Optical Fiber Communication_A. Selvarajan, S. Kar and T Srinivas

Scilab Textbook Companion for Optical Fiber Communication by A. Selvarajan, S. Kar and T Srinivas1 Created by Lochan Jolly Optical communication Electrical Engineering Tcet College Teacher None Cross-Checked by Reshma June 7, 2016

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Funded by a grant from the National Mission on Education through ICT, http://spoken-tutorial.org/NMEICT-Intro. This Textbook Companion and Scilab codes written in it can be downloaded from the ”Textbook Companion Project” section at the website http://scilab.in

Book Description Title: Optical Fiber Communication Author: A. Selvarajan, S. Kar and T Srinivas Publisher: McGraw-Hill, New Delhi Edition: 1 Year: 2002 ISBN: 0070445567

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Scilab numbering policy used in this document and the relation to the above book. Exa Example (Solved example) Eqn Equation (Particular equation of the above book) AP Appendix to Example(Scilab Code that is an Appednix to a particular

Example of the above book) For example, Exa 3.51 means solved example 3.51 of this book. Sec 2.3 means a scilab code whose theory is explained in Section 2.3 of the book.

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Contents List of Scilab Codes

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2 Light propagation in optical fiber

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3 Fiber optic technology

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4 Optical sources and transmitter circuits

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5 Optical Detectors and Receivers

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6 Integrated Optics and Photonic Circuits

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7 Wavelength Division Multiplexing

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8 Coherent Optical Communication

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9 Optical Amplifiers

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10 Photonic Switching

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11 Fiber Optic Communication System Design

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13 Video Transmission

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14 Data Communication and LAN

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16 Soliton Communication Systems

82

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List of Scilab Codes Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa

2.1 2.2 2.3 2.4 2.6 2.8 2.9 2.10 3.1 3.2 4.1 4.2 4.3 4.4 5.1 5.2 5.3 5.4 5.5 6.1 6.2 6.3 6.4 6.5 6.6 7.1 8.1 9.1

1. . 2. . 3. . 4. . 6. . 8. . 9. . 10 . 1. . 2. . 1. . 2. . 3. . 4. . 1. . 2. . 3. . 4. . 5. . 1. . 2. . 3. . 4. . 5. . 6. . 1. . 1. . 1. .

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6 7 9 13 13 15 18 19 22 22 26 28 30 32 35 37 38 40 41 44 47 47 50 50 52 54 57 60

Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa Exa

9.2 9.3 10.1 10.2 11.1 11.2 13.1 14.1 16.1 16.2 16.3 16.4 16.5

2 3 1 2 1 2 1 1 1 2 3 4 5

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62 63 66 66 70 72 76 79 82 84 85 86 88

List of Figures 2.1 2.2 2.3 2.4 2.5 2.6 2.7 2.8

1 . 2 . 3 . 4 . 6 . 8 . 9 . 10

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8 10 11 12 14 16 17 19

3.1 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.2 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

23 25

4.1 4.2 4.3 4.4

1 2 3 4

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27 29 31 33

5.1 5.2 5.3 5.4 5.5

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36 37 39 40 42

6.1 6.2 6.3 6.4 6.5 6.6

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45 46 48 49 51 53

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7.1 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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8.1 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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9.1 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9.2 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9.3 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

61 62 64

10.1 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.2 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

67 68

11.1 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11.2 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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13.1 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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14.1 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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16.1 16.2 16.3 16.4 16.5

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Chapter 2 Light propagation in optical fiber

Scilab code Exa 2.1 1

1 2 3 4 5 6 7 8 9 10 11 12 13

/ / O p t i c a l F i b e r c om mu ni ca ti on by A s e l v a r a j a n / / e xa mp le 2 . 1 //OS=Windows XP sp 3 // S c i l a b v e r s i o n 5 . 5 . 1 clc ; c l e ar a ll ;

// cas e −1 ncore=1.46 // r e f r a c t i v e i nd ex o f c o r e nclad=1 // r e f r a c t i v e i nd ex o f c l a d di n g c=3e5 // v e l o c i t y o f l i g h t i n Km/ s L =1 // l e ng t h o f p a t h i n Km NA = sqrt (ncore^2-nclad^2) // N u m er ic al a p e r t u r e delt_tau_by_L=(NA^2)/(2*c*ncore) / / m u l t i p a t h p u l s e

b r o a d e n i n g i n s /Km 14 delt_tau=delt_tau_by_L*L // b a nd wi dt h d i s t a n c e p r od u ct

Hz 15 BL=(1/delt_tau)*L // b a nd wi dt h d i s t a n c e p r od u ct Hz 16 mprintf ( ’ N u m e r i c a l a p e r t u r e =%f ’ ,NA); / / The a n s w e r s

v a r y due t o ro un d o f f e r r o r 8

17 mprintf ( ’ \ n M u l t i p a t h p u l s e b r o a d e n i n g =% fn s /Km ’ , delt_tau_by_L*1e9); / /The a ns we r p r o v id e d i n t h e

18

19 20 21 22 23 24 25 26

27

t ex tb o o k i s wrong // m u l t i p l i c a t i o n by 1 e 9 t o c o n v e r t s /Km t o n s /Km mprintf ( ’ \ n B a nd w id t h d i s t a n c e p r o d u c t =%fMHz ’ ,BL*1e -6); // The a ns we r p r ov i de d i n t he t ex t bo o k i s wrong / / m u l t i p l i c a t i o n by 1 e−6 t o c o nv e r t Hz t o MHz // cas e −2 ncore=1.465 // r e f r a c t i v e i nd ex o f c o r e nclad=1.45 // r e f r a c t i v e i nd ex o f c l a d di n g NA = sqrt (ncore^2-nclad^2) // N u m er ic al a p e r t u r e delt_tau_by_L=(NA^2)/(2*c*ncore) / / m u l t i p a t h p u l s e b r o ad e n in g i n s /m BL=(1/delt_tau_by_L)*L // b a nd wi dt h d i s t a n c e p r od u ct Hz mprintf ( ’ \n\ n N u m e r i c a l a p e r t u r e =%f ’ ,NA); mprintf ( ’ \ n M u l t i p a t h p u l s e b r o a d e n i n g =% fn s /Km ’ , delt_tau_by_L*1e9); / /The a ns we r p r o v id e d i n t h e t ex tb o ok i s wrong // m u l t i p l i c a t i o n by 1 e 9 t o c o n v e r t s /Km t o n s /Km mprintf ( ’ \ n B a nd w id t h d i s t a n c e p r o d u c t =%fGHz ’ ,BL*1e -9); // The a ns we r p r ov i de d i n t he t ex t bo o k i s wrong / / m u l t i p l i c a t i o n by 1 e−6 t o c o nv e r t Hz t o GHz


1 2 3 4 5

/ / O p t i c a l F i b e r c om mu ni ca ti on by A s e l v a r a j a n / / e xa mp le 2 . 2 //OS=Windows XP sp 3 // S c i l a b v e r s i o n 5 . 5 . 1 clc ;

9

Figure 2.1: 1

10

6 7 8 9 10

c l e ar a ll ; lamda1=0.7 / / w a v e l e n g t h i n um lamda2=1.3 / / w a v e l e n g t h i n um lamda3=2 / / w a v e l e n g t h i n um f_lambda1=(303.33*( lamda1^-1) -233.33) // e q u a t io n f o r

lambda1 11

f_lambda2=(303.33*( lamda2^-1) -233.33) // e q u a t io n f o r

lambda2 12

f_lambda3=(303.33*( lamda3^-1) -233.33) // e q u a t io n f o r

lambda3 13 mprintf ( ” M a t e r i a l d i s p e r s i o n a t Lambda 0 . 7 um=%f ” , f_lambda1) 14 mprintf ( ” \ n M a t e r i a l d i s p e r s i o n a t L ambda 1 . 3 um=%f ” , f_lambda2) // The a n sw er s v ar y du e t o r ou nd o f f

error 15 mprintf ( ” \ n M a t e r i a l d i s p e r s i o n a t Lambda 2um=%f ” , f_lambda3) // The a n sw er s v ar y du e t o r ou nd o f f

error 16 mprintf ( ’ \ n I t s

i s a s ta nd ar d s i l i c a

fibe r ’)


