optical_fiber_communication

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Scilab Code for

Optical Fiber Communication

by Gerd Keiser 1

Created byProf. R. Senthilkumar

Institute of Road and Transport Technologyrsenthil [email protected]

Cross-Checked byProf. Saravanan Vijayakumaran, IIT Bombay

[email protected]

11 January 2011

1Funded by a grant from the National Mission on Education through ICT,http://spoken-tutorial.org/NMEICT-Intro. This Text Book Companion andScilab codes written in it can be downloaded from the website www.scilab.in



Book Details

Authors: G. Keiser

Title: Optical Fiber Communication

Publisher: Tata McGrawHill

Edition: 4th Edition, 8th Reprint

Year: 2010

Place: New Delhi

ISBN: 0-07-064810-7

1



Scilab numbering policy used in this document and the relation to theabove book.

Exa Example (Solved example)

Fig Code for Figure(Scilab code that is used for plotting the respective figureof the above book )

For example, Exa 4.56 means solve example 4.56 of the above book.

2



Contents

List of Scilab Codes 4

1 First chapter 2

2 Second chapter 7

3 Third chapter 11

4 Fourth chapter 16

5 Fifth chapter 22

6 Sixth chapter 26

7 Seventh chapter 31

8 Eight chapter 35

9 Ninth chapter 40

10 Tenth chapter 46

11 Eleventh chapter 54

12 Twelve chapter 59

13 Thirteen chapter 64

14 Fourteen chapter 68

3



List of Scilab Codes

Exa 1.1 Program to calculate time period and phase shift . . . 2Exa 1.2 Example 1.2 . . . . . . . . . . . . . . . . . . . . . . . 3Exa 1.4 Shannon Channel Capacity formula . . . . . . . . . . 3Exa 1.5 Capacity of a channel using Shannon’s formula . . . . 4Exa 1.6 Program to calculate attenuation loss of power . . . . 5Exa 1.7 Power gain calculation for a signal travelling from one

point to another point . . . . . . . . . . . . . . . . . . 5Exa 2.1 Critical Angle of incidence . . . . . . . . . . . . . . . 7Exa 2.2 Finding Critical angle, numerical aperture, acceptance

angle . . . . . . . . . . . . . . . . . . . . . . . . . . . 7Exa 2.3 Program to Calculate NORMALIZED FREQUENCY

’V’ and Numerical Aperture . . . . . . . . . . . . . . . 8Exa 2.4 Power flow in the core and cladding of step index fiber 8

Exa 2.5 Program to calculate Fiber Birefringence Betaf . . . 9Exa 3.1 Program to Find Attenuation in dB/km . . . . . . . 11Exa 3.2 To calculate input and output power in dBm . . . . . 11Exa 3.3 Rayleigh scattering loss . . . . . . . . . . . . . . . . . 12Exa 3.4 Program to calculate percent in decrease of number of

modes . . . . . . . . . . . . . . . . . . . . . . . . . . . 12Exa 3.5 Calculation of pulse broadening . . . . . . . . . . . . 13Exa 3.6 Calculation of bandwidth distance . . . . . . . . . . . 14Exa 3.7 Program to Find out the Material Dispersion . . . . . 14Exa 3.8 Program to Find out Waveguide Dispersion . . . . . . 15Exa 4.1 Program to find intrinsic carrier concentration . . . . 16

Exa 4.3 Finding Enegy gap and Wavelength . . . . . . . . . . 16Exa 4.4 Finding Enegy gap and Wavelength . . . . . . . . . . 17Exa 4.5 To find out the Internal Quantum Efficiency and Inter-

nal Power level of LED source . . . . . . . . . . . . . . 17

4



Exa 4.6 External Quantum Efficiency in percentage . . . . . . 18

Exa 4.7 Program to find Lasing Threshold gain . . . . . . . . 19Exa 4.8 Program TO Calculate Frequency Spacing and Wave-length Spacing . . . . . . . . . . . . . . . . . . . . . . 19

Exa 4.9 Calculation of number of half-wavelengths and wave-length spacing between lasing modes . . . . . . . . . . 20

Exa 5.1 Calculation of Lateral power distribution coefficient . 22Exa 5.2 Program to Calculate Optical Power Emitted from the

Light source and Optical power coupled to step-indexfiber . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

Exa 5.3 Fresnel reflection, power coupled and power loss . . . 23Exa 5.4 Power coupled between two graded index fibers . . . . 24

Exa 5.5 Loss between single mode fibers due to Lateral mis-alignment . . . . . . . . . . . . . . . . . . . . . . . . . 24

Exa 5.6 Loss between single mode fibers due to angular mis-alignment . . . . . . . . . . . . . . . . . . . . . . . . . 25

Exa 6.1 Cut-off wavelength of photodiode . . . . . . . . . . . 26Exa 6.2 Calculation of Quantum efficiency . . . . . . . . . . . 26Exa 6.3 Calculation of photocurrent . . . . . . . . . . . . . . 27Exa 6.4 Calculation of Responsivity of photodiode . . . . . . 27Exa 6.5 To find primary photocurrent and multiplication factor 28Exa 6.6 Mean-square shot noise current, Mean-square dark cur-

rent and Mean-Square thermal noise current . . . . . . 29Exa 6.7 Circuit bandwidth of a photodiode . . . . . . . . . . 30Exa 7.1 To find optimum decision threshold . . . . . . . . . . 31Exa 7.2 To find out signal-to-noise ratio and probability of error

for given ’Q’ . . . . . . . . . . . . . . . . . . . . . . . 31Exa 7.3 Plotting Bit Error Rate versus Q factor . . . . . . . . 33Exa 7.4 To find the energy of the photon incident on photodiode

and Minimum incident optical power . . . . . . . . . . 34Exa 8.1 Program to calculate the Total Optical Power loss . . 35Exa 8.2 Program to calculate the system margin . . . . . . . 35Exa 8.3 Program to calculate link rise time . . . . . . . . . . 36

Exa 8.4 Program to calculate link rise time . . . . . . . . . . 36Exa 8.5 Calculation of Number of bits affected by a burst error 37Exa 8.6 Program to find coefficients of generator polynomial . 37Exa 8.7 Program to find CRC(Cyclic Redundancy Check) . . 38Exa 8.8 Program to percentage of burst error detected by CRC 39

5



Exa 8.9 Percent overhead to the information stream Using Reed-

Solomon code for error correction . . . . . . . . . . . . 39Exa 9.1 Program to find Relative Intensity Noise (RIN) . . . . 40Exa 9.2 Program to Find limiting conditions for pin-photodiode 40Exa 10.1 Finding the center wavelength . . . . . . . . . . . . . 46Exa 10.2 Finding mean frequency spacing . . . . . . . . . . . . 46Exa 10.3 Program to find coupling ratio, Excess loss, Insertion

loss, Return loss of 2x2 Fiber coupler . . . . . . . . . . 47Exa 10.5 Finding output powers at output port of 2x2 coupler 48Exa 10.6 Program to find waveguide length . . . . . . . . . . . 48Exa 10.7 Program to find Excess loss, Splitting loss and total loss 49Exa 10.8 Program to Waveguide Length difference . . . . . . . 49

Exa 10.9 Fiber Bragg Grating: Peak Reflectivity, Coupling coef-ficient, full-bandwidth . . . . . . . . . . . . . . . . . . 50

Exa 10.10 Phased-Array-Based-Devices: Channel spacing in termsof wavelength and path-length difference . . . . . . . . 51

Exa 10.11 Phased-Array-Based Devices: Length difference betweenadjacent array waveguides . . . . . . . . . . . . . . . . 52

Exa 10.12 Maximum number of channels that can be placed inthe tuning range . . . . . . . . . . . . . . . . . . . . . 53

Exa 11.1 Program to calculate Photon density . . . . . . . . . 54Exa 11.2 Pumping rate and zero-signal gain . . . . . . . . . . . 54

Exa 11.3 Maximum input power and maximum output power . 55Exa 11.6 Optical Signal-to-noise ratio (OSNR) . . . . . . . . . 56Exa 11.7 Pump power of EDFA . . . . . . . . . . . . . . . . . 56Exa 11.8 OSNR for different ASE noise level . . . . . . . . . . 57Exa 11.9 Noise penalty factor . . . . . . . . . . . . . . . . . . . 57Exa 11.10 Upper bound on input optical signal power . . . . . . 58Exa 12.1 Effective length of fiber . . . . . . . . . . . . . . . . . 59Exa 12.2 Calculation of Stimulated Brillouin Scattering (SBS)

threshold power . . . . . . . . . . . . . . . . . . . . . 59Exa 12.3 Four-wave mixing-calculation of power generated due

to the interaction of signals at different frequencies . . 60

Exa 12.4 Full-width Half-Maximum (FWHM) soliton pulse nor-malized time . . . . . . . . . . . . . . . . . . . . . . . 61

Exa 12.5 Calculation of normalized distance parameter for dis-persion shifted fiber . . . . . . . . . . . . . . . . . . . 61

Exa 12.6 Program to calculate soliton peak power . . . . . . . 62

6



Exa 12.7 FWHM soliton pulse width and fraction of bit slot oc-

cupied by a soliton . . . . . . . . . . . . . . . . . . . . 62Exa 13.1 Calculation of power budget for optical link . . . . . . 64Exa 13.2 Calculation of Number stations for given loss . . . . . 65Exa 13.3 Calculation of worst case Dynamic Range . . . . . . . 66Exa 13.4 Calculation of power margin between transmitter and

receiver for Star architectures . . . . . . . . . . . . . . 66Exa 13.5 Determination of maximum length of multimode fiber

link . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67Fig 14.10 Performance Measurement and Monitoring for sce . . 68

1



21 // 1 . 0 0 0D−09

22 // p ha se s h i f t i n d e g r e e s23 // 9 0 .24 // p ha se s h i f t i n r a d i an s25 // 1 . 5 7 0 6 8 0 6

Scilab code Exa 1.2 Example 1.2

1 / / C ap ti on : Program t o c a l c u l a t e t im e p e r i o d and p ha s es h i f t

2 // Example1 . 13 / / P ag e 84 clear ;5 clc ;

6 close ;

7 f1 = 1 0^ 5; // f1 = 100KHz8 f2 = 1 0^ 9; // f2 = 1GHz9 T1 = 1/ f1 ;

10 T2 = 1/ f2 ;

11 p hi = ( 1/ 4) * 3 6 0;

12 p h i_ r ad = p hi / 5 7 .3 ;

