Electronics and Communication Engineering > Optical Communications (ETEC 403)

Optical Communications (ETEC 403)

Instructor(s): Prof. Parul Dawar
Prof. Parul Dawar

Title: Professor

Company: Guru Teg Bahadur Institute of Technology

Website: http://www.gtbit.org/

Parul Dawar is Assistant Professor of Electronics and Communication in Guru Tegh Bahadur Institute of Technology since July 2007. She is currently pursuing her PhD from DTU (formerly D.C.E) under the guidance of Prof. Asok De.


She is the author of two books on Electromagnetic Field Theory and has published extensively in International journals.
 
 



Course Description:

This Course is for B.Tech final year students of GGSIPU and requires pre-requisite knowledge of applied physics,electronic devices and components.

Credits Earned: Lectures--> 3, Practical--> 1 Total -> 4

Reference  Books for the Course:

Gerd Keiser Optical Fiber communications 3rd ed, Mc Graw-Hill
Optical Fiber Communications, 3/E. Author,  Senior  John M. Publisher, Pearson Education, 2009.

This course will cover:the following topics:

1. Introduction to Optical Fiber and Optical Communications: what, history, pros, cons

2. Ray Theory and Transmission
Nature of light, ray optics, refractive indices, snell's law, total internal reflection, acceptance angle, numerical aperture, optical fiber structres

3. Electromagnetics
Maxwell equations and electromagnetic wave propagation, Plane Waves
Phase velocity, Polarization, Maxwell equations, Wave equations, Solutions of wave equations,Poynting vector
Fresnel reflection, Total internal reflection, Evanescent wave

4. Mode Theory for Waveguides
• Plane wave representation in planar waveguides
• Transverse resonance condition
• The wave equation and general solutions
• Eigen value equations for symmetric slab waveguides
• Weakly guiding waveguide example
• Cutoff condition and number of modes
• Remark on asymmetric waveguides for integrated photonics

5. Waveguiding in optical fibers
• Meridional / skew rays and their vectorial characteristics
• Concept of linearly polarized modes
• Cutoff condition / wavelength
• Selected key concepts on singlemode fibers

* Advanced materials

• Field analy sis of the weakly guiding fiber
• Solving the wave equation*
• Eigenvalue equation for linearly polarized modes

6. Transmission Characteristics of Optical Fibers
• Fiber attenuation
• Fiber dispersion
• Group velocity
• Material dispersion
• Waveguide dispersion
• Chromatic dispersion compensation
• Polarization mode dispersion
• Polarization-maintaining fibers

7. Absorption and Material Dispersion
• Complex refractive index
• Material dispersion
• Classical theory - Lorentz oscillator model
• Signal velocity in a dispersive medium
 
8. Optical Sources: Laser, LED

9. Data Communication Networks
• Plastic optical fiber link
• Advanced Multiplexing Strategies- Optical TDM,
• Optical Transport Network

10. Data Communication Networks: Topologies & Protocols

11. Applications: Industrial, Optical sensor, Consumer

12. Optical fiber communication system: History, Evolution, Telemetry

Course Sessions:
  • Overview of the Course
  • Content Author(s): Prof Parul Dawar

    Session Description:

    Provides an Introduction and Overview of Photonics and Optical Communications.


    • Motivations for Lightwave Communications
    • Advantages of Optical Fiber Communications
    • Optical Spectral Bands
    • Decibel Units
    • Network Information Rates
    • Wavelength-Division Multiplexing (WDM) Concepts
    • Standards for Optical Fiber Communications
    • Historical Development


  • Introduction to Fiber Optics
  • Content Author(s): FOA

    Session Description:

    Introduction to Fiber Optics: part of FOA Series on fiber optics. This lecture covers optical fiber, how it works, the types of fiber, fiber specifications, and how it is made.


  • Lecture 1 Introduction to Optical Fiber Communications
  • Content Author(s): Prof Parul Dawar

    Session Description:

    Optical Fiber and Optical Communications:

    what, history, pros, cons


  • 1.1 Manufacturing of fiber
  • Content Author(s): Moe Sal

    Session Description:

    How it is made: Fiber Optics. The session takes the students through the entire process of manufacturing fiber for use iin telecommunications and other industries.


  • 1.2 Total Internal Reflection
  • Content Author(s): FOA

    Session Description:

    In this lecture by FOA,  "refraction" and "total internal reflection," the optical terms for how light is bent or reflected at the boundary of two different materials are described.