1 2 3 4 5 6 7 8 9


// giv en ncore=1.505 // r e f r a c t i v e nclad=1.502 // r e f r a c t i v e

i nd ex o f c o r e i nd ex o f c l a d d i n g 11

Figure 2.2: 2

12

Figure 2.3: 3

13

Figure 2.4: 4 10 11 12 13 14

V=2.4 // v n o . f o r s i n g l e mode lambda=1300e-9 // o p e r a t i n g w a ve l en g th i n m

//to find NA = sqrt (ncore^2-nclad^2) / / n u m e r i c a l a p e r t u r e a=V*(lambda)/(2*%pi*NA) // d im en si on o f f i b e r c o re i n

m 15 / / d i s p l a y 16 mprintf ( ” The n u m a r i c a l a p e r t u r e =%f ” ,NA); 17 mprintf ( ” \n D im en si on o f f i b e r c o r e =%f um” ,a*1e6) // m u l t i p l i c a t i o n by 1 e6 t o c on v e rt u n i t fro m m to um

14


1 2 3 4 5 6 7 8 9 10 11 12


// giv en V =2 // v n o . f o r s i n g l e mode a =4 // r a d i u s o f f i b e r i n um

//to find w=a*(0.65+1.619*V^(-3/2)+2.87*V^-6) // e f f e c t i v e mode

r a d i u s i n um 13 / / d i s p l a y 14 15 mprintf ( ” E f f e c t i v e mode r a d i u s =%f um” ,w)


1 2 3 4 5 6 7 8 9 10 11 12


// giv en m =0 / / f o r d om in an t mode v =0 / / f o r d om in an t mode n1=1.5 // r e f r a c t i v e i nd e x o f c o r e delta=0.01 // c or e c la d i nd e x d i f f e r e n c e a =5 // f i b e r r a d i u s i n um 15

Figure 2.5: 6

16

13 14 15 16

lambda=1.3 / / w a ve l en g th o f o p e r a t i o n

i n um

// to f in d k0=(2*%pi/lambda) / / c o n s t a n t i n /m beta= sqrt ((k0^2)*(n1^2) -(2*k0*n1* sqrt (2*delta)/a)) //

p r o p a g a ti o n c o n s t a n t i n r ad /um 17 mprintf ( ’ P r o p a g a t i o n c o n s t a n t =%f r a d /um ’ ,beta) //The a ns we rs v ar y due t o ro un d o f f e r r o r


1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17


// giv en

M=1000; / / mo de s s u p p o r t e d lambda=1.3; / / o p e r a t i n g w a ve l en g th i n um n1=1.5; // r e f r a c t i v e i nd ex o f c o r e n2=1.48; // r e f r a c t i v e i nd ex o f c l a d di n g

//to find V= sqrt (2*M) // n o r ma l i se d f r e qu e n cy V no . NA = sqrt (n1^2-n2^2) / / n u m e r i c a l a p p e r t u r e R=lambda*V/(2*%pi*NA) // r a d i u s o f f i b e r i n um

// dis pla y mprintf ( ” Core Rad ius=%fum” ,R) / / The a n s we r p r o v i d e d i n t he t ex tb oo k i s wrong

17

Figure 2.6: 8

18

Figure 2.7: 9

19


1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32


// giv en

lambda=1.3; / / w a ve l en g th o f o p e r a t i o n i n um n1=1.5; // r e f r a c t i v e i nd e x o f c o r e n2=1.48; // r e f r a c t i v e i n d ex o f c l a d d i n g k0=2*%pi/lambda; / / c o n s t a n t i n /m

// cas e −1 b=0.5 / / n o r m a li z e d p r o p a g a ti o n c o n s t a n t k0=2*%pi/lambda / / c o n s t a n t beta=k0* sqrt (n2^2+b*(n1^2-n2^2)) / / p r o p a g a t i o n constant mprintf ( ” P r o p a g a t i o n c o n s t a n t =% f ra d /um” ,beta) //The a ns we rs v ar y d ue t o ro un d o f f e r r o r // cas e −2 // giv en lambda=1.3; / / w a ve l en g th o f o p e r a t i o n i n um n1=1.5; // r e f r a c t i v e i nd e x o f c o r e n2=1.48; // r e f r a c t i v e i n d ex o f c l a d d i n g k0=2*%pi/lambda; / / c o n s t a n t i n /m b=0.5 / / n o r m a li z e d p r o p a g a ti o n c o n s t a n t k0=2*%pi/lambda / / c o n s t a n t b=(((n1+n2)/2)^2-n2^2)/(n1^2-n2^2) / / n o r m a l i z e d p r o p a g a ti o n c o n s t a n t mprintf ( ” \ n P r o p ag a t i o n c o n s t a n t =%f ” ,b) / / The a n s w e r s v a ry due t o r oun d o f f e r r o r // cas e −3 // giv en lambda=1.3; / / w a ve l en g th o f o p e r a t i o n i n um n1=1.5; // r e f r a c t i v e i nd e x o f c o r e n2=1.0; // r e f r a c t i v e i nd e x o f c la d d i n g

20

Figure 2.8: 10 33 34 35 36

k0=2*%pi/lambda; / / c o n s t a n t i n /m b=0.5 / / n o r m a li z e d p r o p a g a ti o n c o n s t a n t k0=2*%pi/lambda / / c o n s t a n t beta=k0* sqrt (n2^2+b*(n1^2-n2^2)) / / p r o p a g a t i o n

constant 37 mprintf ( ” \ n P r o p a g a t i o n c o n s t a n t =%f r a d /um” ,beta) // The a ns we rs v ar y d ue t o rou nd o f f e r r o r


1 / / O p t i c a l F i b e r c om mu ni ca ti on by A s e l v a r a j a n

21

2 3 4 5 6 7 8 9 10 11 12

/ / e xa mp le 2 . 1 0 //OS=Windows XP sp 3 // S c i l a b v e r s i o n 5 . 5 . 1 clc ; c l e ar a ll ;

// giv en // cas e −1

n1=1.49; // r e f r a c t i v e i nd ex o f c o r e n2=1.46 // r e f r a c t i v e i nd ex o f c l a d di n g c=3*10^5; // s pe ed o f l i g h t i n Km/ s t1=n1/c; // t im e d el a y f o r o ne t r a v e l i n g a lo ng a x i s i n

s /Km 13 t2=(n1^2/n2)/c // t im e d el ay f o r o ne t r a v e l i n g a lo ng

14

15

16 17 18 19 20 21

22

23

p a t h t ha t i s t o t a l l y r e f l e c t i n g a t t h e f i r s t i n t e r f a c e i n s /km mprintf ( ” t i m e d el ay f o r t r a v e l i n g a lo ng a x i s =%f u s / Km” ,t1*1e6) // m u l t i p l i c a t i o n by 1 e 6 t o c o nv e r t t he u n i t f r o m s /Km t o u s /Km t r a v e l i n g a lo ng p ath t h at mprintf ( ” \ n t i m e d e la y f o r i s t o t a l l y r e f l e c t i n g at the f i r s t i n t e r f a ce = %fus/km” ,t2*1e6) // m u l t i p l i c a t i o n by 1 e 6 t o c o n v e r t t h e u n i t f ro m s /Km t o u s /Km // cas e −2 n1=1.47; // r e f r a c t i v e i nd ex o f c o r e n2=1.46 // r e f r a c t i v e i nd ex o f c l a d di n g c=3*10^5; // s pe ed o f l i g h t i n Km/ s t1=n1/c; // t im e d el a y f o r o ne t r a v e l i n g a lo ng a x i s i n t2=(n1^2/n2)/c // t im e d el ay f o r o ne t r a v e l i n g a lo ng p a t h t ha t i s t o t a l l y r e f l e c t i n g a t t h e f i r s t interface mprintf ( ” \ n t i m e d e l a y f o r t r a v e l i n g a lo n g a x i s =%f u s /Km” ,t1*1e6) // m u l t i p l i c a t i o n by 1 e6 t o c o nv e r t t h e u n i t f ro m s /Km t o u s /Km mprintf ( ” \ n t i m e d el ay f o r t r a v e l i n g a lo ng p a t h t ha t i s t o t a ll y r e f l e c t i n g at the f i r s t i n t er f a ce = %fus/km” ,t2*1e6) // m u l t i p l i c a t i o n by 1 e 6 t o c o n v e r t t h e u n i t f ro m s /Km t o u s /Km