13 disp ( T 1 , ’ Time p e r i od o f s i n e wave w it h f r eq u e nc y =

100 KHZ ’ )14 disp ( T 2 , ’ Time p e r i od o f s i n e wave w it h f r eq u e nc y = 1GHZ ’ )

15 disp ( p h i , ’ p ha se s h i f t i n d e gr e e s ’ ) ;

16 disp (phi _rad , ’ p ha se s h i f t i n r a di a n s ’ ) ;

17 / / R e s u l t18 / /Time p e r i o d o f s i n e wave w it h f r e q u e n c y = 10 0 KHZ19 // 0 . 0 0 0 0 120 / /Time p e r i o d o f s i n e wave w it h f r e q u e n c y = 1GHZ21 // 1 . 0 0 0D−0922 // p ha se s h i f t i n d e g r e e s

23 // 9 0 .24 // p ha se s h i f t i n r a d i an s25 // 1 . 5 7 0 6 8 0 6

3



Scilab code Exa 1.4

1 / / C a p t i o n : S ha nn on C h an n el C a p a c i t y f o r m u l a2 // Example1 . 43 / / p ag e 1 24 clear ;

5 clc ;

6 close ;

7 B = 10 ^6 ; / / B an dw id th o f n o i s y c h a n n e l 1 0MHZ8 S_N = 1; / / s i g n a l−to−n o i s e r a t i o n i s 19 C = B * log2 ( 1 + S _ N ) ;

10 disp (C , ’ The maximum c a p a c i t y f o r t h i s c h a nn e l i nb i t s / s e c C = ’ )

11 / / R e s u l t12 / /The maximum c a p a c i t y f o r t h i s c h a nn e l i n b i t s / s e c

C = 1 0 0 0 0 0 0 .

Scilab code Exa 1.51 / / C a p ti o n : C a p a ci t y o f a c h a n n e lu s i n g s ha nn on ’ s f o r m u l a

2 // Example1 . 53 / / p ag e 1 24 clear ;

5 clc ;

6 close ;

7 f Lo w = 3 * (1 0 ^6 ) ; / / l o w f r e q u e n c y = 3MHz8 f Hi gh = 4 *( 1 0^ 6) ; / / h i h g f r e q u e n c y = 4MHz9 S _N _d B = 2 0; / / s i g n a l −to−n o i s e r a t i o 20 dB

10 S _N = 1 0^ ( S _ N_ dB / 1 0) ;

11 B = fHigh - fLow ;

12 C = B * log2 ( 1 + S _ N ) ;

13 disp (B , ’ B a nd wi dt h i n Hz B = ’ )

14 disp (C , ’ C ap ac it y o f a c h an n el i n b i t s / s e c s C = ’ )

15 disp ( S _ N , ’ s i g n a l t o n o i s e r a t i o S/N = ’ )

16 / / R e s u l t17 // Bandwidth i n Hz B = 1 00 00 00 .18 // C ap ac it y o f a c ha nn el i n b i t s / s e c s C =

6 6 5 8 2 1 1 . 519 // s i g n a l to n o i s e r a t i o S/N = 1 0 0 .

4



Scilab code Exa 1.61 / / C a p ti o n : Pro gra m t o c a l c u l a t ea t t e n u a ti o n ( o r ) l o s s o s power

2 / / E xa mp le 1 . 63 / / p ag e 1 44 clear ;

5 clc ;

6 close ;

7 P 1 = 1; / / o ne w at t8 P2 = P1 /2; // r ed uc ed by h a l f v a lu e

9 A t te n_ d B = 1 0* log10 ( P 2 / P 1 ) ;10 disp (At ten_dB , ’ A t t en u a t io n i n dB = ’ ) ;

11 p o w er _ l os t = 1 0 ^( A t t e n _ dB / 1 0)

12 disp (power_lost , ’ The amount o f power l o s t = ’ ) ;

13 / / R e s u l t14 / / A t t e n u a t i o n i n dB = − 3 . 0 1 0 315 // The amount o f power l o s t = 0 . 5

Scilab code Exa 1.71 / / C ap ti on : Power g a i n c a l c u l a t i o nf o r a s i g n a l t r a v e l l i n g from

2 // one p o in t t o a no th er p o in t3 / / E xa mp le 1 . 74 / / p ag e 1 45 clear ;

6 clc ;

7 close ;

8 L o ss _ li n e1 = -9 ; //−9 dB9 A m p_ g ai n 2 = 1 4; / / 1 4 d B

10 L o ss _ li n e3 = -3 ; //−3 dB11 d B _ at _ l i ne 4 = L o s s _l i n e 1 + A m p _ ga i n 2 + L o s s _ li n e 3 ;

12 disp (dB_at_line4 , ’ The amount o f p ow er g a i n e d by as i g n a l t r a v e l l i n g from p oi nt 1 t o p oi nt 4 i n dB = ’)

13 / / R e s u l t

5



14 // The amount o f power g a in e d b y a s i g n a l t r a v e l l i n g

from p o i n t 1 t o p o i n t 4 i n dB = 2 .

6



Chapter 2

Second chapter

Scilab code Exa 2.1

1 // C a pt io n : C r i t i c a l A ng le o f i n c i d e n c e2 / / E xa mp le 2 . 13 / / p ag e 3 74 clear ;

5 close ;

6 clc ;

7 n1 = 1 .4 8;

8 n2 = 1 .0 0;

9 p hi c = asin ( n 2 / n 1 ) ;10 disp ( p h i c * 5 7 . 3 , ’ T o t a l I n t e r f l e c t i o n r e f l e c t i o n a ng le

: c r i t i c a l a n g l e o f i n c i d e n c e i n d e g r e e s ’ )

11 / / R e s u l t12 // T ot al I n t e r f l e c t i o n r e f l e c t i o n a n g l e : c r i t i c a l

a n gl e o f i n c i d e n c e 4 2. 5 09 77 3

Scilab code Exa 2.21 // C a pt io n : F in d in g C r i t i c a l a ng le ,n u me r ic a l a p er t ur e , a c ce p ta n c e a n g l e

2 / / E xa mp le 2 . 23 / / p ag e 4 54 clear ;

5 close ;

6 clc ;

7



7 n1 = 1 .4 8; // c o re r e f r a c t i v e i nd ex

8 n2 = 1 .4 6; / / c l a d d i n g i n d ex9 p hi c = asin ( n 2 / n 1 ) * 5 7 . 3 ;

10 NA = sqrt ( n1 ^ 2 - n 2 ^2 ) ;

11 p hi 0 = asin ( N A ) * 5 7 . 3 ;

12 disp ( p h i c , ’ C r i t i c a l a n lg e ’ )

13 disp ( N A , ’ n u m e ri c a l a p e r t u r e ’ )

14 disp ( p h i 0 , ’ a c ce pt a nc e a n ge l i n a i r ’ )

15 / / R e s u l t16 // C r i t i c a l a n lg e17 // 8 0 . 5 7 5 9 2 718 / / n u m e ri c a l a p e r t u r e

19 // 0 . 2 4 2 4 8 7 120 // a c c e p t a n ce a n ge l i n a i r21 // 1 4 . 0 3 4 4 1 2

Scilab code Exa 2.31 / / C a p ti o n : Pro gra m t o C a l c u l a t eNORMALIZED FREQUENCY ’V’ and Nu me ri ca l Ap er tu re

2 // Example2 . 33 / / P ag e 5 84 c l ea r a ll ;

5 close ;6 clc ;

7 a = 25 e -0 6;

8 L a m bd a = 1 30 0 e - 0 9 ;

9 V = 26 .6 ;

10 N u m e r ic a l _ Ap e r t u re = V * L a m b da / ( 2 * % p i * a )

11 disp (Numerical_Aperture , ” N u me ri ca l A p er tu r e i s ” ) ;

12 disp ( M = ( V ^2 ) /2 , ’ T o t a l number o f mod es M e n t e r i n gt h e f i b e r i s : ’ )

13 / / R e s u l t14 // Nu m er i ca l A pe r t ur e i s : 0 .2 20 14 31

15 // T ot al number o f modes M e n t e r i n g t he f i b e r i s :3 5 3 . 7 8

8



Scilab code Exa 2.41 / / C a p ti o n : Power f l o w i n t h e c o r e and

c l ad d i n g o f s te p−

i nd ex f i b e r2 / / E xa mp le 2 . 43 / / p ag e 6 24 clear ;

5 close ;

6 clc ;

7 V = [ 22 , 3 9] ;

8 M = V ^ 2/ 2;

9 P c l ad d _ P = ( 4 /3 ) * ( M . ^ ( - 0 .5 ) ) ;

10 P c or e _P = 1 - P c la d d_ P ;

11 disp (M , ’ T o t a l n um be r o f m od es ’ )

12 disp ( P c l a d d _ P * 1 0 0 , ’ P e r ce n t a ge o f p ower p r o p a g a t es i nt he c l a d d i ng ’ )

13 / / R e s u l t14 / / T o t a l number o f mod es15 // 2 4 2 . 7 6 0 . 516 // P er ce nt ag e o f power p r o p ag a te s i n t he c l ad d i ng17 // 8 . 5 7 0 9 9 1 3 4 . 8 3 4 9 1 8 2

Scilab code Exa 2.51 / / C ap ti on : Program t o c a l c u l a t e

F i be r B i r e f r i n g e n c e BETA f 2 // Example2 . 53 / / p ag e 6 54 c l ea r a ll ;

5 close ;

6 clc ;

7 L am b da = input ( ’ E nt er t h e w a ve l en g th o f O p t i c a lS i g n a l ’ ) ;

8 Lp = input ( ’ Be at Le ngt h ’ ) ;

9 B E T A _f _ F O RM U L A 1 = 2 * % pi / L p ;

10 disp (BETA _f_FORMULA1 , ”The f i b e r b i r e f r i e n g e n c e u si ng

f o rm u l a 1 ”) ;11 B E T A _f _ F O RM U L A 2 = L a m bd a / L p ;

12 disp (BETA _f_FORMULA2 , ”The f i b e r b i r e f r i e n g e n c e u si ngf o rm u l a 2 ”) ;

13 / / R e s u l t

9



14 // E n te r t he w av el en gt h o f O p t i ca l S i g n a l 1 30 0 e−09

15 / / B ea t L en gt h 8 e−

0216 // The f i b e r b i r e f r i e n g e n c e u si ng f or mu la 17 8 . 5 3 9 8 1 6

