Student Supplement for Optoelectronics and Photonics: Principles and Practices Second Edition A Complete Course in Power Point.

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1 Studet Suppleet for Optoelectroics ad Photoics: Priciples ad Practices Secod Editio A Coplete Course i Power Poit Chapter [ February 04]

2 Copyright Iforatio ad Perissio: Part I This Power Poit presetatio is a copyrighted suppleetal aterial to the textbook Optoelectroics ad Photoics: Priciples & Practices, Secod Editio, S. O. Kasap, Pearso Educatio (USA), ISBN-0: , ISBN-3: Pearso Educatio. Perissio is give to istructors to use these Power Poit slides i their lectures provided that the above book has bee adopted as a priary required textbook for the course. Slides ay be used i research seiars at research eetigs, syposia ad cofereces provided that the author, book title, ad copyright iforatio are clearly displayed uder each figure. It is ulawful to use the slides for teachig if the textbook is ot a required priary book for the course. The slides caot be distributed i ay for whatsoever, especially o the iteret, without the writte perissio of Pearso Educatio. Please report typos ad errors directly to the author: safa.kasap@yahoo.co

3 PEARSON Copyright Iforatio ad Perissio: Part II This Power Poit presetatio is a copyrighted suppleetal aterial to the textbook Optoelectroics ad Photoics: Priciples & Practices, Secod Editio, S. O. Kasap, Pearso Educatio (USA), ISBN-0: , ISBN-3: Pearso Educatio. The slides caot be distributed i ay for whatsoever, electroically or i prit for, without the writte perissio of Pearso Educatio. It is ulawful to post these slides, or part of a slide or slides, o the iteret. Copyright 03, 00 by Pearso Educatio, Ic., Upper Saddle River, New Jersey, All rights reserved. Prited i the Uited States of Aerica. This publicatio is protected by Copyright ad perissio should be obtaied fro the publisher prior to ay prohibited reproductio, storage i a retrieval syste, or trasissio i ay for or by ay eas, electroic, echaical, photocopyig, recordig, or likewise. For iforatio regardig perissio(s), write to: Rights ad Perissios Departet.

4 Iportat Note You ay use color illustratios fro this Power Poit i your research-related seiars or research-related presetatios at scietific or techical eetigs, syposia or cofereces provided that you fully cite the followig referece uder each figure Fro: S.O. Kasap, Optoelectroics ad Photoics: Priciples ad Practices, Secod Editio, 03 Pearso Educatio, USA

5 Waveguide Coditio π (a) θ φ λ cos π iteger, core refractive idex, θ is the icidece agle, a is the core thickess. φ is the phase chage upo TIR at the / boudary Miiu θ ad axiu ust still satisfy TIR There are oly a fiite uber of odes Propagatio alog the guide for a ode is β k siθ π siθ λ

6 Modes i a Plaar Waveguide: Suary π (a) λ cosθ φ π Phase chage upo TIR at /, ad depeds o θ β k siθ π siθ λ E(y,z,t) E (y)cos(ωt β z) Travelig wave alog z Field patter alog y

7 Iterode (Iterodal or Modal) Dispersio Scheatic illustratio of light propagatio i a slab dielectric waveguide. Light pulse eterig the waveguide breaks up ito various odes which the propagate at differet group velocities dow the guide. At the ed of the guide, the odes cobie to costitute the output light pulse which is broader tha the iput light pulse.

8 Exaple o Waveguide Modes Cosider a plaar dielectric guide with a core thickess 0 µ,.455,.440, light wavelegth of 900. Fid the odes TIR phase chage φ for TE ode ta ( φ ) si θ cosθ / TE ode Waveguide coditio π (a) λ cosθ φ π Waveguide coditio φ ak cosθ π

9 ta ak / si θ π cosθ cosθ f ( θ ) TE ode

10 π si θ α δ λ Mode, icidece agle θ ad peetratio δ for a plaar dielectric waveguide with d a 0 µ,.455, / θ δ (µ) Fudaetal ode Critical agle θ c arcsi( / ) 8.77 Highest ode

11 Waveguide Dispersio Curve The slope of ω vs. β is the group velocity v g

12 Mode Group Velocities fro Dispersio Diagra Group velocity vs. frequecy or wavelegth behavior is ot obvious. For the first few odes, a higher ode ca travel faster tha the fudaetal. The group velocity v g vs. ω for a plaar dielectric guide with a core thickess (a) 0 µ,.455,.440. TE 0, TE ad TE 4

13 Not i the textbook A Plaar Dielectric Waveguide with May Modes.08 c / c / v g ω cutoff.05 Slower tha fudaetal (c/ )siθ c c / ω The group velocity v g vs. ω for a plaar dielectric guide Core thickess (a) 0 µ,.455,.440 [Calculatios by the author]

14 Not i the textbook Dispersio i the Plaar Dielectric Waveguide with TE 0 ad TE (Near cut-off) ω ω Iput light pulse TE TE 0 Output light pulse Broadeed pulse ω cutoff c / v gax c/ v g v gi Operatig frequecy v gax TE 0 TE TE λ πc/ω c / ω v gi c/ L L τ v g v i gax τ L c Spread i arrival ties Dispersio ω

15 Not i the textbook A Plaar Dielectric Waveguide with May Modes Operatig frequecy c / c / v g ω cutoff ω Multiode operatio i which ay odes propagate with differet group velocities v g vs. ω for a plaar dielectric guide with a core thickess (a) 0 µ,.455,.440 [Calculatios by the author] Rage of group velocities for 65 odes (c/ )siθ c c /

16 Not i the textbook Dispersio i the Plaar Dielectric Waveguide with May Modes Far fro Cutoff c / Operatig frequecy c/ θ c θ c (c/ )siθ c c/ c / TE highest v g ω Rage of group velocities for 65 odes (c/ )siθ c v g i c si θ c c v g ax c τ L v g i v g ax τ L c c τ L c ( ) ( ) c c (Sice ad are oly slightly differet.)

17 Not i the textbook ω Dispersio i the Plaar Dielectric Waveguide May Modes τ Very short iput pulse θ c θ c TE 0 Output pulse ω Broadeed pulse TE highest τ L v g i v g ax τ L ( c ) τ L c (Sice / )

18 Updates ad Corrected Slides Class Deostratios Class Probles Check author s website Eail errors ad correctios to safa.kasap@yahoo.co