24

22

25 / /The a ns we r p r ov i de d i n t he t ex tb o ok

h as g ot wrong u n i t

23

i s wrong i t

Chapter 3 Fiber optic technology


1 2 3 4 5 6 7 8 9 10 11

/ / O p t i c a l F i b e r c om mu ni ca ti on by A s e l v a r a j a n //example //OS=Windows XP sp 3 // S c i l a b v e r s i o n 5 . 5 . 1 clc ; c l e ar a ll ;

12 13

// giv en PL=1; // l e n g t h o f p re fo rm i n m PD=25e-3; // d a im e te r o f p re fo rm i n m OD=125e-6; // o u t er d ai me te r o f o p t i c a l f i b e r i n m V=%pi*((PD/2)^2)*PL; // v olume o f P re fo rm c y l i n d e r i n mˆ3 L=V/(%pi*((OD)^2)); // Le ng t h o f o p t i c a l f i b e r i n m mprintf ( ” L e ng th o f o p t i c a l f i b e r =%fKm” ,L/1e3); // d i v i s i o n by 1 e3 t o c o nv e r t u n it from m to Km


24

Figure 3.1: 1

25

1 2 3 4 5 6 7 8 9 10 11 12


// giv en

NA1=0.2; // n u m e r ic a l a p pe r t u r e o f f i b e r 1 NA2=0.1; // n u m e r ic a l a p pe r t u r e o f f i b e r 2 D1=12; // c or e d a im e t e r o f f i b e r 1 i n um D2=6; // c or e d ai m et e r o f f i b e r 2 i n um Losses=20* log10 (NA1/NA2)+20* log10 (D1/D2); // t o t a l

f i b e r t o f i b e r c o u p l i n g l o s s e s due t o NA mismatch and s i z e m is ma tc h 13 mprintf ( ” t o t a l l o s s e s =%fdB ” ,Losses);

26

Figure 3.2: 2

27

Chapter 4 Optical sources and transmitter circuits


1 2 3 4 5 6 7 8 9


// giv en tau_r=12*10^-9 // r a d i a t i v e r ec o m b i n at i o n t im e i n s tau_nr=35*10^-9 //non− r a d i a t i v e r ec o m b i n at i o n t i me i n

s 10 11 12 13 14

n1=3.5 // r e f r a c t i v e i nd ex o f s em i c on du ct o r n2=1 // r e f r a c t i v e i nd ex o f a i r d=0.4*10^-6 // a c t i v e l a t e r t h i c k n e s s i n m V =8 / / r e c o mb i n a t io n v e l o c i t y eta_int=1/(1+(tau_r/tau_nr)) / / i n t e r n a l qu antu m

efficiency 15 tau=1/((tau_r^-1)+(tau_nr^-1)+(2*V/d)) / / t o t a l

28

Figure 4.1: 1

29

16 17 18 19 20

21

22 23

r e co m b in a ti o n t im e i n s f= sqrt (3)/(2*%pi*tau) / / b a n dw i dt h i n Hz F3=((n1-n2)^2/(n1+n2)^2) // f r e s n e l r e f l e c t i o n eta_ext=eta_int*(1-F3) // e x t e r n a l quantum e f f i c i e n c y mprintf ( ” i n t e r n a l quantum e f f i c i e n c y =%f ” ,eta_int) // The a ns we rs v ar y d ue t o rou nd o f f e r r o r mprintf ( ” \ n t o t a l r e c o m bi n a t i on t im e =%f n s ” ,tau*1e9) // m u l t i p l i c a t i o n by 1 e9 t o c on v e rt u n i t fro m s t o n s // The a ns we rs v ar y d ue t o r ou nd o f f e r r o r mprintf ( ” \ nba ndw idt h =%f MHz” ,f*1e-6) // m u l t i p l i c a t i o n by 1 e−6 t o c o nv e r t u n it fro m Hz t o MHz/ // The a n sw er s v ar y du e t o r ou nd o f f e r r o r mprintf ( ” \ n f r e s n e l r e f l e c t i o n =%f ” ,F3) / / The a n s w e r s v a r y due t o ro un d o f f e r r o r mprintf ( ” \ n e x t e r n a l quantum e f f i c i e n c y =%f ” ,eta_ext) // The a ns we rs v ar y d ue t o ro und o f f e r r o r


1 2 3 4 5 6 7 8 9 10 11 12 13 14


// giv en lambda=1.3 // w av el en gt h o f l a s e r i n um w =5 // a c t i v e l a y e r w id th i n um d =2 // a c t i v e l a y e r t h i c k n e s s i n um n1=3.5 // r e f r a c t i v e i nd ex o f c o r e n2=3.49 // r e f r a c t i v e i nd ex o f c l a d di n g

//to find k0=2*%pi/lambda / / p r o p a g a t i o n

30

constant

Figure 4.2: 2

31

15 16 17 18

row=0.3 // c o n fi n e me n t f a c t o r neff= sqrt (n2^2+row) // e f f e c t i v e r e f r a c t i v e i n d ex D=k0*d*( sqrt (n1^2-n2^2)) // n o r m al i z e d t h i c k n e s s W=k0*w*( sqrt (neff^2-n2^2)) / / n o r m a l i z e d w i dt h / / t h e

a ns we r g i ve n i n t ex t bo o k i s wrong 19 Wlat=w*( sqrt (2* log (2)))*(0.32+2.1*(W^-1.5)) / / F u l l

20

21 22

23

24

w id th l a t e r a l a t h a l f maximum i n um/ t h e a ns we r g i ve n i n t ex tb oo k i s wrong Wtra=d*( sqrt (2* log (2)))*(0.32+2.1*(D^-1.5)) / / F u l l w id th t r a n s v e r s e a t h a l f maximum i n um/ t h e a ns we r g i ve n i n t ex t bo o k i s wrong mprintf ( ” N o r m a l iz e d t h i c k n e s s =%f ” ,D) / / The a n s w e r s v a r y due t o ro un d o f f e r r o r mprintf ( ” \n N o r m a l i ze d w i dt h =%f ” ,W) // m u l t i p l i c a t i o n by 1 e 9 t o c o n ve rt u n i t fro m s t o n s / // t he a ns we r g i ve n i n t ex t bo o k i s wrong mprintf ( ” \ n F u l l w id th l a t e r a l a t h a l f maximum =%f um ” ,Wlat) // m u l t i p l i c a t i o n by 1 e−6 t o c on v e rt u n i t f ro m Hz t o MHz/ // / t h e a ns we r g i v e n i n t e xt b o ok i s w ro ng mprintf ( ” \ n F u l l w id t h t r a n s v e r s e a t h a l f maximum =%f um” ,Wtra) // m u l t i p l i c a t i o n by 1 e−6 t o c o nv e r t u n i t f ro m Hz t o MHz/ // / t h e a ns we r g i v e n i n t e xt b o ok i s wrong