17 // The f i b e r b i r e f r i e n g e n c e u si ng f or mu la 20 . 0 0 0 0 1 6 2

10



Chapter 3

Third chapter

Scilab code Exa 3.1

1 / / C a p t i o n : P ro gr am t o F in d A t t e n u a t i o n i n dB/km2 // Example3 . 13 / / p ag e 9 14 clear ;

5 clc ;

6 z = [1 2]; // d i a t an c e s a re i n k i l o me t e r7 a l p h a _i n _ d B_ p e r _ km = 3 ;

8 r = ( a l p h a _ i n_ d B _ p er _ k m * z ) / 1 0;

9 P 0_ Pz = ( 10 ^ r ) ;10 for i = 1: length ( P 0 _ P z )

11 P z_ P0 ( i ) = 1 - (1 / P 0_ Pz ( i ) ) ;

12 end

13 disp ( P z _ P 0 * 1 0 0 , ’ O p ti c al s i g n a l power d e cr e as e d by i np e r c e n t a g e ’ )

14 //RESULT15 // O p t i ca l s i g n a l power d e c re a s ed by i n p e r ce n t ag e16 // 4 9 . 8 8 1 2 7 717 // 7 4 . 8 8 1 1 3 6

Scilab code Exa 3.21 / / C ap ti on : To C a l c u l a t e i n p u t ando u t p u t p ow er i n dBm

2 // Example3 . 2

11



3 / / p ag e 9 1

4 clear ;5 close ;

6 clc ;

7 P in = 2 00 e - 0 6; // power l au nc he d i n t o t he f i b e r8 a lp ha = 0 .4 ; / / a t t e n u a t i o n i n dB p e r KM9 z = 30; // o p t i c a l f i b e r l e ng t h 30 KM

10 P in _d Bm = 1 0* log10 ( P i n / 1 e - 0 3 ) ;

11 P o ut _d B m = 1 0* log10 ( P i n / 1 e - 0 3 ) - a l p h a * z ;

12 P o ut = 1 0 ^( P o u t_ d B m / 1 0)

13 disp (Pin _dBm , ’ Pin dBm ’ )

14 disp (Po ut_dBm , ’ Pout dBm ’ )

15 disp ( P o u t * 1 e - 0 3 , ’ O u tp ut p ow er i n w a t ts ’ )16 / / R e s u l t17 //P in dBm = − 6 . 9 8 9 718 //Pout dBm = − 1 8 . 9 8 9 719 // Output power i n w at ts = 0 . 00 0 0 12 6

Scilab code Exa 3.31 // C a pt io n : R a yl e ig h s c a t t e r i n g l o s s2 // Example3 . 33 / / p a g e 9 7

4 clear ;5 close ;

6 clc ;

7 a l ph a _0 = 1 .6 4; / / a t t e n u a t i o n a t La mb da 0 i n dB /KM8 L a mb da _ 0 = 8 50 e - 0 9; / / w a v el e n g th 8 50 n an om et er9 L am b da = 1 31 0 e - 09 ; / / w a v e l e n g t h 1 3 5 0 n a no m et e r

10 a l p h a_ L a m bd a = a l p ha _ 0 * ( ( L a m b da _ 0 / L a m bd a ) ^ 4 ) ;

11 disp (alpha_Lambda , ’ R ay le ig h s c a t t e r i n g l o s s a lp ha (Lambda) = ’ )

12 / / R e s u l t13 / / R a y le i g h s c a t t e r i n g l o s s a l ph a ( Lambda ) = 0 . 2 9 0 6 92 9

Scilab code Exa 3.41 / / C a p ti o n : Pro gra m t o c a l c u l a t ep e r ce n t i n d e c r e a s e o f number o f modes

12



2 / / E xa mp le 3 . 4

3 / / p ag e 9 94 clear ;

5 clc ;

6 a lp ha = 2; // g ra de d i n de x p r o f i l e7 n2 = 1. 5; / / c l a d d i n g8 L am da = 1 .3 e - 0 6; // w av e l e ng t h9 R = 0. 01 ; // bend r a d i u s o f c u r va t u re

10 a = 25 e -0 6; // c or e r a di u s11 d el ta = 0 .0 1; // cor e−c l a d d i ng i nd ex p r o f i l e12 k = 4 .8 3 e0 6; / / p r o p a g a t i o n c o n s t a n t13 disp (k , ’ k = ’ )

14 p ar t1 = ( 2* a / R )+ floor ( ( 3 / ( 2 * n 2 * k * R ) ) ^ ( 2 / 3 ) ) ;15 p a rt 2 = ( a l p ha + 2 ) / ( 2 * a l p ha * d e l t a ) ;

16 N e f f_ N i nf = 1 - p a r t1 * p a r t 2 ;

17 disp ( ’ n umber o f modes d e c r e a s e d by ’ )

18 disp ( ’ P er ce n t i n g ra ded−i nd ex f i b e r ’ , N e f f _ N i n f * 1 0 0 )

19 //RESULTS20 // number o f modes d e c re a s ed by 50 P er ce nt i n g ra ded

−i nd ex f i b e r

Scilab code Exa 3.5

1 // C a pt io n : C a l c u l a t i o n o f p u l s e b ro a de ni n g2 // Example3 . 53 / / p ag e 1 034 clear ;

5 clc ;

6 close ;

7 C = 3 e 0 8 ; // f r e e s pa ce v e l o c i t y i n me t r e / s e c8 n1 = 1 .4 8; // c o re r e f r a c t i v e i nd ex9 n 2 = 1 .4 65 ; // c l ad d i n g r e f r a c t i v e i nd ex

10 d el ta = 0 .0 1; // i nd ex d i f f e r e n c e

11 L = 10 ^3 ; / / f i b e r l e n g t h 1 0KM12 d e l ta T = ( L * ( n 1 ^ 2) / ( C * n 2 ) ) * d e lt a ;

13 disp ( ( d e l t a T / L ) * 1 0 ^ 1 2 , ’ p u l s e b r o a d e n i ng i n n s /KM ’ )

14 / / R e s u l t15 / / p u l s e b r o ad e n in g i n n s /KM = 4 9 . 8 3 8 45 3

13



Scilab code Exa 3.6

1 // C a p ti on : C a l c u l a t i o n o f b an dw id th d i s t a n c e2 // Example3 . 63 / / p ag e 1 044 clear ;

5 clc ;

6 close ;

7 n1 = 1 .4 8; // c o re r e f r a c t i v e i nd ex8 n 2 = 1 .4 65 ; // c l a d d i n i g r e f r a c t i v e i nd ex9 d el ta = 0 .0 1; // i nd ex d i f f e r e n c e

10 C = 3 *( 1 0^ 8 ) ; // f r e e s pa ce v e l c o t i y11 B L = ( n 2 /( n 1 ^ 2) ) * ( C / de lt a ) ;

12 disp ( B L , ’ B an dwidth d i s t a n c e i n bPS−M’ )

13 disp ( B L / 1 0 ^ 9 , ’ B an dw id th d i s t a n c e i n MbPS−KM’ )

14 / / R e s u l t15 / / Ba nd wi dt h d i s t a n c e i n bPS−M16 // 2 . 0 0 6D+1017 / / B an dw id th d i s t a n c e i n MbPS−KM18 // 2 0 . 0 6 4 8 2 8

Scilab code Exa 3.71 / / C a p t i o n : P ro gr am t o F in d o u t t h eM a t er i a l D i s p e r s i o n

2 // Example3 . 73 / / p a g e 1 0 74 clear ;

5 clc ;

6 L am da = 8 00 e - 0 9; / / W a ve le n gt h i n m e te r7 s i g m a_ L a m da _ L E D = 4 0 e - 09 ; // s p e c t r a l w id th i n m et er s8 p u l s e_ s p r ea d = 4 . 4 e - 12 ; / / p u l s e s p r ea d i n s e c / m et er

9 m a t _ di s p e rs i o n = p u l se _ s p re a d / s i g m a _ L a md a _ L ED10 disp (mat_d ispersion , ’ m a t er i a l d i s p e r s i o n i n s e c on ds /s q u a r e m e te r ’ )

11 / / R e s u l t12 // m a t e r i a l d i s p e r s i o n i n s e co n ds / s q ua r e m et er

14



0 . 0 0 0 1 1

Scilab code Exa 3.81 / / C a p t i o n : P ro gr am t o F in d o u tWa veg ui de D i s p e r s i o n


5 clc ;

6 n2 = 1 .4 8; // i n de x o f c l a d d i ng7 d el ta = 0 . 00 2; // i nd ex d i f f e r e n c e8 L am da = 1 32 0 e - 09 ; / / W av el en gt h i n m e t er s9 V _ dV b_ d V = 0 .2 6; // The v al ue i n s q u ar e b r ac k e t s f o r

v = 2 . 410 C = 3 e0 8 ;// E n t e r t h e v e l o c i t y o f l i g h t i n f r e e s p ac e11 D w g _L a m da = - (( ( n 2 * d el t a ) / C ) * (1 / L a m da ) ) * V _ d V b _ dV

12 disp ( D w g _ L a m d a * 1 e 0 6 , ’ The w a ve gu id e d i s p e r s i o n i n p s /nm.km’ ) ;

13 //RESULTS14 // The wa ve gu id e d i s p e r s i o n i n p s /nm . km = −

1 . 9 4 3 4 3 4 3

15



Chapter 4

Fourth chapter

Scilab code Exa 4.11 / / C a p t i o n : P ro gr am t o f i n d i n t r i n s i cc a r r i e r c o nc e n t r a t i o n


5 close ;

6 clc ;

7 m = 9 .1 1 e -3 1; // E l e c tr o n r e s t mass i n kg8 m e = 0 .0 68 * m; // E f f e c t i v e e l e c t r o n mass kg9 m h = 0 .5 6* m ; // E f f e c t i v e h o l e mass i n kg

10 E g = 1 . 42 * 1. 6 02 1 8 e - 19 ; //band−gap e ne rg y i n v o l t s11 k B = 1 . 38 0 54 e - 2 3; / / B ol tz ma ’ s c o n s t a n t12 T = 3 0 0 ; // room t e m pe r a tu r e i n k e l v i n13 h = 6 .6 25 6 e - 34 ; / / P l an c k ’ s c o n s t a n t14 K = 2 * (( 2 * % p i * k B * T /( h ^ 2 ) ) ^ 1 . 5) * ( ( m e * m h ) ^ 0 .7 5 ) ; //

c h a r a c t e r i s t i c c on st an t o f m a t e r i a l15 n i = K * %e ^ ( - Eg / ( 2* k B * T )) ;

