Optical Fibres ELEC8350

Transcription

1 PHOTONICS AND OPTOELECTRONICS PROGRAM Optical Fibres ELEC8350 Lecturer in Charge: Prof Gang-Ding Peng Any enquiry: & U N I V E R S I T Y O F N E W S O U T H W A L E S SCHOOL OF ELECTRICAL ENGINEERING AND TELECOMMUNICATIONS C:\Users\raye\Desktop\Outlines-S2-2009\ELEC8350_s22009_Peng.doc : 1

2 Course contents Unit 1 Unit 2 Unit 3 Unit 4 Unit 5 Unit 6 Unit 7 Unit 8 Unit 9 Unit 10 Unit 11 Unit 12 Introduction to Optical Fibres Light Propagation in Step Index Multimode Optical Fibre Light Propagation in Graded Index Multimode Optical Fibre Light Propagation in Single-mode Optical Fibre Properties of Single-mode Fibres Optical Losses in Glass Losses at Fibre Connections and Bends Repeater Spacing Design Fibre-based Components Measurement of Optical Fibre I Measurement of Optical Fibre II Fibre Manufacturing and Cabling C:\Users\raye\Desktop\Outlines-S2-2009\ELEC8350_s22009_Peng.doc : 2

3 Objectives Course Overview At the conclusion of this course, you should have a good understanding of 1. The fundamental aspects of multimode and single mode optical fibres; 2. The main technical issues and considerations of using optical fibre in communication systems. Overview This course, Optical Fibres, explores what happens to light propagating in optical fibres and describes how we can measure a range of defining characteristics of fibres. We will examine how fibres are used, in both communication links and devices and discuss in detail the design and manufacture of fibres with various desirable properties. Unit 1, Introduction to Optical Fibres, introduces the development of modern optical fibres, and the applications of these fibres to various aspects of modern life. Unit 2, Light Propagation in Step Index Multimode Optical Fibre, looks at the simplest fibre type, i.e. the step index multimode optical fibre. The important concepts that we need to grasp in this unit are the numerical aperture, critical launching angle, time delay of each ray in the fibre, and the bandwidth calculation of the fibre. Unit 3, Light Propagation in Graded Index Multimode Optical Fibre, looks at how to modify the design of the fibre so that it can offer more bandwidth. The first approach is the topic of this unit. Graded index multimode fibre offers at least a hundred times the bandwidth of a step index fibre. Unit 4, Light Propagation in Single-mode Optical Fibre, investigates how we might produce a fibre that has infinite bandwidth by allowing only one ray to propagate in the fibre. Unit 5, Properties of Single-mode Fibres, continues our study of single-mode optical fibre. In this unit we will look at pulse dispersion and spot-size in single-mode optical fibre. Unit 6, Optical Losses in Glass, examines loss of power from the signal in glass fibres. After studying this unit you will know the main sources of loss from fibres. Unit 7, Losses at Fibre Connections and Bends, considers the optical losses which occur in the application of fibre in telecommunication systems. These losses occur when we connect the fibre to the transmitter and to the photodetector and when it is necessary to join several pieces of fibre to form a link. Unit 8, Repeater Spacing Design, explores the two approaches to the spacing design problem: the power-budget design and the dispersion-budget design. Unit 9, Fibre-based Components, looks at fibre connections which have little loss and how fibres can be used to change the information carried in themselves, especially where such changes are deliberate and systematic. In Unit 10, Measurement of Optical Fibre I, you will learn how to ascertain the properties of a given length of fibre, such as its attenuation at different operating wavelengths, its bandwidth, cut-off wavelength, spot-size and many other parameters. Unit 11, Measurement of Optical Fibre II, we will look at further methods used to measure the properties of fibres i.e. the use of Optical Time-Domain Reflectometer (OTDR), cut-off wavelength for single-mode operation, chromatic dispersion and the spot-size of single-mode operation at certain wavelength. C:\Users\raye\Desktop\Outlines-S2-2009\ELEC8350_s22009_Peng.doc : 3

4 Unit 12, Fibre Manufacturing and Cabling, focuses on how optical fibres are manufactured and how these fibres are cabled for installation. You will learn how low-loss fibres are made. You will also learn about different kinds of optical cables and the important components making up the cable. Assumed knowledge and skills To successfully undertake this course it will be assumed that you have knowledge and skills in introductory (digital) communication systems theory electromagnetic waves and classical optics vector calculus and complex analysis. To successfully undertake this course you need: this study guide your Information Guide for Students contact details for your Facilitator internet access so you can interact with your class and access reference material located on the internet. access to further reading resources as required Textbooks There is no prescribed textbook for this course. However, you should be considering the development of your professional library which should contain a reference text about fibres. We recommend you obtain EITHER of the following. J. Senior, (1992)Optical Fiber Communications, 2nd edn Prentice-Hall, G. Keiser, (2000)Optical Fiber Communications, 3rd edn McGraw-Hill, Both go beyond the scope of this course, and include chapters on the sources & detectors that complement fibres and optical communication systems. Both these texts will prove equally useful in this course Other useful resources Those who wish to revise the background of electromagnetism should try D. K. Cheng, (1989) Field & Wave Electromagnetics, 2nd ed (Addison-Wesley) Though dated, this is still an excellent introductory text. Basic concepts taken from communication engineering can be found in B. P. Lathi, Modern Digital & Analog Communication Systems, 3rd Edn (Oxford, 1998) This is an up-to-date textbook covering most topics in modern communication systems. Its treatment is well-balanced and descriptive. The standard background textbook on optics is Max Born and Emil Wolf Principles of Optics: Electromagnetic Theory of Propagation, Interference and Diffraction of Light Cambridge U.P., New York, 1999 [1959]. 7th edition. The following may be of assistance with the mathematics of optical waveguide theory. C:\Users\raye\Desktop\Outlines-S2-2009\ELEC8350_s22009_Peng.doc : 4

5 Snyder, A.W. & Love, J. D. (1983) Optical Waveguide Theory (Chapman & Hall, 1983) This is a comprehensive, highly mathematical reference, detailing both ray & modal analysis. Remember, in an area of engineering evolving as rapidly as technologies based optical waveguides, publishers of textbooks have great difficulty keeping up. Please, if you find a good book, let us know about it. Exercises and Tutorials You will be given several sets of tutorial questions and you are asked to work them out in this course. A tutor will be arranged to responding your questions at a set time each week. The assessment for this course will be designed to measure your achievement of the following learning outcomes: Learning outcomes When you have completed this course, you should be able to describe and analyse what happens to light propagating in optical fibres discuss in detail the design and manufacture of fibres with various desirable properties measure the defining characteristics of fibres discuss how fibres are used, in both communication links & devices. Self assessment At the end of each unit you ll find some exercises designed to help you test your understanding of what you are reading. Where appropriate, answers to the exercises are provided so you can check your answers. Do try to complete the exercises on your own first. If you have problems, discuss them with your teacher. Assignments The three assignments will be sent to you in this course. The detail requirement will be given when you receive the assignments. You are required to complete and submit your report at a given time. All the assignment materials you submit must be your own original work. In Week 1 of session you will be advised of how you will be assessed in this course. Please attach one of the coversheets provided at the end of the course overview in your study guide to the front of each of your assignments. Remember to keep a copy of your assignment in case the your work is lost or mislaid. Assessment Your final mark is determined by several parts: First assignment 10% Second assignment 10% Third assignment 9report 20% Final Examination 60% Total: 100% C:\Users\raye\Desktop\Outlines-S2-2009\ELEC8350_s22009_Peng.doc : 5