1 2 3 4 5 6


32

Figure 4.3: 3

33

7 8 9 10 11 12 13 14 15 16 17 18 19

// giv en

c l e ar a ll ; Eg=1.3 / / band ga p e n er g y i n eV l=0.4 / / c a v i t y l e n g t h i n mm R1=0.5 // r e f l e c t i v i t i e s on en ds R2=0.5 // r e f l e c t i v i t i e s on en ds alpha=3 // l o s s c o e f f i c i e n t in /mm current_density=30*10^5 / / c u r r e n t d e n s i t y i n amp/mˆ 2 area=0.2*0.5*10^-6 // l a s e r a c t i v e a re a i n mˆ2

lambda=1.24/Eg // e m i s s i o n w a ve l en g th i n um gth=alpha+(1/(2*l))* log (1/(R1*R2)) / / T h r e sh o l d G ai n threshold_current=current_density*area / / t h r e s h o l d

c ur re nt i n A 20 mprintf ( ” E m i s s i o n w a v e l e n g t h =%f nm” ,lambda) // m u l t i p l i c a t i o n by 1 e 3 t o c o n v er t u n i t fro m um t o nm 21 mprintf ( ” \ nT hr es ho ld Gain=%f/mm” ,gth) 22 mprintf ( ” \ n T h r e s h o l d c u r r e n t =%f mA” , threshold_current*1e3) // f o r c o n v e r ti n g u n i t fr om A t o mA


1 2 3 4 5 6 7 8 9

/ / O p t i c a l F i b er c om mu ni ca ti on by A s e l v a r a j a n / / e xa mp le 4 . 4 //OS=Windows XP sp 3 // S c i l a b v e r s i o n 5 . 5 . 1 clc ; c l e ar a ll ;

// giv en c l e ar a ll ; lamda=0.85*10^-6 // w av el en gt h o f o p e r a t i on i n m

34

Figure 4.4: 4

35

10 delta_lamda=36*10^-9 // s p e c t r a l w i d th i n m 11 fractional_width=delta_lamda/lamda // f r a c t i o n a l wi dt h 12 mprintf ( ” F r a c t i o n a l w id th=%f p e r c e n t ” , fractional_width*100) // m u l t i p l i c a t i o n by 1 00 t o

r e p r e s e n t i n f o r m a t i on i n p e rc e n t ag e

36

Chapter 5 Optical Detectors and Receivers


1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17


// giv en

optical_power=10*10^-6 // o p t i c a l power i n W R=0.5 / / R e s p o n s i v i t y i n A/W Is=optical_power*R // s h o t n o i s e c u r re n t i n A Id=2*10^-9 // d ar k c u r r e n t i n A Rl=1e6 // Load r e s i s t a n c e i n ohm B=1e6 / / b a n dw id t h i n Hz T=300 / / T em pe ra tu re i n K K=1.38*10^-20 / / Bo ltz ma n c o n s t a n t i n m2 g s −2 K−1 q=1.609*10^-19 // c ha r ge o f a e l e c t r o n i n Coulombs

37

Figure 5.1: 1

38

Figure 5.2: 2 18 Ith=4*K*T*B/Rl // Mean S qu ar e Therma l n o i s e

current in

A 19 SNR=(Is^2)/(2*q*(Is+Id)+Ith) // S i g n a l t o n o i s e r a t i o 20 mprintf ( ” T her ma l n o i s e c u r r e n t =%f ∗ 10ˆ −18A” ,Ith *10^18) 21 mprintf ( ” \ n Sh ot n o i s e c u r r e n t =%f ∗ 10 ˆ −6A” ,Is*10^6) 22 mprintf ( ” \ n S i g n a l t o n o i s e r a t i o =%fdB ” ,10* log10 (SNR) ) // The a ns we rs v ar y due t o ro un d o f f e r r o r


39

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19


// giv en

eta=0.6 // quantum e f f i c i e n c y Po=10*10^-6 // o p t i c a l power i n W q=1.6*10^-19 // c ha r ge o f an e l c t r o n i n columb lambda=0.85*10^-6 / / w a v el e n g th i n m h=6.6*10^-34 / / p l a nc k ’ s c o n s t a n t c=3*10^8 // v e l o c i t y o f l i g h t i n m/ s Rl=50 / / l o a d R e s i s t a n c e i n ohm R=(q*eta*lambda)/(h*c) // r e s p o n s i v i t y i n A/W I=R*Po // c u r r e nt i n A V=Rl*I / / V o l ta g e i n V mprintf ( ” R e s p o n s i v i t y =%f ” ,R ) mprintf ( ” \ nCurrent=%fuA” ,I*10^6) // m u l t i p l i c a t i o n by

1 e6 t o c o n v er t u n i t fro m A t o uA 20 mprintf ( ” \ nVoltage=%fmV” ,V*10^3) // m u l t i p l i c a t i o n by 1 e 6 t o c o n ve r t u n i t fro m V t o mV


1 2 3 4 5 6 7 8


// giv en tau_tr=2*1e-9 // t r a n s i t t i m e i n s e c

40

Figure 5.3: 3

41

Figure 5.4: 4 9 10 11 12 13

Rl=50 // l o a d r e s i s t a n c e i n ohm Cd=3*1e-12 // J u nc t io n c a p a c i t a n ce i n f a r a d tau=2*Rl*Cd // C i r c u i t t i me c o ns t an t i n s e c f3dB=(0.35/tau_tr) / / 3dB b a nd w id t h i n Hz mprintf ( ” C i r c u i t t im e c o n s t a n t =%f n s ” ,tau*1e9) //

m u l t i p l i c a t i o n by 1 e 9 t o c on v e rt u n i t fro m s t o ns 14 mprintf ( ” \n3dB ba nd wi dt h=%fMHz” ,f3dB*1e-6) // m u l t i p l i c a t i o n by 1 e−6 t o c o nv e r t u n it fro m Hz t o MHz

42


1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18


// giv en

I=100*1e-9 // c u r r e nt i n A P=5*1e-9 / / I n c i d e n t p ower i n W h=6.6*10^-34 / / p l a nc k ’ s c o n s t a n t c=3*10^8 // v e l o c i t y o f l i g h t i n m/ s q=1.6*10^-19 // c ha r ge o f an e l c t r o n i n columb eta=0.7 // quantum e f f i c i e n c y lambda=1.5*10^-6 / / w a v el e n g th i n m R=I/P; / /APD r e s p o n s i v i t y i n A/W M = ( R * h * c ) /( q * e t a * l a m bd a ) ; // M u l t i p l i c a t i o n f a c t o r mprintf ( ” R e s p o n s i v i t y =%f ” ,R ) mprintf ( ” \ n M u l t i p l i c a t i o n f a c t o r =%f” ,M)


1 2 3 4 5 6 7 8 9 10


// giv en h=6.6*10^-34 / / p l a nc k ’ s c o n s t a n t c=3*10^8 // v e l o c i t y o f l i g h t i n m/ s q=1.6*10^-19 // c ha r ge o f an e l c t r o n i n columb

43

Figure 5.5: 5

44

11 12 13 14 15 16 17

e l e n g th th i n m lambda=0.85*10^-6 / / w a v el I=0.1 / / i n c i d e n t l i g h t i n t e n s i t y i n mW/mm2 t o c u rr r r e n t i n p in in i n A Iph1=10*1e-6 / / p h o to Iph2=500*1e-6 / / p h o t o c u r r e n t i n APD i n A A=0.2 / / d e t e c t o r a r e a i n mm2 Po w e r s e e n b y d e t e c t o r i n mW P = I * A / / Po photons_generated=P*1e-3/(h*c/lambda) / / p h o t o n s