16 disp ( n i , ’ i n t r i n s i c c a r r i e r c o n c e n t r a t i o n i n c u b i cmeter ’ )

17 / / R e s u l t18 / / i n t r i n s i c c a r r i e r c o n c e n t r a t i o n i n c ub e m et er

2.551D+12

16



Scilab code Exa 4.3

1 / / C a p t i o n : F i n d i n g E neg y g ap a nd W a ve le ng t h2 // Example4 . 33 / / p a g e 1 4 64 clear ;

5 close ;

6 clc ;

7 x = 0. 07 ; / / c o m p o s i t i o n a l p a ra m et er o f GaAlAs8 E g = 1 . 4 2 4+ 1 . 2 66 * x + 0 . 2 6 6* x ^ 2 ;

9 L am da = 1 . 24 0/ E g ;

10 disp ( E g , ’ Band E ne rg y g ap i n e v ’ )

11 disp ( L a m d a , ’ W a ve le ng t h i n m i c r o m e t e r s ’ )

12 / / R e s u l t13 // Band Energy gap i n ev 1 . 5 1 3 9 23 414 / / W av el en gt h i n m i cr o m e te r s 0 . 8 1 9 0 63 9

Scilab code Exa 4.4

1 / / C a p t i o n : F i n d i n g E neg y g ap a nd W a ve le ng t h2 // Example4 . 43 / / p a g e 1 4 64 clear ;

5 close ;

6 clc ;

7 y = 0. 57 ; / / c o m p o s i t i o n a l p a ra m et er o f InGaAsP8 E g = 1 . 35 - 0 . 7 2 * y + 0 . 12 * ( y ^ 2 ) ;

9 L am da = 1 . 24 0/ E g ;

10 disp ( E g , ’ Band E ne rg y g ap i n e v ’ )

11 disp ( L a m d a , ’ W a ve le ng t h i n m i c r o m e t e r s ’ )

12 / / R e s u l t13 // Band E nerg y g ap i n ev 0 . 9 78 5 8 814 / / W av el en gt h i n m i cr o m e te r s 1 . 2 6 7 1 31 8

Scilab code Exa 4.5

1 // C a p ti on : To f i n d o ut t h e I n t e r n a l QuantumE f f i c i e n c y and I n t e r n a l Power l e v e l o f LED s o u r ce

2 // Example4 . 5

17



3 / / p a g e 1 4 9

4 clear ;5 clc ;

6 t uo _r = 3 0e - 0 9; // r a d i a t i v e r e co m b in a ti o n i n s e co n d s7 t u o _n r = 1 00 e - 0 9 ; //non−r a d i a t i v e r ec om bi na t i on i n

s e c o n d s8 E t t a _i n t e rn a l = 1 / (1 + ( t u o _r / t u o _ n r ) ) ; // i n t e r n a l

quantum e f f i c i e n c y9 h = 6 .6 25 6 e - 34 ; / / P la nk ’ s c o n s t a n t

10 C = 3 e 0 8 ; / / v e l o c i t y i n m/ s e c11 q = 1 .6 02 e - 19 ; // e l e c t r o n c ha r ge i n c ou lo mb s12 I = 40 e -0 3; / / d r i v e c u r r e n t i n Amps

13 L am da = 1 31 0 e - 09 ; / / p ea k w a v e l e n g t h o f InGaAsP LED14 P i n te r n al = ( E t t a _ i nt e r n al * (( h * C ) / q ) ) * ( I / L am d a ) ; //

i n t e r n a l power l e v e l15 disp (Pinternal , ’THE INTERNAL POWER GENRATED WITH IN

LED SOURCE IN WATTS I S ’ ) ;

16 disp (Etta_in ternal , ’ The i n t e r n a l Quantum e f f i c i e n c yf o r t h e g iv en r a d i a t i v e and n on−r a d i a t i v er e co m b in a ti o n t im e i s ’ ) ;

17 disp ( E t t a _ i n t e r n a l * 1 0 0 , ’ I n t e r n a l Quantum E f f i c i e n c yi n P e r ce n t ag e ’ ) ;

18//RESULT19 //THE INTERNAL POWER GENRATED WITH IN LED SOURCE IN

WATTS I S20 / / 0 . 0 2 9 1 4 2 721 // The i n t e r n a l Quantum e f f i c i e n c y f o r t he g i v en

r a d i a t i v e and non−r a d i a t i v e r ec om bi na t i o n t im e i s0 . 7 6 9 2 3 0 8

22 / / I n t e r n a l Quantum E f f i c i e n c y i n P e r ce n t ag e23 / / 7 6 . 9 2 3 07 7

Scilab code Exa 4.61 / / C a p t i o n : E x t e r n a l QuantumE f f i c i e n c y i n p e r ce nt a g e

2 / / E xa mp le 4 . 63 / / p a g e 1 5 14 clear ;

18



5 close ;

6 clc ;7 n = 3 . 5 ; // r e f r a c t i v e i nd ex o f an LED8 E t t a _E x t e rn a l = 1 /( n * ( n + 1 ) ^ 2) ;

9 disp ( E t t a _ E x t e r n a l * 1 0 0 , ’ E x t e r na l E f f i c i e n c y i np e r c e n t a g e ’ )

10 / / R e s u l t11 // E x te rn al E f f i c i e n c y i n p e r ce nt ag e 1 .4 10 93 47

Scilab code Exa 4.7

1 / / C a pt i on : Pr og ram t o f i n d L a s i n g T h r es h o l d g a i n


5 clc ;

6 L = 5 00 e - 06 ; // L a se r d i od e l e n g t h i n m et er s7 R1 = 0. 32 / / r e f l e c t i o n c o e f f i c i e n t v a l u e o f o ne en d ;8 R2 = 0. 32 / / r e f l e c t i o n c o e f f i c i e n t v a l u e o f a n o t h e r

end ;9 a l p ha _ b ar = 1 0/ 1 e - 0 2 ; // a b s o r p t i o n c o e f f i c i e n t ;

10 a l p ha _ e nd = ( 1 /( 2 * L ) ) * log ( 1 / ( R 1 * R 2 ) ) ; // m i rr o r l o s si n t h e l a s i n g c a v i t y

11 a l p h a_ t h r es h o l d = a l p ha _ b ar + a l p ha _ e nd ; // t o t a l l o s s12 disp (alph a_threshold , ” The T h r es h o l d G ai n p e r m et re ” )

13 a l p h a _t h r e sh o l d _ cm = a l p h a _t h r e s ho l d / 1 0 0

14 disp ( a l p h a _ t hr e s h o ld _ c m , ” The T h r es h o l d Ga in p e rc e n t i m e t r e ” ) ;

15 / / R e s u l t16 / / The T h r es h o l d G ai n p e r m et re 3 2 7 8 . 8 6 8 617 / /The T h re s ho l d Gain p e r c e n t i m e t r e 3 2 . 7 8 8 68 6

Scilab code Exa 4.81 / / C a p t i o n : P ro gr am TO C a l c u l a t eF r e qu e n cy S p a c i n g & W a v el e ng t h S p a c i n g


19



5 clc ;

6 L am da = 8 50 e - 9 / / E m i s s i o n w a v e l e n g t h o f LASER d i o d e7 n = 3.7 / / r e f r a c t i v e i n d ex o f LASER d i o d e8 L = 500 e -6 / / l e n g t h o f LASER d i o d e9 C = 3 e 0 8 // v e l o c i t y o f L ig ht i n f r e e s pa ce

10 d e l t a_ f r e qu e n c y = C / ( ( 2* L ) * n ) ;

11 d e l ta _ L a md a = ( L a m da ^ 2 ) / ( ( 2 * L ) * n );

12 H a lf _ po w er = 2 e - 09 ; / / h a l f p ower p o i n t 3 n an om et er13 s ig ma = sqrt ( - ( H a l f _ p o w e r ^ 2 ) / ( 2 * log ( 0 . 5 ) ) ) ;

14 disp (delt a_frequency , ’ E nt er t he f r e qu e n cy s p a c in g i nH e r t z ’ ) ;

15 disp (delta_Lamda , ’ E nt er t he w ae le ng th s p a ci n g i n

m e t r e s ’ ) ;16 disp ( s i g m a , ’ s p e c t r a l w i d th o f t he g ai n ’ ) ;

17 //RESULT18 // E n te r t he f r e qu e n cy s p a c in g i n H er tz19 // 8 . 10 8D+1020 // E n te r t he w ae le ng th s p a c in g i n m et re s21 // 1 .9 53D−1022 // s p e c t r a l w i d th o f t he g ai n23 // 1 . 6 9 9D−09

Scilab code Exa 4.91 / / C a p ti o n : C a l c u a l t i o n o f number o f h a l f −w a v el e n gt h s and w a ve l en g th s p a c i n g b et we enl a s i n g modes


5 clc ;

6 close ;

7 L am b da = 9 00 e - 0 9; // w av el en gt h o f l i g t h e mi tt ed byl a s e r d io da

8 L = 3 00 e - 06 ; // l en gt h o f l a s e r c h ip9 n = 4 . 3 ; // r e f r a c t i v e i nd ex o f t h e l a s e r m a te r i a l

10 m = 2 * L* n / L am b da ; / / number o f h a l f −w a v e l e n g t h s11 d e l t a_ L a m bd a = ( L a m b da ^ 2 ) / ( 2 * L * n ) ; // w av e l e ng t h

s p a c i n g

20



12 disp (m , ’ n umber o f h a l f −w a v el e n g th s s p an n in g t h e

r e g i o n b et wee n m i rr o r s u r f a c e s ’ )13 disp (delta_Lambda , ’ s p a ci n g b et wee n l a s i n g modes i s ’ )

14 / / R e s u l t15 / / number o f h a l f −w a ve l en g th s s pa nn in g t he r e g i o n

bet w ee n m ir ro r s u r f a c e s 2 86 6. 66 6716 // s p ac i n g bet w e en l a s i n g modes i s 3 . 14 0D−10

21



Chapter 5

Fifth chapter

Scilab code Exa 5.11 // C a pt io n : C a l c u l a t i o n o f L a t e r a lp o we r d i s t r i b u t i o n c o e f f i c i e n t


5 clc ;

6 close ;

7 phi = 0; // l a t e r a l c o o r d i n a te8 H a lf _ po w er = 1 0; / / h a l f p ow er beam w i dt h9 t et a = H a lf _ po w er / 2 ;

