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G1124 Pages: 2

APJ ABDUL KALAM TECHNOLOGICAL UNIVERSITY
SEVENTH SEMESTER B.TECH DEGREE EXAMINATION(S), MAY 2019

Course Code: EC469
Course Name: OPTO ELECTRONIC DEVICES

PARTA
Answer any two full questions, each carries 15 marks.
Explain Franz-Keldysh effect in semiconductors with necessary diagrams?
Explain the types of semiconductors based on band gap structures with relevant
diagrams.
Discuss deep level transitions in semiconductor
What are QW lasers? Explain its constructional features
Discuss axial and transverse modes in laser
Explain working principle of DFB laser with the aid of suitable diagram
PART ‏تا‎
‎Answer any two full questions, each carries 15 marks.
What is the basic principle of white LED
Describe the structure and working of InGaN/GaN laser diodes
Discuss the principle of optical memory
Explain the working principle of electro-optic modulators with suitable diagrams
Explain the principle of white light LED, based on phosphor converters
What is meant by acousto-optic effect? Explain Raman-Nath modulator

PART C
Answer any two full questions, each carries 20 marks.
Explain the principle of organic LED

Draw the structure of Schottky barrier photodiode and give an application

A silicon APD has a quantum efficiency of 65% at a wavelength of
900nm.Suppose a 0.5uW of optical power produces a multiplied photocurrent of
10uA,find the multiplication factor M.

Explain the principle of attenuators

Discuss the principle of tunable optical filters

Explain the principle of operation of a 1:1 fiber optic directional coupler with a

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Duration: 3 Hours

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