Generated 18 Rate=Iph1/q / / r a t e o f c a r r i e r g e n e r a t i o n f o r p i n 19 eta=Rate/photons_generated; / / Qu Qu a n t u m e f f i c i e n c y f o r pin 20 M=Iph2/Iph1 / / M u l t i p l i c a t i o n f a c t o r 21 mprintf ( ’ Qu Q u a n tum e f f i c i e n c y i s =% =% f ’ ,eta); //The a ns n s we w e rs r s v ar a r y d ue ue t o r o u n d o f f e r r o r 22 mprintf ( ’ \ n A va v a la l a nc n c he h e m u l t i p l e f a c t o r =% =% f ’ ,M);

45

Chapter 6 Integrated Optics and Photonic Circuits


1 2 3 4 5 6 7 8 9 10 11

/ / O p t i c a l F i b e r c om o m mu m u ni n i ca c a ti t i on on by A s e l v a r a j a n / / e xa x a mp m p le le 6 . 1 //OS= //OS =Window Windowss XP sp 3 // S c il a b v e rs i o n 5 . 5 . 1 clc ; c l e ar a r a ll ll ;

// giv en

lamda=1.55; / / w a v e l e n g t h i n um F i l m r e f r a c t i v e i nd n d ex ex n1=1.51; / / Fi n d ex ex n2=1.5; / / s u b s t r a t e r e f r a c t i v e i nd t=(lamda)/(2*%pi* sqrt (n1*n1-n2*n2)); / / T h i c k n e s s o f

f i l m i n um um 12 mprintf ( ’ F i l m t h i c k n e s s =% =%fum ’ ,t);

46

Figure 6.1: 1

47

Figure 6.2: 2

48


1 2 3 4 5 6 7 8 9 10 11 12 13 14 15


// giv en b=0.5 / / n o r m a li z e d p r o p o a g at i o n c o n s t a n t V=(2* atan (b/(1-b))/( sqrt (1-b))) / / n o r m a l i z e d frequency mprintf ( ’ N o r m a l i z e d f r e q u e n c y =%f ’ ,V) lamda=1.3; / / w a v e l e n g t h i n um n1=2.21; // Fi lm r e f r a c t i v e i nd ex n2=2.2; // s u b s t r a t e r e f r a c t i v e i nd ex t=(lamda)/(2*%pi* sqrt (n1*n1-n2*n2)); / / T h i c k n e s s o f f i l m i n um mprintf ( ’ \ n F i l m t h i c k n e s s =%fum ’ ,t);


1 2 3 4 5 6 7 8


// giv en lamda=1.3; / / w a v e l e n g t h i n um

49

Figure 6.3: 3

50

Figure 6.4: 4 9 10 11 12 13 14

nf=1.51; // Fi lm r e f r a c t i v e i nd ex t=1.5; // F ilm t h i c k n e s s i n um ns=1.5 // Waveguide r e f r a c t i v e i n de x na=1 // r e f r a c t i v e i nd ex o f a i r V=(2*%pi*t/lamda)* sqrt (nf^2-ns^2) //V−number a=(ns^2-na^2)/(nf^2-ns^2) / / a sy mm et ry p a r a m e t e r o f

t h e w a v eg u i d e 15 Vc = atan (a^0.5) // c u t o f f V−number 16 mprintf ( ”V−number=%f” ,V) 17 mprintf ( ” \ n as ym me tr y p a r a m e t er o f t h e w a v eg u i d e=%f ” , a) 18 mprintf ( ” \ n C u t o f f V−number=%f” ,Vc)

51


1 2 3 4 5 6 7 8 9 10 11 12 13 14 15


// giv en

delta_phi=%pi d=4*10^-6 // s e p e r a t i o n b et wee n e l e c t r o d e s n=2.2 // a pp ro xi ma te i n d er i n a bs en ce o f v o l t a g e r13=30*10^-12 / / p o p e r e l e c t r o o p t i c c o e f f i c i e n t row=0.4 // o v e r la p f a c t o r lambda=1300*1e-9 / / w a v el e n g th i n m L=8*10^-3 // l e n g th o f e l e c t r o d e i n m delta_n=delta_phi*lambda/(2*%pi*L) // c h an ge i n

r e f r a c t i v e i nd ex 16 V_pi=2*d*delta_n/(n^3*row*r13) // V ol ta he r e q u i r e d f o r

u s i n g t h e d e v i c e a s BPSK m od ul a to r 17 mprintf ( ” V ol ta ge r e q u i r e d f o r u s i n g t h e d e v i c e a s BPSK mo du la to r=%fV” ,V_pi) 18 mprintf ( ” \ n Vo lt ag e l e n g t h p ro du ct f o r u n it l e ng t h i s =%fVm” ,V_pi)


1 / / O p t i c a l F i b e r c om mu ni ca ti on by A s e l v a r a j a n 2 / / e xa mp le 6 . 5 3 //OS=Windows XP sp 3

52

Figure 6.5: 5

53

4 5 6 7 8 9 10 11 12 13

// S c i l a b v e r s i o n 5 . 5 . 1 clc ; c l e ar a ll ;

// giv en

d=10*10^-6 // s e p e r a t i o n b et we en e l e c t r o d e s ne=2.2 // a pp ro xi ma te i n d er i n a bs en ce o f v o l t a g e r33=32*10^-12 / / p o p e r e l e c t r o o p t i c c o e f f i c i e n t lambda=1*1e-6 / / w a v el e n g th i n m L=5*10^-3 // l e n g th o f e l e c t r o d e i n m V=d*lambda/(2*%pi*ne^3*r33*L) // V ol ta he r e q u i r e d f o r

u s i n g t h e d e v i c e a s BPSK m o du la to r 14 mprintf ( ” V ol ta ge r e q u i r e d f o r u s i n g t h e d e v i c e a s BPSK mo du la to r=%fV” ,V) // t he a ns we r i s d i f f e r e n t b ec au se o f r o un di ng o f f e r r o r


1 2 3 4 5 6 7 8 9 10


// giv en delta_L=1/100 // e r r o r i n e f f e c t i v e i n t e r a c t i o n l e n g t h P=(%pi/2*delta_L)^2 // c r o s s t a l k power o ut pu t i n W mprintf ( ” c r o s s t a l k p ow er o u t pu t=% fx1 0ˆ−4W” ,P*10^4);

// m u l t i p l i c a t i o n by 1 0 ˆ4 t o c o nv e r t u n it fro m W t o 10ˆ−4 W 11 PdB=10* log10 (P ) / / p ow er i n dB 12 mprintf ( ” \ n c r o s s t a l k p ow er o u t p u t=%fdB ” ,PdB)

54

Figure 6.6: 6

55

Chapter 7 Wavelength Division Multiplexing


1 2 3 4 5 6 7 8 9 10 11 12 13 14


// giv en

delta_lambda=60e-9; // d e l t a lambda i n m lambda=1550e-9; / / w a v el e n g th i n m c=3e8 // v e l o c i t y o f l i g h t i n m/ s CS=75*1e9 // C ha nn el s p a c i n g i n Hz Power_margin=30 / / p ow er m ar gi n i n dB Fiber_loss=0.25 / / f i b e r l o s s i n dB/Km channel_capacity=2.5*1e9 / / c h a n n e l c a p a c i t y STM−16 i n

bps 15 delta_f=(c*delta_lambda)/lambda^2; / / f r e q u e n c y

b a nd w id t h i n Hz 56

Figure 7.1: 1

57

16 transmission_distance=Power_margin/Fiber_loss //

T ra n sm i ss i on d i s t a n c e i n Km 17 No_channels= round (delta_f/CS); //No . o f c h a nn e l s 18 distance_bitrate_product=No_channels* channel_capacity*transmission_distance / / d i s t a n c e