10 t e ta _r a d = t et a / 5 7. 3;

11 L = log ( 0 . 5 ) / log ( cos ( t e t a _ r a d ) ) ;

12 disp (L , ’ L a t e r a l p ow er d i s t r i b u t i o n c o e f f i c i e n t L= ’ )

13 / / R e s u l t14 / / L a t e r a l p ow er d i s t r i b u t i o n c o e f f i c i e n t L =

1 8 1 . 8 3 3 0 3

Scilab code Exa 5.21 / / C a p ti o n : Pro gra m t o C a l c u a l t e

O p t i c a l Power E mi tt ed f ro m t h e L i g h t s o u r c e andO p t i ca l power c ou p le d t o s te p−i nd ex f i b e r


22



5 close ;

6 clc ;7 r s = 35 e -0 6; // t he s o u r ce r a d i u s i n m et er8 a = 25 e -0 6; // t h e c or e r a d i i o f s t e p−i nd ex f i b e r

me t e r9 NA = 0 .2 0; // t he n u me r ic a l a p e r tu r e v a lu e

10 B o = 1 50 e 04 ; // r a d i a n c e i n W/ s q u a r e m et er . s r11 P s = ( ( %p i ^ 2) * ( r s ^2 ) ) * Bo ; / / po wer e m i tt e d by t h e

s o u r c e12 if ( r s <= a ) then

13 P L ED _ st e p = P s *( N A ^ 2) ;

14 elseif ( r s > a ) then

15 P L E D_ s t ep = ( (( a / r s ) ^ 2 ) * Ps ) * ( N A ^ 2 ) ;16 end

17 disp ( P s , ’ O p t i c a l p ower e m i tt e d by LED l i g h t s o u r c eP s = ’ )

18 disp (PLED_step , ’ O p t i c a l Power c o u pl e d i n t o s t e pi n d ex f i b e r i n Watts PLED step = ’ ) ;

19 //RESULT20 / / O p t i c a l p ower e m i tt e d by LED l i g h t s o u r c e Ps =

0 . 0 1 8 1 3 5 421 // O p ti c al Power c ou pl ed i n t o s t ep i nd ex f i b e r i n

Watts P LED step = 0 . 0 0 0 3 7 01

Scilab code Exa 5.31 / / C ap ti on : F r e s n e l r e f l e c t i o n , p ow erc o up l ed and power l o s s


5 clc ;

6 close ;

7 n 1 = 3. 6; // r e f r a c t i v e i nd ex o f o p t i c a l s o u r c e

8 n = 1. 48 ; // r e f r a c t i v e i nd ex o f s i l i c a f i b e r9 R = ( ( n1 - n ) / ( n1 + n ) ) ^2 ;

10 L = -10* log10 ( 1 - R ) ;

11 disp (L , ’ Power l o s s i n dB L = ’ )

12 / / R e s u l t

23



13 // Power l o s s i n dB L = 0 . 8 31 0 3 22

Scilab code Exa 5.41 / / C a p t i o n : P ow er c o u p l e d b e t w ee n t wog ra de d i nd ex f i b e r s


5 clc ;

6 close ;

7 a = 1e - 0 6; // c o re r a d i i i n m et er s8 d = 0 .3 *a ; // a x i a l o f f s e t9 P T_ P = ( 2/ % p i ) *( acos ( d / ( 2 * a ) ) - ( 1 - ( d / ( 2 * a ) ) ^ 2 ) ^ 0 . 5 * ( d

/ ( 6 * a ) ) * ( 5 - 0 . 5 * ( d / a ) ^ 2 ) ) ;

10 P T_ P_ dB = 1 0* log10 ( P T _ P )

11 disp (PT_ P_dB , ’ O p t i c a l p ower c o u pl e d f ro m f i r s t f i b e ri n t o s ec o nd f i b e r i n dB i s = ’ )

12 / / R e s u l t13 / / O p t i c a l p ower c o u pl e d fr om f i r s t f i b e r i n t o s e co n d

f i b e r i n dB i s = − 1 . 2 5 9 7 8 1 3

Scilab code Exa 5.51 / / C ap ti on : L o ss b et we en s i n g l e modef i b e r s due t o L a t e r a l m is al ig nm en t


5 clc ;

6 close ;

7 V = 2 .4 05 ; / / n o r m a l i z e d f r e q u e n c y8 n 1 = 1 .4 7; // c o re r e f r a c t i v e i nd ex9 n 2 = 1 .4 65 ; // c l ad d i ng r e f r a c t i v e i nd ex

10 a = ( 9/ 2) * 1 0^ - 0 6; // c o re r a d i i i n m et er s11 d = 1e - 06 ; // l a t e r a l o f f s e t i n m e t e r s12 W = a * ( 0 . 6 5 +1 . 6 1 9* V ^ ( - 1 .5 ) + 2 . 8 79 * V ^ - 6 ) ;

13 L sm = -1 0* log10 ( exp ( - ( d / W ) ^ 2 ) ) ;

14 disp (W , ’mode− f i e l d d i a m e t e r i n m e t er s W = ’ ) ;

24



15 disp ( L s m , ’ L os s bet w e en s i n g l e mode o p t i c a l f i b e r s

due t o l a t e r a l o f f s e t Lsm = ’ )16 / / R e s u l t17 //mode− f i e l d d i a m e t e r i n m e te r s W = 0 . 0 0 0 0 04 918 // L os s b et w ee n s i n g l e mode o p t i c a l f i b e r s due t o

l a t e r a l o f f s e t Lsm = 0 . 17 75 79 7

Scilab code Exa 5.61 / / C a p ti o n : L o s s b et we en s i n g l e modef i b e r s due t o a n gu l a r m is al ig nm en t


5 clc ;

6 close ;

7 clear ;

8 clc ;

9 close ;

10 V = 2 .4 05 ; / / n o r m a l i z e d f r e q u e n c y11 n 1 = 1 .4 7; // c o re r e f r a c t i v e i nd ex12 n 2 = 1 .4 65 ; // c l ad d i ng r e f r a c t i v e i nd ex13 a = ( 9/ 2) * 1 0^ - 0 6; // c o re r a d i i i n m et er s

14 d = 1e - 06 ; // l a t e r a l o f f s e t i n m e t e r s15 W = a * ( 0 . 6 5 +1 . 6 1 9* V ^ ( - 1 .5 ) + 2 . 8 79 * V ^ - 6 ) ; //mode− f i e l d

d i a m e t e r16 te ta = 1; / / i n d e g r e e s17 t et a = 1 / 57 .3 ; / / i n r a d a i a n s18 L am b da = 1 30 0 e - 09 ; / / w a v el e n g th i n m e t er s19 L s m_ a ng = - 10 * log10 ( exp ( - ( % p i * n 2 * W * t e t a / L a m b d a ) ^ 2 ) ) ;

20 disp (Lsm _ang , ’ L os s b et we en s i n g l e mode f i b e r s due t oa n g u l a r m i s al i g nm e n t Lsm ang = ’ )

21 / / R e s u l t22 // L os s b et w ee n s i n g l e mode f i b e r s due t o a n gu l ar

m i s a l i g n m en t L sm a ng = 0 . 4 0 5 4 6 5 8

25



Chapter 6

Sixth chapter

Scilab code Exa 6.1

1 // Capt ion : Cut−o f f w av el en gt h o f p h ot o di o de2 // Example6 . 13 / / p a g e 2 2 44 clear ;

5 clc ;

6 close ;

7 h = 6 . 62 5* ( 10 ^ - 3 4) ; / / p l a n k s c o n s t a n t8 C = 3 *( 10 ^8 ) ; // f r e e s pa ce v e l o c i t y9 E g = 1 .4 3 *1 . 6* ( 10 ^ - 1 9 ) ; / / j o u l e s

10 L a mb d aC = h * C / Eg ;

11 disp (Lam bdaC , ’Cut−o f f Wa vel eng th o f p h ot o di o de i nm e t e r s = ’ )

12 / / R e s u l t13 //Cut−o f f W av el en gt h o f p h o to d i o de i n m e te r s=

0 . 0 0 0 0 0 0 9

Scilab code Exa 6.2

1 // C a pt io n : C a l c u l a t i o n o f Quantum e f f i c i e n c y2 // Example6 . 23 / / p ag e 2 264 clear ;

5 clc ;

26



11 e tt a = 0 .9 ; // quantum e f f i c i e n c y 9 0%

12 h = 6 .6 2 5* 10 ^ - 3 4; / / p l a n k s c o n s t a n t13 R = ( e tt a * q) / ( h* v ) ; / / R e s p o n s i v i t y14 disp (R , ’ R e s p o n s i v i t y o f p h o to d i o de a t 1 33 0nm i n A/W

R = ’ )

15 Eg = 0 .7 3; // e ne rg y gap i n e l e c t r o n v o l t s16 L a mb d aC = 1 .2 4/ E g ; / / c u t−o f f w av el en gt h i n m et er s17 disp (Lam bdaC , ’ cu t−o f f w av el en gt h i n m et er s = ’ )

18 / / R e s u l t19 / / R e s p o n s i v i t y o f p h o t o d i o d e a t 1 3 30nm i n A/W R =

0 . 9 4 1 8 8 6 820 / / c u t−o f f w av el en gt h i n m et er s = 1 .6 9 8 63 0 1

Scilab code Exa 6.51 / / C a p ti o n : To f i n d p r im a ryp h ot o cu r r e n t and m u l t i p l i c a t i o n f a c t o r


5 clc ;

6 close ;

7 e tt a = 0 .6 5; / / quantum e f f i c i e n c y o f s i l i c o n

q a v a l a n c he p h o t o d i o d e8 C = 3 *( 10 ^8 ) ; // f r e e s pa ce v e l o c i t y i n m/ s9 L am b da = 9 00 e - 0 9; / / w a v el e n g th i n m e t er s

10 q = 1 .6 *( 10 ^ - 1 9) ; / / c h a r g e i n c ou l om b s11 h = 6 . 62 5* ( 10 ^ - 3 4) ; / / p l a n k s c o n s t a n t12 v = C / La mb da ; // f r e q u n e cy i n Hz13 P in = 0 .5 *1 0^ - 0 6 ; // o p t i c a l p ower14 I p = ( ( et ta * q ) /( h * v )) * P in ;

15 I m = 1 0* (1 0^ - 0 6 ) ; / / m u l t i p l i e d p h o t o c u r r en t16 M = I m / I p ; // m u l t i p l i c a t i o n f a c t o r17 disp ( I p * 1 0 ^ 6 , ’ P r im a ry p h o t o c u r r e n t i n uAmps I p= ’ )

18 disp ( ceil ( M ) , ’ Pr im ary p h o to c u rr e n t i s m u l t i p l i e d bya f a c t o r o f M = ’ )

19 / / R e s u l t20 // P ri ma ry p h o t o cu r r en t i n uAmps I p = 0 . 23 5 4 71 7

28



21 // P ri mar y p h ot o cu r r e nt i s m u l t i p l i e d by a f a c t o r o f

M = 4 3 .