    Total internal reflection is important in fiber optics as it is the reason that light can be trapped in the core of the fiber, making optical fiber transmission possible. Using a visible red laser from a VFL, total internal reflection in a large core plastic fiber is demonstrated.


  • 1.3 Copper fiber or wireless
  • Content Author(s): FOA

    Session Description:

    One of the most common questions is:

    should my communications system use fiber or copper - or wireless?

    Fiber has been the clear winner in long distance communications since the mid 1980s for simple economics - nothing transmits large amounts of data over longer distances cheaper than fiber. For a long time, fiber and copper battled for the LAN desktop, but while they focused on each other, wireless took over the connection to user devices. But we still have all three communications media, so which one is the best choice?


  • Lecture 2: Ray Theory and Transmission
  • Content Author(s): Prof Parul Dawar

    Session Description:

    Nature of light, ray optics, refractive indices, snell's law, total internal reflection
    acceptance angle, numerical aperture, optical fiber structres


  • 2.1 Difference in step index and graded index
  • Content Author(s): vedupro

    Session Description:

    In Step-Index Optical Fiber, the diameter of the core is high therefore more number of modes of propagation of light can be possible. So the fiber is also called as multi mode step-index fiber cladding (110 μm) and core (10 μm).

    GRADED-INDEX OPTICAL FIBER

    If the core has a non-uniform refractive index that gradually decreases from the center towards the core-cladding interface, the fiber is called a Graded-Index Fiber.Graded Index Optical Fiber has Core (50 μm) and cladding (70 μm) diameter.


  • 2.2 Cutoff wavelength of single mode fiber
  • Content Author(s): Colin Yao

    Session Description:

    The number of guided modes of  an optical fiber depends on the optical wavelength: the shorter the wavelength, the more modes can be guided. Above the cutoff wavelength, only one mode, the fundamental LP01 mode propagates.Below this wavelength, higher order modes, such as the LP11 mode will propagate: the fiber becomes a multimode fiber.

    The cutoff wavelength is an important parameter for single mode fibers because it determines the wavelength range of its operation as a single mode fiber.


  • 2.3 Multimode optical fiber
  • Content Author(s): Colin Yao

    Session Description:

    Introduces:

    optical fiber light guiding principles

    total internal reflection

    step-index multimode fiber

    modes in step-index fiber

    graded-index multimode fiber

    common fiber products on the market


  • Lecture 3: Electromagnetics
  • Content Author(s): Prof Parul Dawar

    Session Description:

    Maxwell equations and electromagnetic wave propagation
    Plane waves, Phase velocity, Polarization, Maxwell equations, Wave equations, Solutions of wave equations,Poynting vector
    Fresnel reflection, Total internal reflection, Evanescent wave


  • 3.1 Electromagnetics
  • Content Author(s): WindTechTv

    Session Description:

    Gives basic information about fiber optic cable used in wind turbines. Produced by Highland Community College for WindTechTV.


  • Lecture 4: Mode theory for waveguides
  • Content Author(s): Prof Parul Dawar

    Session Description:

    Electromagnetic theory for optical waveguiding
    • Plane wave representation in planar waveguides
    • Transverse resonance condition
    • The wave equation and general solutions
    • Eigen value equations for symmetric slab waveguides
    • Weakly guiding waveguide example
    • Cutoff condition and number of modes
    • Remark on asymmetric waveguides for integrated photonics


  • 4.1 Important equations
  • Content Author(s): GateStudy

    Session Description:

    The session discusses Waveguides and the equations that govern propagation of waves in them.


  • Lecture 5: Waveguiding in optical fibers
  • Content Author(s): Prof Parul Dawar

    Session Description:

    Waveguiding in optical fibers
    • Meridional / skew rays and their vectorial characteristics
    • Concept of linearly polarized modes
    • Cutoff condition / wavelength
    • Selected key concepts on singlemode fibers
    Advanced materials
    • Field analysis of the weakly guiding fiber
    • Solving the wave equation
    • Eigenvalue equation for linearly polarized modes


  • 5.1 Waveguiding of light
  • Content Author(s): Shaoul Ezekiel

    Session Description:

    Propoagation of light in optical fiver is discussed in great details in a MIT OpenCourseware: Fundamentals of Fiber Optics.