b i t r a t e p r od u ct i n bpsKm 19 mprintf ( ” f r e q u e n c y b a n d wi d t h =%f x 1 0 ˆ 1 2 Hz ” ,delta_f/1 e12) // // d i v i s i o n by 1 e 12 t o c o n v er t u n it from Hz t o 1 0ˆ 12 Hz 20 mprintf ( ” \ n T r a n s m i s s i o n d i s t a n c e =%f Km” , transmission_distance) 21 mprintf ( ” \nNo . o f c h a n n e l s =%i ” ,No_channels) 22 mprintf ( ” \ n D i s t a n c e b i t r a t e p r o d u ct =%f T b i t s /sKm” , distance_bitrate_product/1e12) // // d i v i s i o n by 1

e 12 t o c o n v e r t u n i t f ro m b i t s /sKm t o T b i ts / sKm

58

Chapter 8 Coherent Optical Communication


1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

/ / O p t i c a l F i b e r c om mu ni ca ti on by A s e l v a r a j a n / / e xa mp le 8 . 1 //OS=Windows XP sp 3 // S c i l a b v e r s i o n 5 . 5 . 1

clc ; c l e ar a ll ; eta=0.8; // quantum e f f i c i e n c y o f d e t e c t i o n Ps=2e-9; // r e c e i v e d o p t i c a l power i n W h=6.62*1e-34; / / p l a n c k s c o n s t a n t lambda=1500*1e-9 / / w a v el e n g th i n m c=3*1e8 // v e l o c i t y o f l i g h t i n m/ s new=c/lambda; / / f r e q u e n c y i n Hz B=1e6; / / S i g n a l B an dw id th i n Hz SNR=(eta*Ps)/(2*h*new*B); // s i g n a l t o n o i s e r a t i o SNRdB=10* log10 (SNR) // s i g n a l t o n o i s e r a t i o i n dB ) mprintf ( ” s i g n a l t o n o i s e r a t i o =%f” ,SNR) / / t h e a n s w e r

i n t ex t bo o k i s wrong 59

Figure 8.1: 1

60

17 mprintf ( ” \ n s i g n a l

t o n o i s e r a t i o =%f dB” ,SNRdB) // the a ns we r i n t ex tb o ok i s wrong

61

Chapter 9 Optical Amplifiers


1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16


17

clc ; c l e ar a ll ; lambda=1.3*1e-6 / / w a v el e n g th i n m c=3*1e8 // v e l o c i t y o f l i g h t i n m/ s SNRoutdB=30 // s i g n a l t o n o i s e r a t i o a t o ut pu ti n dB SNRout=10^(SNRoutdB/10); // s i g n a l t o n o i s e r a t i o a t

o ut p ut n or ma l s c a l e new=c/lambda; / / f r e q u e n c y i n Hz h=6.6e-34; / / p l a n c k s c o n s t a n t P=0.5e-3; / / I n p u t p ow er i n W NFdB=4 // n o i s e f i g u r e i n dB NF=10^(NFdB/10); // n o i s e f i g u r e i n n o r ma l s c a l e SNRin=NF*SNRout // s i g n a l t o n o i s e r a t i o a t i np u t n or ma l s c a l e delta_Be=P/(2*h*new*SNRin); // r e c e i v e r b an dw id th i n 62

Figure 9.1: 1

63

Figure 9.2: 2 Hz 18 mprintf ( ’ S i g n a l t o n o i s e r a t i o a t I np ut=%f ’ ,SNRin) 19 mprintf ( ’ \ n R e c i e v e r b a n d wi d t h i s =% fx 10 ˆ 1 4 Hz ’ , delta_Be/1e14); // d i v i s i o n by 1 e 14 t o c o n ve rt t h e

u n i t f ro m Hz t o 1 0ˆ 14 Hz 20 / / The a ns we r g i ve n i n t ex t bo o k i s wrong


1 / / O p t i c a l F i b e r c om mu ni ca ti on by A s e l v a r a j a n 2 / / e xa mp le 9 . 2

64

3 4 5 6 7

//OS=Windows XP sp 3 // S c i l a b v e r s i o n 5 . 5 . 1 clc ; c l e ar a ll ; PASE=1e-3; // a m p l i f i e d s p on t an eo u s e m i s s io n power i n

W 8 Gdb=20; // o p t i c a l a m p l i f i e r g ai n i n dB 9 G=10^(Gdb/10); // o p t i c a l a m p l i f i e r g a i n i n n o r m a l

scale 10 11 12 13

delta_newbynew=5e-6; / / f r a c t i o n a l b an dw id th h=6.6e-34; / / p l a nc k ’ s c o n s t a n t ns=PASE/((G-1)*h/delta_newbynew); // n o i s e f a c t o r mprintf ( ’ n o i s e f a c t o r i s =%fx10 ˆ 21 ’ ,ns/1e21); //

d i v i s i o n by 1 e2 1 t o c on v e rt t he u n i t from Hz t o 1 0 ˆ 21 Hz 14 / / The a ns we r g i ve n i n t ex t bo o k i s wrong


1 2 3 4 5 6 7 8 9 10 11 12 13


clc ; c l e ar a ll ; L=50 // l i n k l e n g th i n Km Fiber_loss=0.2 // f i b e r l o s s i n dB/Km Req_Gain=Fiber_loss*L / / r e q u i r e d G ai n Fn1db=5 // N oi se f i g u r e i n dB Fn2db=5 // N oi se f i g u r e i n dB Fn3db=5 // N oi se f i g u r e i n dB Fn1=10^(Fn1db/10); // N oi se f i g u r e i n n o rm a l s c a l e

a l l a m p li f ie r s 65

for

Figure 9.3: 3

66

14 Fn2=10^(Fn2db/10); // N oi se f i g u r e

i n n o rm a l s c a l e f o r

a l l a m p li f ie r s 15 Fn3=10^(Fn3db/10); // N oi se f i g u r e

i n n o rm a l s c a l e f o r

a l l a m p li f ie r s 16 G1=10^(Req_Gain/10) // g a in i n n or ma l s c a l e 17 G2=10^(Req_Gain/10) // g a in i n n or ma l s c a l e 18 Fneff=Fn1+(Fn2/G1)+(Fn3/(G1*G2)); // E f f e c t i v e

noise

figure 19 SNRindb=30; // S i g n a l t o n o i s e r a t i o a t i np ut i n dB 20 SNRout=10^(SNRindb/10)/Fneff; // S i g n a l t o n o i s e r a t i o

a t o ut pu t i n dB 21 22 23 24

SNRoutdb=10* log10 (SNRout); mprintf ( ” R e q u i r e d G a in=% f” ,Req_Gain) mprintf ( ” \ n E f f e c t i v e n o i s e f i g u r e =%f ” ,Fneff) mprintf ( ” \ n S i g n al t o n o i s e r a t i o a t o ut pu t =%f dB” , SNRoutdb)

67

Chapter 10 Photonic Switching


1 2 3 4 5 6 7 8 9 10

/ / O p t i c a l F i b e r c om mu ni ca ti on by A s e l v a r a j a n / / e xa mp le 1 0 . 1 //OS=Windows XP sp 3 // S c i l a b v e r s i o n 5 . 5 . 1

clc ; c l e ar a ll ; Xx=-30 // c r o s s t a l k i n dB L=0.3 // t y p i c a l v a lu e N =5 / / no . o f s w i t c h e s Nb+Nc SXR=Xx-L*(N)-10* log10 (5*(10^(-L*N/10))/N) / / S i g n a l

power t o n o i s e power i n dB 11 mprintf ( ’ Minimum and maximum SXR v a l u e s=%fdB ’ ,SXR)