Scilab code Exa 6.61 // Capt ion :Mean−s qu ar e s ho t n o i s ec u r r e n t , Mean−s q u a re d ar k c u r r e n t and Mean−S q u a r e

t he rm al n o i s e c u r r e nt2 // Example6 . 63 / / p ag e 2 344 clear ;

5 clc ;

6 close ;

7 L am b da = 1 33 0 e - 09 ; / / w a v el e n g th i n m e t er s8 I D = 4 e -0 9; / / p h o t o d i o d e c u r r e n t9 e tt a = 0 .9 0; // quantum e f i c i e n c y

10 RL = 1 00 0; / / Load r e s i s t a n c e 1 00 0 ohms11 P in = 3 00 e - 0 9; // i n c i d e n t o p t i c a l power i s 300 nano

w a t t s12 B e = 2 0* (1 0^ 6) ; / / r e c e i v e r b an dw id th13 q = 1 .6 *( 10 ^ - 1 9) ; / / c h a r g e i n c ou l om bs14 h = 6 .6 2 5* 10 ^ - 3 4; / / p l a n k s c o n s t a n t15 v = ( 3 * 10 ^ 8 ) / L a m bd a ; / / f r e q u e n c y i n Hz16 I p = ( e tt a * q * Pi n ) /( h * v );

// p r i ma ry p h o t o c u r re n t17 I sh ot = 2 * q* I p * Be ; / / s h o t−n o i s e c u r r e nt18 I sh ot = sqrt ( I s h o t ) ;

19 I DB = 2 * q* I D * Be ; // d a rk c u r r e n t20 IDB = sqrt ( I D B ) ;

21 T = 2 8 3 ; // room t e m pe r a tu r e i n k e l v i n22 K B = 1 .3 8 *1 0^ - 2 3 ; / / b o lt zm a nn ’ s c o n s t a n t23 RL = 1 00 0; // l oa d r e s i s t a n c e24 I T = ( 4* K B * T) * Be / R L ;/ / Therma l n o i s e c u r r e n t25 IT = sqrt ( I T ) ;

26 disp ( I p * 1 0 ^ 6 , ’ p ri ma ry p h o t o c u r re n t i n uA IP = ’ )

27 disp ( I s h o t * 1 0 ^ 9 , ’mean−

s qu ar e s ho t n o i se c u r r e n t f o ra p in p ho to di od e i n nA I s h o t = ’ )

28 disp ( I D B * 1 0 ^ 9 , ’mean−s q u a r e d ar k c u r r e n t i n nA IDB= ’ )

29 disp ( I T * 1 0 ^ 9 , ’mean−s q u ar e t he rm al n o i s e c u r r e nt f o rt h e r e c e i v e r i n nA IT =’ )

29



30 / / R e s u l t

31 // p r im ar y p h o to c u rr e n t i n uA IP = 0 . 28 9 0 86 832 //mean−s qu ar e s ho t n o i se c u r r e n t f o r a p i np ho to di od e i n nA I s h o t = 1 . 3 60 2 04 2

33 //mean−s q ua r e d ar k c u r r en t i n nA IDB = 0 . 1 634 //mean−s qu ar e t he r ma l n o i se c u r r e n t f o r t he r e c e i v e r

i n n A I T = 1 7 . 6 7 5 7 4 6

Scilab code Exa 6.7

1 // C a p ti on : c i r c u i t b an dw id th o f a p h o to d i od e2 // Example6 . 73 / / p ag e 2 394 clear ;

5 clc ;

6 close ;

7 C P = 3 *1 0^ - 1 2; // p ho to di od e c a p ac i t an c e i s 3 p i cof a r a d

8 C A = 4 *1 0^ - 1 2; // a m p l i f i e r c a pc i ta n c e i s 4 p i c o f a r ad9 CT = CP + CA ; // t o t a l c a p a c i t a nc e

10 R T1 = 1 00 0; // p h ot o di o de l o ad r e s i s t a n c e11 B C1 = 1 /( 2* % p i * RT 1 * CT ) ; // c i r c u i t b an dw id th

12 RT2 = 50; // p h ot o di o de l o ad r e s i s t a n c e13 B C2 = 1 /( 2* % p i * RT 2 * CT ) ; / / c i r c u i t b an dw id th14 disp ( B C 1 , ’ C i r c u i t b an dw id th f o r 1 k i l o Ohm p h o to d i od e

r e s i s t a n c e BC1 = ’ )

15 disp ( B C 2 , ’ C i r c u i t b an dw id th f o r 50 ohm p h o to d i o der e s i s t a n c e BC2 = ’ )

16 / / R e s u l t17 / / C i r c u i t b an dw id th f o r 1 k i l o Ohm p h o t o d i o d e

r e s i s t a n c e BC1 = 2 2 7 36 4 2 0.18 // C i r c u i t b and wi dth f o r 50 ohm p h ot o di o de r e s i s t a n c e

BC2 = 4 . 5 4 7 D+08

30



Chapter 7

Seventh chapter

Scilab code Exa 7.1

1 // C a p ti on : To f i n d optimum d e c i s i o n t h r e s h o l d2 // Example7 . 13 / / P ag e 2 5 84 clear ;

5 clc ;

6 close ;

7 bon = 1;

8 b of f = 0;

9 s ig ma _o n = 1;10 s i gm a _o f f = 1 ;

11 Q = ( b on - b o f f ) / ( s i gm a _ on + s i g ma _ o ff )

12 V th = b on - Q * s i g ma _ on

13 disp (Q , ’Q p a r a me te r v a l u e = ’ )

14 disp ( V t h , ’ o ptimum d e c i s i o n t h r e s h o l d Vth = ’ )

15 / / R e s u l t16 / /Q p a ra m et er v a l u e = 0 . 517 / /optimum d e c i s i o n t h r e s h o l d Vth = 0 . 5

Scilab code Exa 7.2

1 // C a pt io n : To f i n d o ut s i g n a l−to−n o i s e r a t i o andp r o b a b i l i t y o f e r r o r f o r g iv en ’Q’

2 // Example7 . 2

31



Figure 7.1: Figure for Example7.3

3 / / P ag e 2 5 84 clear ;

5 clc ;

6 close ;

7 Q = 6;

8 P e = ( 1/ 2) * (1 - erf ( Q / sqrt ( 2 ) ) ) ;

9 S _N _d B = 1 0* log10 ( 2 * Q ) ;

10 disp ( P e , ’ P r o b a b i l i t y o f e r r o r Pe (Q) = ’ )

11 disp (S_N_dB , ’ S i g n a l−

to−

n o i s e r a t i o i n dB S/N = ’ )12 / / R e s u l t13 // P r o b a b i l i t y o f e r r o r Pe (Q) = 9 . 8 6 6D−1014 / / S i g n a l −to−n o i s e r a t i o i n dB S /N = 1 0 . 79 18 12

32



Scilab code Exa 7.3

1 / / C a pt i on : P l o t t i n g B it−

E r r o r−

Rate v e r s u s Q f a c t o r2 // Example7 . 33 / / p ag e 2 594 clear ;

5 clc ;

6 close ;

7 Q = 0 :0 .0 1: 8;

8 P e = ( 1/ 2) * (1 - erf ( Q . / sqrt ( 2 ) ) ) ;

9 a = gca () ;

10 a . d a t a _ bo u n d s = [0 , 1 e - 1 6 ; 8 , 0 . 5] ;

11 plot ( Q , P e , ’ r ’ )

12 x l a b e l ( ’Q ’ )13 y l a b e l ( ’ Pe ’ )

14 t i t l e ( ’BER( Pe ) v e r s u s t h e f a c t o r Q ’ )

15 disp ( P e ( 1 ) , ’ P r o b a b i l i t y o f e r r o r a t Q =0 ’ )

16 disp ( P e ( 1 0 1 ) , ’ P r o b a b i l i t y o f e r r o r a t Q =1 ’ )






22 disp ( P e ( 7 0 1 ) ,’ P r o b a b i l i t y o f e r r o r a t Q =7 ’

)


24 / / R e s u l t25 // P r o b a b i l i t y o f e r r o r a t Q =026 // 0 . 527 // P r o b a b i l i t y o f e r r o r a t Q =128 // 0 . 1 5 8 6 5 5 329 // P r o b a b i l i t y o f e r r o r a t Q =230 // 0 . 0 2 2 7 5 0 131 // P r o b a b i l i t y o f e r r o r a t Q =332 // 0 . 0 0 1 3 4 9 9

33 // P r o b a b i l i t y o f e r r o r a t Q =434 // 0 . 0 0 0 0 3 1 735 // P r o b a b i l i t y o f e r r o r a t Q =536 // 0 . 0 0 0 0 0 0 337 // P r o b a b i l i t y o f e r r o r a t Q =6

33



38 // 9 . 8 6 6D−10

39 // P r o b a b i l i t y o f e r r o r a t Q =740 // 1 . 2 8 0D−1241 // P r o b a b i l i t y o f e r r o r a t Q =842 // 6 . 1 0 6D−16

Scilab code Exa 7.41 // C a pt io n : To f i n d t he e ne rg y o f t hep ho to n i n c i d e n t on p h ot o di o de

2 / / and Minimum i n c i d e n t o p t i c a l p ow er3 // Example7 . 44 / / p ag e 2 625 clear ;

6 clc ;

7 close ;

8 h = 6.626 e -34; / / p l a n ks c o n s t a n t J / s9 C = 3 e 0 8 ; // f r e e s pa ce v e l o c i t y i n m/ s

10 B = 1 0 e 0 6 ; / / d a t a r a t e 1 0 Mb/ s e c11 tuo = 2/ B ; // 1/ t u o = h a l f t h e d a ta r a t e B12 L am b da = 8 50 e - 0 9; / / o p e r a t i n g w a ve l en g th i n nm13 E = 2 0. 7* h * C / L am bd a ;

