Keiser - Optical Fiber Communication 4thFull description
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The notes gives a comprehensive approach to fundamentals of optical fibers and their propagation characteristics,a simplified approach.
Optical Communication
optical communication
Technical publication free pdf of optical comm by v s bagadFull description
Technical publication free pdf of optical comm by v s bagad
Optical Fiber Communication
10EC72
Assignment Questions UNIT 1 Overview of Optical Fiber Communication 1. Discuss the advantages and disadvantages of optical fiber communication.
2. Explain the structure of single mode and multimode fibers and also graded index mode fibers. 3. Write a short note on fiber materials. 4.
Write a short note on optical cables.
5. What is numerical aperture? Deduce an expression for NA in step index fiber. 6.
A multimode step index fiber with a core diameter of 80µm and a refractive index difference of 1.5% is operating at a wavelength of 0.85µm. If the core refractive index is 1.48, estimate the normalized frequency for the fiber and the number of guided modes.
7. A light travelling in air strikes a glass plate at an angle θ=33deg where θ1 is measured between the incoming ray and the glass surface. Upon striking the glass, part of light beam is reflected and part is refracted. If the refracted and reflected beams make an angle of 90 deg with each other. What is the refractive index of the glass? What is the critical angle for the glass?
8.
A silica tube with inside and outside diameter of 6mm and 8mm respectively, is to have a certain thickness of glass deposited on the inner surface. What should the thickness of this glass deposition be if a fiber having a core diameter of 50µm and an outer cladding diameter of 125µm is to be drawn from this perform?
Dept of ECE, SJBIT
Page 1
Optical Fiber Communication
10EC72
UNIT 2 Transmission characteristics of Optical Fiber 1. Explain attenuation and bending losses in optical fibers. 2. Briefly explain absorption losses in optical fibers. 3. Explain material and waveguide dispersion.
4. The input power to an optical fiber is 2mw while the power measured at the output end is 2µw. If the fiber attenuation is 0.5dB/km, calculate the length of the fiber.
5. With a ray theory derive an expression for pulse delay distortion in a step index multimode fiber. 6. Discuss the fiber drawing techniques.
UNIT 3 Optical sources and detectors 1. Draw the diagram of a typical GaAlAs double hetero structure light emitter along with energy band diagram and refractive index profile and explain. 2. With a neat diagram explain edge emitting LED and surface emitting LED. 3. The Radiative and non Radiative recombination lifetimes of minority carriers in the active region of a double hetero junction LED are 60nsec and 90nsec respectively. Determine the total carrier recombination life time and optical power generated internally if the peak emission wavelength is 870nm and the drive current is 40mA. 4. Give comparison between LED and laser diode considering different parameters. 5. Explain avalanche photo diode. Dept of ECE, SJBIT
Page 2
Optical Fiber Communication
10EC72
6. Sketch and explain fabry perot resonator cavity of laser. 7. Discuss the different types of noise occur in laser diodes.
UNIT 4 Fiber couplers and connectors 1. Explain different lensing schemes used to improve coupling efficiency. 2. Explain design requirements of a good optical connector. 3. What is splicing? Explain fusion splicing method in detail. 4. An optical source has refractive index of 3.6 and is coupled to a fiber of 1.48 refractive index. Consider the medium between fiber and source has similar index as that of fiber. Calculate Fresnel reflection and loss of power in dB. 5. Describe different types of misalignments between the two joined fibers.
UNIT 5 Optical Receiver 1. With a neat diagram, explain the operation of transimpedance preamplifier equivalent circuit. 2. Explain the analog receiver briefly. 3. Discuss the possible sources of noise in optical receiver. 4. Discuss the different types of preamplifiers in optical receivers. 5. Draw the optical path through a digital link with relevant components and optical/electrical waveforms at every stage
Dept of ECE, SJBIT
Page 3
Optical Fiber Communication
10EC72
UNIT 6 Analog and digital links 1. With a diagram, explain the operation of multichannel AM briefly. 2. Explain the radio over fiber concept of a broadband wireless access network for interconnecting antenna base stations with the central controlling office. 3. Draw the optical power loss model diagram for a point to point link and explain the concept of link power budget. 4. Explain briefly NRZ codes and RZ codes used in line coding. 5. Derive the expression for rise time budget in terms of transmitter, fiber and receiver rise time. 6. What is sub carrier multiplexing? Explain.
UNIT 7 WDM Concepts and Components 1. Explain the implementation of a typical WDM network containing various types of optical amplifiers. 2. Explain the operation of polarization independent isolator made of 3 miniature optical components. 3. Explain the operation of optical adding and dropping wavelengths with 4X4 OADM devices that uses miniature switching mirrors. 4. Explain Erbium doped fiber amplifiers briefly. 5. Write a short note on dielectric thin film filters and also discuss its application. 6. Explain 4x4 and 8x8 star couplers.
Dept of ECE, SJBIT
Page 4
Optical Fiber Communication
10EC72
UNIT 8 Optical amplifiers and networks 1. Describe SONET/SDH networks and also SONET/SDH rings. 2. Write a short note on optical LAN. 3. with a frame structure of SONET/SDH. How do you get a basic data rate of 155.54Mbps for STM-1. 4. What is PDH? Explain in detail.
