earning:   Approval pending.