Fiber Optic Communications TE-504 Department of TE&CE IIU Islamabd

1. Fiber Optic CommunicationsTE-504Department of TE&CE IIU Islamabd Instructor :Engr. Muhammad Ashraf Bhutta

2. Lecture 1 - outline • Course info • Fiber optic introduction • fiber basics • history • modulation formats • digital/analog modulation • ray optics description of fibers • Relevant chapters in the book:1-2.1

3. Course outline • week.1 Introduction, Optical fibers - geometrical description • week.2Optical fibers - waveguiding, Maxwells equations • week 3 Optical fibers - dispersion, pulse broadening, attenuation • week 4 Optical fibers - nonlinearities • Week 5 Solitons, nonlinear phenomena • week 6 Light emitting diodes, semiconductor lasers

4. Course outline… • week 7 Photodetectors, receivers • Week 8 Optical amplifiers • Week 9 Optical amplifiers • Week 10 Receiver performance • Week 11 System design • Week 12 Dispersion compensation • Week 13 Multi-channel systems, WDM / OTDM • Week 14 Coherent systems, Microwave Photonics • NOTE: Each week we,ll have two lectures(02hrs+01hrs)

5. Home assignment, Research papers • 4 Assignments • Three quizez • Two research Papers on the topics covered in the course • Text books • Fiber Optic Communications Technology 3rd edition By Djafar K. • Optical fiber communications Third edition by Gerd Keiser • Fiber Optic Communication systems Third Edition by Govind p. Agrawal

6. A definition of Fiber Optics • Utilization of electromagnetic waves in dielectric, circular waveguides combined with optoelectronic devices (LEDs, lasers, photodiodes, amplifiers, etc.) • Applications of fiber optics: • communication • medical applications • optical sensing • power distribution • welding, drilling...

7. Some definitions • Visible spectrum 0.4 to 0.7 micrometer • Optical (guided light) communication field 700-1600 nm • Reflection and refraction • refractive index n=c/v • Dispersion: process of separating light into each of its component frequencies.

8. Diffraction:bending of light as it passes through an openong in an obstacle • Absorption:conversion of light into heat • Amount of energy contained in light is determined by wavelength or frequency • E=hf(joules per photon) • Light passing from a lower refractive index to a higher one is bent toward the normal

9. Fresnel reflection • Independentof the index of the two media , a small portion of light will always be reflected when light passes from one index to another ,this is called fresnel reflecton(p) • P=(n-1/n+1)2 • dB=10log10(1-p)

10. The electromagnetic spectrum

11. Fiber Optic Commnication Link

12. Optical Fibers

13. A multi-disciplinary technology

14. Undersea systems

15. Fiber basics

16. Optical Fibers

17. Fiber advantages • Low attenuation (0.2 dB/km) • Large bandwidth (35 THz) • Wavelength independent attenuation in the transmission window • The enormous capacity of an installed fiber can be utilized in future as the demand increases • Small geometry and low weight • Flexible • Easy to install

18. Fiber advantages…… • Low sensitivity to moisture • The fiber endpoints handle large differences in voltage • Immune to electromagnetic interference • No crosstalk between fibers • Damage can not cause sparking • Potentially low cost • Well suited for future broadband services

19. WDM-OTDM

20. Progress in Lightwave communication (2)

21. Direct detection digital and analog systems

22. Analog and digital signals

23. The dB units

24. Fiber types

25. Ray-optics description of step-index fiber (1)

26. Numerical apereture