14 Pi = E / tuo ;

15 disp (E , ’ En erg y o f t he i n c i d e n t p ho to n E = ’ )16 disp ( P i , ’ minimum i n c i d e n t o p t i c a l p ower P i = ’ )

17 disp (10* log10 ( P i * 1 0 0 0 ) , ’ minimum i n c i d e n t o p t i c a lp o we r i n dBm = ’ )

18 / / R e s u l t19 // Energy o f t he i n c i d e n t photon E = 4 . 84 1D−1820 / / minimum i n c i d e n t o p t i c a l po wer P i = 2 . 4 2 0 D−1121 / / m inimum i n c i d e n t o p t i c a l po wer i n dBm = −

7 6 . 1 6 1 0 5 9

34



7 P s = 3 ; / / l a s e r o u tp ut i n dBm

8 A P D_ s en = - 32 ; / /APD s e n s i t i v i t y i n dBm9 A l l o we d _ L os s = P s - A P D _ se n ; // i n dB10 lsc = 1; // s o ur c e c o nn e ct o r l o s s i n dB11 l jc = 2 *4 ; / / two ( j um pe r+c o n n e c t o r l o s s ) i n dB12 a lp ha = 0 .3 ; / / a t t e n u a t i o n i n dB /Km13 L = 60; / / c a b l e l e n g t h i n Km14 c a b le _ a tt = a l ph a * 6 0 ; // c a b l e a t t e n u a ti o n i n dB15 lrc = 1; // r e c e i v e r c o nn e c t o r l o s s i n dB16 s y s t e m _ m a r g i n = A l l o w ed _ L o s s - l s c - l j c - c a b l e_ a t t - l r c ;

17 disp (system_ margin , ’ The F in a l Margin i n dB = ’ )

18 / / R e s u l t

19 // ’ The F i n al Margin i n dB = 7 .

Scilab code Exa 8.3

1 // C ap ti on : Program t o c a l c u l a t e l i n k r i s e t ime2 // Example8 . 33 / / p ag e 2 914 clear ;

5 clc ;

6 close ;

7 t _t x = 1 5e - 0 9;// t r a n s mi t t e r r i s e t ime8 t _m at = 2 1e - 0 9; // m a t e r ia l d i s p e r s i o n r e l a t e d r i s e

t i m e9 t _m od = 3 .9 e - 0 9; // r i s e t im e r e s u l t i n g from modal

d i s p e r s i o n10 t _ rx = 14 e - 0 9 ; // r e c e i v e r r i s e t i m e11 t sy s = sqrt ( t _ t x ^ 2 + t _ m a t ^ 2 + t _ m o d ^ 2 + t _ r x ^ 2 )

12 disp ( t s y s * 1 e 0 9 , ’ l i n k r i s e t i m e i n nano s ec on ds t s y s= ’ )

13 / / R e s u l t14 // l i n k r i s e t im e i n nano s ec on ds t s y s = 2 9 .6 17 7 31

Scilab code Exa 8.4

1 // C a pt io n : Program t o c a l c u l a t e l i n k r i s e t im e2 // Example8 . 4

36



6 close ;

7 x = poly (0 , ’ x ’ ) ;8 G = x ^ 7 +0 + x ^ 5+ 0 +0 + x ^ 2+ x + 1;

9 C = coeff ( G ) ;

10 disp ( C ( $ : - 1 : 1 ) , ’ C o e f f i c i e n t s o f g e n er a t o r p ol yn om i a lC = ’ )

11 / / R e s u l t12 // C o e f f i c i e n t s o f g e n er at or p o l y n o m i a l C = 1 . 0 .

1 . 0 . 0 . 1 . 1 . 1 .

Scilab code Exa 8.71 / / C a p t i o n : P ro gr am t o f i n d CRC(C y c l i c R ed un da nc y C he ck )


5 clc ;

6 close ;

7 x = poly (0 , ’ x ’ ) ;

8 m = [ 1 ,1 , 1 , 1 ,0 ];

9 G = x ^ 7 + x ^ 6+ x ^ 5 + x ^ 4 + 0 + 0+ 0 + 0 ;

10 D = x ^ 3+ 0+ x + 1;

11 [R , Q ] = pdiv ( G , D )12 R = coeff ( R ) ;

13 Q = coeff ( Q ) ;

14 R = abs ( modulo ( R , 2 ) ) ;

15 Q = abs ( modulo ( Q , 2 ) ) ;

16 disp (R , ’ R e mainde r R = ’ )

17 disp (Q , ’ Q u o t i e n t Q = ’ )

18 disp ([ m R ] , ’CRC f o r t h e g i v e n i n f o r m a t i o n CRC = ’ )

19 / / R e s u l t20 / / R e m a i n d e r R =21 // 1 . 0 . 1 .

22 / / Q u o t i e n t Q =23 // 1 . 1 . 0 . 1 . 1 .24 / /CRC f o r t h e g i v e n i n f o r m a t i o n CRC =25 // 1 . 1 . 1 . 1 . 0 . 1 . 0 . 1 .

38



Scilab code Exa 8.81 / / C ap ti on : Program t o p e r c e n t a g e o f

b u r s t e r r o r d e t e c t e d by CRC2 // Example8 . 83 / / p ag e 3 094 clear ;

5 clc ;

6 close ;

7 N = 32 ;

8 P ed = 1 - ( 1/ (2 ^ N )) ;

9 disp ( P e d * 1 0 0 , ’ P er ce n t o f b u r st e r r o r d e t e ct e d by CRCf o r a l e ng t h o f 32 Ped= ’ )

10 / / R e s u l t

11 // P er ce nt o f b u r st e r r o r d e t e ct e d by CRC f o r al e n g t h o f 32 Ped = 10 0.

Scilab code Exa 8.91 / / C ap ti on : P e rc e nt o v er h ea d t o t h ei n f o r a m t i o n s tr ea m U si ng Reed−S ol om on c o de f o re r r o r c o r r e c t i o n


5 clc ;6 close ;

7 S =8; //Reed−S ol om on c od e w it h 1 b y te8 n = ( 2^ S - 1) ; // l e ng t h o f c o de d s eq ue nc e9 k = 2 3 9 ; // l e n g t h o f m es sa ge s e q ue n c e

10 r = n - k ;

11 disp (r , ’ n umber o f r ed un da n t b y t e s r = ’ )

12 disp ( ( r / k ) * 1 0 0 , ’ P e r c e n t o v e rh e a d = ’ )

13 / / R e s u l t14 / / number o f r ed un da nt b y t e s r = 1 6 .15 // P e r c e n t o v e r h e a d = 6 . 6 9 4 5 6 0 7

39



Figure 9.1: Figure for Example9.2Preamplifier

41



Figure 9.2: Figure for Example9.2quantumnoise

42



Figure 9.3: Figure for Example9.2reflectionnoise

43



3 / / p ag e 3 23

4 clear ;5 clc ;

6 close ;

7 T = 30 0; // room t e mp e ra t u re i n k e l v i n8 k B = 1 . 38 0 54 e - 2 3; / / Bo lt zm an n ’ s c o n s t a n t i n J o u l e s / k9 m = 0. 25 ; / / m o d u a l t i o n i n d e x

10 R IN _ dB = - 14 3; // R e l a t i v e i n t e n s i t y i n dB/Hz11 R IN = 1 0^ ( R I N_ dB / 1 0) ;

12 P c = ( 1 0^ ( 0/ 1 0) ) * 1 e -3 ; // p ower c ou p le d t o o p t i c a lf i b e r i n dBm

13 R = 0 . 6 ; / / R e s p o n s i v i t y A/w

14 Be = 10 e06 ; // bandwidth 10MHz15 I D = 10 e -0 9; / / d ar k c u r r e n t 1 0nA16 R eq = 7 50 ; // e q u i v a l e n t r e s i s t a n c e 7 50 ohm17 F t = 1 0^ (3 /1 0) ; / / i n 3 dB18 M = 1; // M u l t i p l i c a t i o n f a c t o r f o r p in p ho to di od e19 R = 0 . 6 ; // r e s p o n s i v i t y i n A/m20 q = 1 .6 02 e - 19 ; / / c h a r g e i n c ou l om b s21 p = 0 : -1 : -2 0;

22 P = ( 10 ^( p / 1 0) ) * 1 e -3 ;

23 C _ N_ 1 = 0 . 5 *( ( m * R * P ) ^ 2) / ( 4 * k B * T * Be * F t / R e q ) ;

24 C _N _3 = 0 .5 * m ^ 2/ ( R IN * B e ) ;

25 C _ N_ 2 = 0 . 5* m ^ 2 * R * P / ( 2* q * B e ) ;

26 figure

27 plot ( p , 1 0 * log10 ( C _ N _ 1 ) , ’ r ’ )

28 x l a b e l ( ’ R e c e i v e d O p t i c a l P ow er ( dBm ) ’ )

29 y l a b e l ( ’ C a r r i e r−to−n o i s e r a t i o ( dB ) ’ )

30 t i t l e ( ’ C a r r i e r−to−n o i s e r a t i o 1 ( P r e am p l i f i e rr e c e i v e r n o i s e ) ’ )

31 figure

32 plot ( p , 1 0 * log10 ( C _ N _ 2 ) , ’m ’ )


34 y l a b e l ( ’ C a r r i e r−

to−

n o i s e r a t i o ( dB ) ’ )35 t i t l e ( ’ C a r r i e r−to−n o i s e r a t i o 2 ( Quantum n o i s e ) ’ )

36 figure

37 plot ( p , 1 0 * log10 ( C _ N _ 3 ) * ones (1 , length ( p ) ) )


44



39 y l a b e l ( ’ C a r r i e r−to−n o i s e r a t i o ( dB ) ’ )

40 t i t l e ( ’ C a r r i e r−

to−

n o i s e r a t i o 3 ( R e f l e c t i o n n o i se ) ’ )

45



Chapter 10

Tenth chapter

Scilab code Exa 10.1

1 // C a p ti on : F i nd i ng t h e c e n t e r w a ve l en g th2 // Example10 . 13 / / p ag e 3 434 clear ;

5 clc ;

6 close ;

7 d e lt a _v = 1 4 e1 2 ; / / o p t i c a l b an dw id th8 L am b da = 1 52 0; / / s p e c t r a l band9 C = 3 e 0 8 ; // f r e e s pa ce v e l o c i t y

10 d e l t a_ L a m bd a = ( L a m b da ^ 2 ) * d e l t a _v / C ;

11 disp ( d e l t a _ L a m b d a * 1 e - 0 9 , ’ s p e c t r a l band i n nano m et er’ )

12 / / R e s u l t13 / / s p e c t r a l band i n nano m et er = 1 0 7 . 8 1 8 67


1 // C a p ti on : F i nd i ng mean f r e q u e n cy s p a c i n g


5 clc ;

6 close ;

46



7 C = 3 e 0 8 ; // f r e e s pa ce v e l o c i t y

8 d e l t a_ L a m bd a = 0 . 8 e - 09 ; // s p e c t r a l band i n m et er9 L am b da = 1 55 0 e - 09 ; / / w a v el e n g th i n m et er10 d e l ta _ v = C * d e l t a _ La m b da / L a m bd a ^ 2 ;

11 disp ( ceil ( d e l t a _ v * 1 e - 0 9 ) , ’ Mean F re q ue n cy s p a c i n g i nGHz =’ )

12 / / R e s u l t13 / / Mean F r eq u en c y s p a c i n g i n GHz = 1 0 0 .