68

Figure 10.1: 1

69

Figure 10.2: 2

70

1 2 3 4 5 6 7 8 9 10 11 12 13

/ / O p t i c a l F i b e r c om o m mu m u ni n i ca c a ti t i on on by A s e l v a r a j a n / / e xa x a mp m p le le 1 0 . 2 //OS= //OS =Window Windowss XP sp 3 // S c il a b v e rs i o n 5 . 5 . 1

clc ; c l e ar a r a ll ll ; o w er er b u dg d g e t i n dB PB=40 / / p ow s s um um e d x=-30 / / c r o s s t a l k i n dB a ss no . o f s w i t c h e s N =4 / / no dB Lin=1 / / i n s e r t i o n l o s s o f i n dB a s e i n s e r t i o n l o s s o f i n dB dB Linw=Lin*N / / w o r s t c as o r st s t c a se s e c o n n ec e c t o r l o s s i n dB Lc=2 / / w or h e w or o r st st c as e L=Linw+2*Lc / / t o t a l p o w e r l o s t i n t he

s i g n a l path i n d dB B 14 Power_margin=PB-L / / p ow o w er er m ar a r gi g i n i n dB 15 16 17 18 19 20 21

K=0; f o r i=1:N K=K+(((-1)^(i+1))*(10^(-x/10))î); end SbyN=10* log10 ( K ) / / S i g n a l p o w e r t o n o i s e p o w e r i n dB o w er e r t o n o i s e p ow o w er e r =%fdB ’ ,SbyN) mprintf ( ’ S i g n a l p ow nPower Margin =%fdB %fdB ’ ,Power_margin) //The mprintf ( ’ \ nPower

T ex e x tb t b oo o o k a n sw s w er e r i s w r on on g

71

Chapter 11 Fiber Optic Communication System Design


1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17

/ / O p t i c a l F i b e r c om o m mu m u ni n i ca c a ti t i on on by A s e l v a r a j a n / / e xa x a mp m p le le 1 1 . 1 //OS= //OS =Window Windowss XP sp 3 // S c il a b v e rs i o n 5 . 5 . 1

clc ; c l e ar a r a ll ll ; d t h i n MHz BW=7 / / b a n d w i dt dB SNR=60 / / s i g n a l t o n o i s e r a t i o i n dB n c h ed ed p o we we r i n dBm Pin=0 / / L a u nc c e LED i n n s Trise_source=20 / / r i s e t i m e a t s o u r ce i d th t h i n nm delta_lambda=20 / / s p e c t r a w id v e l en e n g th t h i n nm lambda=850; / / o p e r a t i n g w a ve Km/ s e c c=2.998*10^5; / / v e l o c i t y o f l i g h t i n Km FET r e s p o n s i v i t y i n A/W R=0.3 / / D e t e c t o r PIN FE de c a p ac i ta n c e i n p f Cdiode=3 / / d i o de trise_detector=1 / / r i s e t i m e a t d e t e c t o r i n n s S=-30 / / s e n s i t i v i t y i n dbm

72

Figure 11.1: 1

73

18 19 20 21 22 23 24 25 26 27 28 29 30 31

Lsplice=0.2 // s p l i c e l o s s i n dB/ c o n ne c to r NA=0.2 / / n u m e r i c a l a p e r t u r e f o r GI /MM n1=1.46 // r e f r a c t i v e i nd ex o f c o r e A =2 / / a t t e n u a t i o n i n dB /Km Ls=3 // l o s s due t o s o u r c e i n dB Ld=1 // l o s s due t o d e t e c t o r i n dB Psm=5 / / s y st e m m ar gi n i n dB c=3*10^8 // v e l o c i t y o f l i g h t i n m/ s

// sol uti on Available_power=Pin-S; // a v a i l a b l e power i n dB Total_loss=Ls+Ld+Psm; Power_left=Available_power -Total_loss; / / p o w e r l e f t

i n dB 32 33 34 35

L=(Power_left+Lsplice)/(Lsplice/2+2); tmod=L*10^3*(NA^2)/(2*c*n1); // modal d i s p e r s i o n i n s Bit_rate=1/tmod; // b i t r a t e i n bps mprintf ( ’ Maximum p e r m i s s i b l e l i n k l e n g t h i s =%fKm ’ ,L );

36 37 mprintf ( ’ \nMaximum p e r m i s s i b l e b i t r a t e i s =%fMbps ’ , Bit_rate/10^6); // d i v i s i o n by 1 0 ˆ 6 t o c o n v er t t he

u n i t from bps t o Mbps // t he a ns we r i s b ec au se o f r ou nd in g o f f

di ffe re nt


1 2 3 4 5

/ / O p t i c a l F i b e r c om mu ni ca ti on by A s e l v a r a j a n / / e xa mp le 1 1 . 2 //OS=Windows XP sp 3 // S c i l a b v e r s i o n 5 . 5 . 1 clc ;

74

Figure 11.2: 2

75

6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24

c l e ar a ll ; BW=7 / / b a n d w i dt h i n MHz SNR=60 // s i g n a l t o n o i s e r a t i o i n dB Pin=0 / / L a u nc h ed p o we r i n dBm Trise_source=4 // r i s e t i m e a t s o u r ce LED i n n s delta_lambda=1 // s p e c t r a w id th i n nm lambda=1300; // o p e r a t i n g w a ve l en g th i n nm c=2.998*10^5; // v e l o c i t y o f l i g h t i n Km/ s e c R=0.3 / / D e t e c t o r PIN FET r e s p o n s i v i t y i n A/W Cdiode=3 // d i o de c a p a c i t a n c e i n p f trise_detector=5 // r i s e t i m e a t d e t e c t o r i n n s F=2.1 // a m p l i f i e r n o i s e f i g u r e i n dB Camp=2 // a m p l i f i e r c a p a c i t a n c e i n p f L =2 / /minimum l i n k l e n g t h i n Km Lsplice=0.5 // s p l i c e l o s s i n dB/ c o n ne c to r NA=0.22 / / n u m e r i c a l a p e r t u r e f o r GI /MM BWGI=600 / / GI /MM f i b e r b a nd w id t h i n MHz F 3 d B o p t i c a l Te=630 / / t e m p er a t e i n K e l v i n K = 1 . 3 80 6 4 8 52 * 1 0 - 23 // b ol tz ma n c o n st a n t i n m2 k g s −2

K−1 25 / / s o l u t i o n 26 Rload=1/(2*%pi*(Cdiode+Camp)*BW)*10^6 //maximum lo ad

r e s i s t a n c e i n ohm A ct ua l v a l u e 27 Rload=4300 / / a p p ro x im a te d v a l u e i n ohm 28 BWRx=1/(2*%pi*(Cdiode+Camp)*Rload) / / r e c e i v e r BW i n Hz 29 SbyN=10^(SNR/10) / /SNR i n n or ma l s c a l e 30 Pmin=10* log10 ( sqrt (SbyN*4*K*Te*BW/(0.5*Rload*R^2)))

/ / i n p u t p ow er i n W 31 L1=Pmin/0.2 // p ower b ud ge t l i m i t e d l i n k l e n g t h i n Km 32 mprintf ( ’ Maximum p e r m i s s i b l e l i n k l e n g t h i s =%fKm ’ , L1); 33 34 Trise_required=(0.35/BW)*10^3 / / B an dw it h b u d g e t t i n g

r i s e t i m e r e q u i r e d i s r i s e t i m e r e q u i r e d i n n s // m u l t i p l i c a t i o n by 1 0 ˆ 3 t o c o nv e r t msec t o n s 35 Trise_receiver=2.19*Rload*(Cdiode+Camp)*10^-3 / / r i s e t i m e o f r e c e i v e r i n n s // m u l t i p l i c a t i o n by 1 0 ˆ 3 t o 76

c o n ve r t msec t o n s 36 Trise_fiber= sqrt (Trise_required^2-Trise_receiver^2Trise_source^2) // f i b e r d i s p e r s i o n i n n s 37 / / f o r GI 38 f3dB_electrical=0.71*BWGI; // 3dB e l c t r i c a l BW i n

