Optical Fiber AUTO3160 - Optics and Spectroscopy Spring 2012

1. Optical Fiber AUTO3160 - Optics and Spectroscopy Spring 2012 Miguel Angel Chourio Master’s degree in Telecommunication Engineering University of Vaasa, Finland

2. INDEX • What is a Optical Fiber • Single ModeOpticalFiber • MultimodeOpticalFiber • Single mode Vs. MultimodeFiber • Snew’sLaw - Total InternalReflection • HowisglassopticalFibermade • Applications • Conclusions • References

3. Optical Fiber • Optical Fiber uses glass to guide the light impulses from source to destination. • Optical Fiber provides a very large bandwidth data rates. • Based on its requirements and needs, Networks communication are implemented as • Copper • Optical Fiber • Wireless (Signal are propagatedoverthe air)

4. Glass Fiber Structure • Thecorevaryitsdimensionseitherthefiberis single ormultimode. • TheCladdingsurrondsorcoverthecore and isdesignedtoprevent light lossfromthefiber. • Sincethe light can onlytravel in onedirectionovertheoptical cable, twofibers are requiredtosupport full duplexoperations • Light enterintothecore and itscladdingalongthefiber

5. Ray Light explanation • Typically, the core size on Multiple Fiber are large enough so that, multiple light ray can enter to the core at different angles along the fiber. • Multimode fiber employ Light Emitting Diodes (LEDs) with its proper angles to represent the transmitted data as bits along the media. • Due the light enters the fiber at different angles, it takes different amount of time to travel down the fiber, and it may become confuse at the receiver side. • This effect known as modal dispersion, limit the length of multimode fiber segments.

6. Ray Light explanation • In “Single Fiber”, thecoreis so tinythatonlyone light raywhichis perpendicular tothe cable may be propagatealong. • Single Fiberemploys a single Ray of Light as sourcegeneratortopropagatethesignals, becausethe laser isuni-directional and travelsalongthe center of thefiber.

7. Single mode vs. MultimodeFibers

8. Waveguidecalculation of FiberMode • Here is fiber mode calculation based on Waveguide Calculation by Fiber Optics for Sale Company (USA) • V number determines the numbers of guided modes. • When V numberissmallerthan 2.405 onlyonemode can be guidedbythefiber, thisiscalled single modefiber. • When V Numerislargerthan 2.405 severalsmodes can be guidedbythefiber. • As higer V number as largernumber of modes, thisiscalledMultimodeFiber

9. MultimodeFibersis more complex • Themultimodefiberkeepsthesamestructure as single modeunlikethesieze of thecoreglassisbigger. The x (axes )shows fiberraduisThe y (axes ) shows refractiveindex Thecoreusually has a refractiveindex n1 = 1.48 Thecladdinghas a refractiveindex n2 = 1.06 ThisiscalledStep-indexfiber Refractiveindexprofilein multimodefibers

10. Snew’sLaw- Total InternalReflection • Snew’sLaw describe therelationbetweentheangles of incidents and refractions. • Whenthe Light Raypassfrom a higherindex material to a lowerindex material, light refractionoccurs. • When light incidents at interface betweenthecore and thecladding has differentsanglessomepower are reflacting back and somepowerenterintothecladding Cladding • As theangleisincreaseslargerthanthe target no more light enterintotheCladdinglayer and allthe light reflect back intothecore. Thisiscalled “Total InternalReflection”. Core

11. OpticalFibermanufacturer • Generallyitconsistson 2 stepsby GlassFiberpreform FiberManufacturingProcess • 1st Step a preformismadeand it has quite exactlythesameproportioncore as thecladding material. • 2nd Stepthepreformpassthrough a monitor todeploythe final fiberinto a drum to be storage and distributed.

12. Specialfiberdrawingtower • OpticalImplementationTechnologyoffersbyYangtze Optical Fibre and Cable Company Ltd. (YOFC) a Chinese company established in May 1988. Referencehttp://en.yofc.com.cn/jjfa/&FrontComContent_list01-1293619915029ContId=279b108f-7f52-4951-a347-9afb3bec0dcb&comContentId=279b108f-7f52-4951-a347-9afb3bec0dcb&comp_stats=comp-FrontComContent_list01-1293619915029.html

13. Optical Fibers Applications • Nowadays, Optical Fibers connects the world under the sea and over the land • Basically all digital communications travels via fiber. • A single fiber can carry more communications than the biggest copper cable.

14. Optical Fibers Applications • Telecommunications | Internet | Fiber at Home • Video Streaming | Data Centers | Computer Networks • Video and Audio • Military | Governments | Airports |Hospital • Intelligent | Public transportations • Everywhere

15. Conclusion • OpticalFiber = Optical + Fiber “ At Speed of Light” • Single ModeFiberprovideshigher data ratesspeed and more distancethan Single Mode • Single Mode uses a single Ray of Light whileMultimodeFiberemployLight Emitting Diodes (LEDs) to propagate the signal. • At present, thefiberapplicationmight be infinite, howevera deepanalysis and designisrecommendedbeforeimplement a network.

16. Reference [1] Yangtze Optical Fibre and Cable Company Ltd. (YOFC) http://en.yofc.com.cn/jjfa/&FrontComContent_list01-1293619915029ContId=279b108f-7f52-4951-a347-9afb3bec0dcb&comContentId=279b108f-7f52-4951-a347-9afb3bec0dcb&comp_stats=comp-FrontComContent_list01-1293619915029.html [2] CISCO Networking Academy Program CCNA 1 and 2 book, 3rd Edition, Indianapolis – CISCO press, 2003. [3] About Optical Fiber,link: http://en.wikipedia.org/wiki/Optical_fiber [4] Eugene Hecht – Optics , International Edition, Pearson Education

17. Thankyou • Kiitos • Tack