  • 5.2 Mode equations
  • Content Author(s): 69erthx1138¬∑

    Session Description:

    The derivation of the modal eigenvalue equation for an optical fiber. This is a key equation used in optical fiber design to calculate the number of modes supported by the fiber.


  • Lecture 6: Attenuation and dispersion
  • Content Author(s): Prof Parul Dawar

    Session Description:

    Transmission Characteristics of Optical Fibers
    • Fiber attenuation
    • Fiber dispersion
    • Group velocity
    • Material dispersion
    • Waveguide dispersion
    • Chromatic dispersion compensation
    • Polarization mode dispersion
    • Polarization-maintaining fibers
     


  • 6.1 Material dispersion
  • Content Author(s): vedupro

    Session Description:

    Material Dispersion takes place due to different speeds of different wavelength in material medium. The long wavelengths travel faster than shorter wavelengths. As a result of this the narrow pulse of light broadens thus the material dispersion occurs due to spectral width of the light source (i.e. the light source has a spread of many wavelengths).


  • 6.2 Dispersion
  • Content Author(s): vedupro

    Session Description:

    Dispersion can be defined as "the distortion or spreading of light pluses as it travels from one end of the fiber to the other end of the fiber.
    In fiber optics the information to be transmitted trough fiber is first coded in the forms of pulses which are transmitted by the fiber and finally received at output end and then decoded. The light pulses entering at different angles at input take different time to reach to output end. So the pulses are broadening at output end. If the boarding is large then it is difficult to decode the information. The deformation in the pulse is called pulse dispersion.


  • 6.3 Chromatic dispersion
  • Content Author(s): Colin Yao

    Session Description:

    Chromatic Dispersion.What effect does chromatic dispersion have on fiber optic communication systems? What is materials dispersion? What is waveguide dispersion.


  • 6.4 Explanation on dispersion
  • Content Author(s): ExploreGate

    Session Description:

    Yet another short video that explains optical dispersion in sixty seconds..


  • Lecture 7: Absorption and dispersion
  • Content Author(s): Prof Parul Dawar

    Session Description:

    Absorption and Material Dispersion
    • Complex refractive index
    • Material dispersion
    • Classical t heory - Lorentz oscillator model
    • Signal velocity in a dispersive medium
     


  • 7.1 Fiber Characterization
  • Content Author(s): FOA

    Session Description:

    As networks get faster and use more wavelength division multiplexing, long distance links may require testing for the special needs of these systems.

    Three factors are considered most important -- spectral attenuation which confirms the fiber attenuation coefficient is appropriate over the wavelengths used by WDM systems, chromatic and polarization mode dispersion which may affect the transmission of high speed systems.


  • 7.2 Types Of Attenuation in Optical Fiber
  • Content Author(s): vedupro

    Session Description:

    The power of an Optical Input decreases exponentially with increases in the distance travelled into fiber. The attenuation is defined the reduction in amplitude and intensity of a signal as it is guided through optical fiber.


  • 7.3 Absorption and Scattering Loss in Optical Fiber
  • Content Author(s): vedupro

    Session Description:

    FIBER LOSS

    ABSORPTION:
    • Hydogen impurity leads to OH bonds whose first overtone absorption causes a loss peak near 1400 nm.
    • Transition Metal Impurities lead to broad absorption in various place due to d-d electronic excitations or color center creation (Ionization)
    • For Organic Materials, C-H overtone and combination bands cause Absorptive Loss.

    SCATTERING LOSS: FROM INDEX DISCONTINUITY
    • Scatters are much smaller than the wavelength: Rayleigh and Raman Scattering
    • Scatters are much bigger than the wavelength: Geometric Ray Optics
    • Scatters are about the same size as the wavelength: Mie Scattering
    • Scatters are sound waves: Brillouin Scattering


  • 7.4 Absorption - EXFO animated glossary of Fiber Optics
  • Content Author(s): EXFO Tube

    Session Description:

    The transformation of light into heat as it passes through a dense medium.

    EXFO's Be-an-Expert Program has produced the animated glossary of fiber optic terms. Including concise definitions and animated sequences,


  • Lecture 8 Optical Sources: Laser
  • Content Author(s): Prof Parul Dawar

    Session Description:

    Main function

    Types

    The requirements

    Basic Concepts of Laser

    Semiconductors

    Junctions

    Semiconductor Injection Laser

    Injection Laser Diode (ILD): power and efficiency, structures and characterisics


  • Lecture 8 cond: Optical Sources: LED
  • Content Author(s): Prof Parul Dawar

    Session Description:

    LED:

    Pros and cons

    Power and efficiency

    Structures and characterisics


  • 8.1 Laser
  • Content Author(s): Prof Shaoul Ezekiel

    Session Description:

    Part of MIT OpenCourseware: Understanding Lasers and Fiberoptics. This session describes in depth the Lasers, their type, how they work and their properties.