MHzKm 39 t_intra_modal=1 / / i n t r a modal d i s p e r s i o n i n n s /Km 40 t_inter_modal=3 / / i n t e r mo d a l d i s p e r s i o n i n n s /Km 41 t_fiber_GI= sqrt (t_intra_modal^2+t_inter_modal^2); //

r i s e t i m e o f f i b e r i n n s /Km 42 L2=Trise_fiber/t_fiber_GI // l i n k l e n g t h i n Km 43 mprintf ( ’ \n Maximum p e r m i s s i b l e l i n k l e n g t h f o r GI i s =%fKm ’ ,L2);

77

Chapter 13 Video Transmission


1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18


clc ; c l e ar a ll ; Sigma_s=0.1 // s o u r c e d i s p e r s i o n i n ns Sigma_D=0.1 // d e t e c t o r d i s p e r s i o n i n n s Sigma_F=0.05 // f i b e r d i s p e r s i o n i n n s bitrate=622 / / b i t r a t e i n Mbps STM_rate=250 / / 4 c h a n n e l VSB PCM Power_margin=30 / / p ow er m ar gi n i n dB system_margin=6 / / s y st e m m ar gi n i n dB Average_loss=0.6 / / a v e r a g e l o s s i n dB/Km

// sol uti on Sigma_max=STM_rate/bitrate //max d i s p e r s i o n a l l ow e d L2 = sqrt ((Sigma_max -Sigma_s^2- Sigma_D^2)/(Sigma_F ^2))

// d i s p e r s i o n l i m i t e d maximum l e n g t h i n Km 78

Figure 13.1: 1

79

19 L1=(Power_margin -system_margin )/Average_loss //

A tt en ua ti o n l i m i t e d l e n g t h i n km 20 mprintf ( ” S i n ce d i s p e r s i o n l i m i t e d maximum l e n g t h i s l e s s t h a n A tt en ua ti o n l i m i t e d l e n g t h \ n so p r e s e nt s ys te m l e n g t h l i m i t i s =%fKm ” ,L2)

80

Chapter 14 Data Communication and LAN


1 2 3 4 5 6 7 8 9 10 11 12


clc ; c l e ar a ll ; N=256 / / no . o f n od es Lc=0.25 // l o s s p e r co up ; e r i n dB Power_margin=30 / / p ow er m ar gi n i n dB system_margin=6 / / s y st e m m ar gi n i n dB Average_loss=0.6 / / a v e r a g e l o s s i n dB/Km TxRX_powergain=32 // t r a n s m i t t e r t o r e c e i v e r power

g a i n i n dB 13 14 15 16 17 18

Avg_Tr_loss=0.5 / / a v e r ag e t r a n s m i t t e r

l o s s i n dB/Km

// sol uti on Nc = log2 (N ) // s i n c e 2 x2 c o u p l e r s a r e u se d Ns=N/2 // e ac h s t a ge c o u p l e r T_Nc=Nc*Ns // t o t a l no . o f c o u p l e r s

81

Figure 14.1: 1

82

19 Total_Lc=Nc*Lc // t o t a l c o u p le r l o s s i n dB 20 Permissible_loss= TxRX_powergain -Total_Lc //

p e r m i s s i b l e c a b l e l o s s i n dB 21 L=Permissible_loss/Avg_Tr_loss / / T r a n s m i s s i o n d i s t a n c e i n Km 22 mprintf ( ” T r a n s m i s s i o n d i s t a n c e =%fKm ” ,L)

83

Chapter 16 Soliton Communication Systems


1 2 3 4 5 6 7 8 9 10 11 12 13


clc ; c l e ar a ll ; lambda=850; / / o p e r a t i n g w a ve l en g th i n nm Beta2=-1 / / d i s p e r s i o n r e g i me p s ˆ 2 /Km Gama=2 // n o n l i n e a r i t y i n /W−Km TFWHM=10 // f u nd am en ta l s o l i t o n w id th i n p s To=TFWHM/1.763 // p u l s e wi dt h i n p s Ppeak=1/(Gama*(To^2)) / / p ea k p ow er i n W mprintf ( ” Peak p ow er r e q u i r e d t o m a i nt a in f u nd a me nt a l s o l i t o n=%fmW” ,Ppeak*10^3) // m u l t i p l i c a t i o n by

1 0 ˆ3 i s t o c o nv e r t t he u n i t fro m w t o mW

84

Figure 16.1: 1

85

Figure 16.2: 2


1 2 3 4 5 6 7 8

/ / O p t i c a l F i b e r c om mu ni ca ti on by A s e l v a r a j a n / / e xa mp le 1 6 . 2 //OS=Windows XP sp 3 // S c i l a b v e r s i o n 5 . 5 . 1 clc ; c l e ar a ll ; lambda=1.55; // o p e r a t i n g w a ve l en g th i n um Beta2=-1 / / d i s p e r s i o n r e g i me p s ˆ 2 /Km

86

Figure 16.3: 3 9 B=10 // b i t r a t e i n Gb/ s 10 two_qo=12 // s e p a r a t i o n b et we en two n e i g h b o u r i ng

s o l i t o n s i n n or ma li ze d u n i t s 11 LT=%pi* exp (two_qo/2)/(8*(two_qo/2)^2* abs (Beta2) *10^-24)/(B^2*(10^18)) // d i s t a n c e t r a n s m i s s i o n

l i m i t i n Km 12 mprintf ( ’ F or 10Gb/ s b i t r a t e , t r a n s m i s s i o n d i s t a n c e i s l i m i t e d t o =%f Km ’ ,LT) / / t h e a ns we r i s d i f f e r e n t b ec au se o f r o un di ng o f f


87

1 2 3 4 5 6 7 8 9 10


clc ; c l e ar a ll ; alpha=0.2 // f i b e r l o s s i n dB/Km LA=50 / / A m p l i f i e r s p a c i n g i n Km G=(alpha*LA) // g ai n i n f i b e r PbyPo=G* log (G)/(G-1) // M u l ti p l e o f power r e q u i r e d by

s i n gl e s o l it o n 11 mprintf ( ’ M u lt i pl e o f power r e q u i r e d by s i n g l e s o l i t o n =%f ’ ,PbyPo) // t h e a n s we r i s s l i g h t l y v a ri n g due t o r ou nd in g e r r o r


1 2 3 4 5 6 7 8 9


10 11 12

13

clc ; c l e ar a ll ; lambda=1.55; // o p e r a t i n g w a ve l en g th i n um LA=50 / / A m p l i f i e r s p a c i n g i n Km qo=6 // H a lf o f s e p a r a t i o n b etw ee n two n e i gh b o ur i n g

s o l i t o n s i n n or ma li ze d u n i t s Beta2=-1 / / d i s p e r s i o n r e g i me p s ˆ 2 /Km B=1/(4*(qo)^2* abs (Beta2)) / / b a n d w i dt h i n THz mprintf ( ’ C ommunication L in k b i t r a t e i s l i m i t e d t o = %f GHz ’ ,B*10^3) // M u l t i p l i c a t i o n by 1 0ˆ 3 t o c o n v e r t u n i t f r o n THz t o GHz / / t h e a n sw er i s wr on g 88

Figure 16.4: 4

89

Figure 16.5: 5


1 2 3 4 5 6 7 8

/ / O p t i c a l F i b e r c om mu ni ca ti on by A s e l v a r a j a n / / e xa mp le 1 6 . 5 //OS=Windows XP sp 3 // S c i l a b v e r s i o n 5 . 5 . 1 clc ; c l e ar a ll ; LT=10000 / / T r a ns m i s si o n d i s t a n c e i n Km alpha=0.2 // f i b e r l o s s i n dB/Km

90

Optical Fiber Communication_A. Selvarajan, S. Kar and T Srinivas

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