  • 8.2 Terminology
  • Content Author(s): Prof Parul Pawar

    Session Description:

    Explanation of Terms and technical words used in the Course


  • Lecture 9: Data Communication Networks
  • Content Author(s): Jeff Hecht

    Session Description:

    The session covers:

    1. Communications and fiber systems

    2: Global networks and standards

    3. Global, regional & metro telecommunications

    4 Access and local telecommunications

    5  Enabling fiber-optic technologies


  • 9.1 Plastic Optical Fiber
  • Content Author(s): FOA

    Session Description:

    Plastic optical fiber is a low cost alternative for glass fibers for short lengths and lower speeds. This video looks at the differences between POF and glass fibers and how POF is used in typical applications.


  • 9.2 Advanced Multiplexing
  • Content Author(s): Noessllc

    Session Description:

    introduction to the evolutionary processes of multiplexing, ending with WDM on fiber optic telecom systems.

    Optical TDM, Sub carrier Multiplexing, WDM Network Architecutres are covered


  • 9.3 Optical Transport Network SONET/SDH
  • Content Author(s): Xavier N. Fernando, Ryerson University.

    Session Description:

    SONET is the basic physical layer standard.

    • Other data types such as ATM and IP can be transmitted over SONET
    • OC-1 consists of 810 bytes over 125 us; OCn consists of 810n bytes over 125 us
    • Linear multiplexing and de-multiplexing is possible with Add-Drop-Multiplexers

    This presentation is part of EE 8114 course given by Xavier N. Fernando at Ryerson University.


  • 9.4 Optical Transport Network,- Access and Premises
  • Content Author(s): FOA

    Session Description:

    This lecture from FOA introduces the process of designing a fiber optic network and talks about what is involved in designing a fiber optic network.


  • Lecture 10 Data Communication Networks: Topologies & Protocols
  • Content Author(s): ITEC 1010 York U

    Session Description:

    This Session provides overview of Optic Analog Communication System Topologies & Protocols. It is a part of the Course ITEC 1010 at York U


  • 10.1 Network Topologies
  • Content Author(s): Jays Patel

    Session Description:

    In this Video Session, Jays Patel describes Network Topologies: Bus, Star, Ring

     


  • 11. Applications: Industrial, Optical Sensor, Consumer
  • Content Author(s): GAURAV PURI SUNY AT BUFFALO

    Session Description:

    In this Session, GAURAV PURI of ELECTRICAL ENGINEERING, SUNY AT BUFFALO discusses:

    principles of optical sensors and some interesting applications.

    Industrial and Consumer applications: to be added


  • 12.1 Optical Fiber Communication System: History
  • Content Author(s): Prof. R.K. Shevgaonkar, IIT Bombay. , Joan M. Gene Bernaus

    Session Description:

    In the Video lecture and the associated handout, Prof. R.K. Shevgaonkar, IIT Bombay.and Joan M. Gene Bernaus respectively present historical perspective of Optical Communications.


  • 12.2 Optical Fiber Communication System: Evolution
  • Content Author(s): Wongpaibool, Virach Virginia Tech University

    Session Description:

    In this Handout, Wongpaibool, Virach from Virginia Tech University discusses the evolution of Optical Fiber Communication Systems.


  • 12.3 Optical Fiber Communication System: Telemetry
  • Content Author(s): Allison Chaney, graduate student, Princeton

    Session Description:

    This Session is about Telemetry: a technology that allows remote measurement and reporting of information.

    .
     


  • Optical Fiber Communication: Glossary and Overview
  • Content Author(s): Nick Massa Springfield Technical Community College

    Session Description:

    In the document, Nick Massa of Springfield Technical Community College presents an overview of Fiber Optic Telecommunications.


  • Optical Communications: FAQ and Test 1
  • Content Author(s): Prof Parul Dawar

    Session Description:

    The purpose of the FAQ document in this Session is to summarize the basic concepts covered in this Course.

    Test 1 is a series of multiple choice questions. designed to assess your understanding of the material presented.


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