Scilab code Exa 10.31 / / C a pt i on : P ro gra m t o f i n d c o u p l i n gr a ti o , E xc es s l o ss , I n s e r t i o n l o ss , Return l o s s

o f 2 x2 F ib e r c o u pl e r2 // Example10 . 33 / / p ag e 3 484 clear ;

5 clc ;

6 close ;

7 P 0 = 2 00 e - 06 ; // i np ut o p t i c a l power l e v e l i n w at ts8 P 1 = 90 e -0 6; // o u tp ut power a t p o rt 19 P 2 = 85 e -0 6; // o u tp ut power a t p o rt 2

10 P 3 = 6 .3 e - 09 ; // o u tp ut power a t p o rt 311 C o u p li n g _ ra t i o = ( P 2 / ( P 1 + P2 ) ) * 1 0 0;

12 E x ce s s_ l os s = 1 0* log10 ( P 0 / ( P 1 + P 2 ) ) ;

13 I n s e r ti o n _ lo s s _ 0 _1 = 1 0* log10 ( P 0 / P 1 ) ;

14 I n s e r ti o n _ lo s s _ 0 _2 = 1 0* log10 ( P 0 / P 2 ) ;

15 R e tu r n_ l os s = 1 0* log10 ( P 3 / P 0 ) ;

16 disp (Coupl ing_ratio , ’ C o up l in g r a t i o ’ )

17 disp (Excess_loss , ’ E xc es s l o s s i n dB ’ )

18 disp (Insertion_loss_0_1 , ’ I n s e r t i o n l o s s ( p or t 0 t op o rt 1 ) i n dB ’ )

19 disp (Insertion_loss_0_2 , ’ I n s e r t i o n l o s s ( p or t 0 t op o rt 2 ) i n dB ’ )

20 disp (Return_loss , ’ R et un r l o s s i n dB ’ )21 / / R e s u l t22 // C ou pl in g r a t i o23 // 4 8 . 5 7 1 4 2 924 // E x ce ss l o s s i n dB

47



25 // 0 . 5 7 9 9 1 9 5

26 // I n s e r t i o n l o s s ( p or t 0 t o p or t 1 ) i n dB27 // 3 . 4 6 7 8 7 4 928 // I n s e r t i o n l o s s ( p or t 0 t o p or t 2 ) i n dB29 // 3 . 7 1 6 1 1 0 730 // R etunr l o s s i n dB31 // − 4 5 . 0 1 6 8 9 4

Scilab code Exa 10.51 / / C a pt i on : F i n d i ng o u t pu t p o we rs a to ut pu t p or t o f 2 x2 c o u pl e r

2 // Example10 . 5

3 / / p ag e 3 504 clear ;

5 clc ;

6 close ;

7 S = sqrt ( 1 / 2 ) * [ 1 , % i ; % i , 1 ] ; // s c a t t e r i n g m at ri x8 E in = [ 1; 0] ;

9 E ou t = S * Ei n ;

10 P ou t1 = E ou t ( 1) * conj ( E o u t ( 1 ) ) ;

11 P ou t2 = E ou t ( 2) * conj ( E o u t ( 2 ) ) ;

12 disp ( P o u t 1 , ’ O utput p ower a t p o r t 1 Po ut1 = ’ )

13 disp ( P o u t 2 , ’ O utput p ower a t p o r t 2 Po ut2 = ’ )14 / / R e s u l t15 // Output power a t p o rt 1 Pout1 = 0 . 516 // Output power a t p o rt 2 Pout2 = 0 . 5


1 / / C a pt i on : Pr og ram t o f i n d w a ve g ui d e l e n g t h2 // Example10 . 63 / / p ag e 3 534 clear ;

5 clc ;6 close ;

7 k = 0 .6 /1 e - 03 ; / / c o u p l i n g c o e f f i c i e n t p e r m i l l ime t e r

8 m =1; //mode=1

48



9 L = % pi * ( m +1 ) / (2 * k ) ;

10 disp ( L * 1 e 0 3 , ’ C o u p l i n g L e ng t h i n mm L = ’ )11 / / R e s u l t12 / / C ou p li n g L en gt h i n mm L = 5 . 2 3 5 9 87 8

Scilab code Exa 10.71 / / C ap ti on : Program t o f i n d E x ce s sl o s s , S p l i t t i n g l o s s and t o t a l l o s s


5 clc ;

6 close ;7 P o we r _L o st = 5 / 10 0;

8 F T = 1 - P o we r _L o st ; / / p ow er c o u p l e d9 N = 32;

10 E x ce s s_ L os s = - 10 * log10 ( F T ^ log2 ( N ) ) ;

11 S p l i tt i n g _L o s s = - 10 * log10 ( 1 / N ) ;

12 T o t al _ L os s = E x c e ss _ L o ss + S p l i tt i n g _L o s s ;

13 disp (Excess_Loss , ’ E x c es s L o s s i n dB ’ )

14 disp (Split ting_Loss , ’ S p l i t t i n g L os s i n dB ’ )

15 disp (Total_Loss , ’ T ot al L os s e x p e ri e n c e d i n S t ar

C o u p l e r s i n dB ’ )16 / / R e s u l t17 // E xc es s L os s18 // 1 . 1 1 3 8 1 9 719 // S p l i t t i n g L o s s20 // 1 5 . 0 5 1 521 // T ot al L os s e x pe r i e n c e d i n S ta r C ou pl er s22 // 1 6 . 1 6 5 3 2


1 / / C a pt i on : Pr og ram t o W av eg ui de L en gt h d i f f e r e n c e2 // Example10 . 83 / / P ag e 3 5 74 clear ;

5 close ;

49



6 clc ;

7 d e l t a_ L a m bd a = 0 . 08 e - 0 9 ; / / w a ve l en g th s p a c i n g i nn an o m e t e r s8 L am b da = 1 55 0 e - 09 ; / / w a v el e n g th i n m e t er s9 n ef f = 1 .5 ; // e f f e c t i v e r e f r a c t i v e i n de x i n t h e

w a v e g u i d e10 C = 3 e0 8 ; // f r e e s pa ce v e l o c i t y11 d e lt a_ v 1 = 1 0 e0 9 ; / / f r e q u e n c y s p a c i n g 112 d e lt a_ v 2 = 1 30 e 0 9 ; // f r e q u e n cy s p a c i n g 213 d e l ta _ L 1 = C / ( 2 * n e ff * d e l t a _ v1 ) ;

14 d e l ta _ L 2 = C / ( 2 * n e ff * d e l t a _ v2 ) ;

15 disp ( d e l t a _ L 1 * 1 e 0 3 , ’ w av e g ui de l e ng t h d i f f e r e n c e i n

m i l l i m et er s ’ )16 disp ( d e l t a _ L 2 * 1 e 0 3 , ’ w av e g ui de l e ng t h d i f f e r e n c e i n

m i l l i m et er s ’ )

17 / / R e s u l t18 // w a v e g u i d e l e n g t h d i f f e r e n c e i n m i l l i m et er s19 // 1 0 .20 // w a v e g u i d e l e n g t h d i f f e r e n c e i n m i l l i m et er s21 // 0 . 7 6 9 2 3 0 8


1 // C a p ti on : F i b e r B ra gg G r at i ng : Peak R e f l e c t i v i t y ,C o up li ng c o e f f i c i e n t , f u l l −bandw i dt h

2 //E x ample 10 . 9 . a3 clear ;

4 close ;

5 clc ;

6 k L = [ 1 ,2 , 3] ;

7 R ma x = tanh ( k L ) ^ 2 ;

8 //E x ample 10 . 9 . b9 L = 0. 5 e - 02 ;

10 L a m b da _ B r ag g = 1 5 30 e - 0 9 ;11 n ef f = 1 .4 8;

12 d e lt a _n = 2 .5 e - 0 4;

13 e tt a = 8 2 /1 00 ;

14 k = % pi * d e l t a _n * e t t a / L a m b d a _B r a g g ;

50



15 d e l t a_ L a m bd a = ( L a m b d a _B r a g g ^ 2 ) * (( ( k * L ) ^ 2+ % p i ^ 2 )

^ 0 . 5 ) / ( % p i * n e f f * L ) ;16 disp ( k / 1 0 0 , ’ C oupl i ng c o e f f i c i e n t pe r cm k =’ )

17 disp ( d e l t a _ L a m b d a * 1 e 0 9 , ’ f u l l b a n dw i d th i n nm = ’ )

18 disp ( ’ ’ )

19 disp ( ’ kL Rmax (%) ’ )

20 disp ( ’ ’ )

21 disp ( k L , ’ kL ’ )

22 disp ( R m a x * 1 0 0 , ’Rmax ’ )

23 disp ( ’ ’ )

24 / / R e s u l t25 / / C o u p l i n g c o e f f i c i e n t p e r cm k = 4 . 2 0 9 3 2 3 5

26 // f u l l bandwi dt h i n nm = 0 .3 8 0 7 6 5227 //28 // kL Rmax (%)29 //30 // kL31 //32 // 1 . 2 . 3 .33 / / Rmax34 // 5 8 . 0 0 2 5 6 6 9 2 . 9 3 4 9 1 8 9 9 . 0 1 3 3 9 635 //

Scilab code Exa 10.101 // Capt ion : Phased−Array−Based−D e v i ce s : C ha nn el s p a c i n g i n t e rm s o f w a ve l en g th and

path−l e n g t h d i f f e r e n c e2 // Example10 .1 03 / / p ag e 3 724 clear ;

5 clc ;

6 close ;

7 L a mb da _ c = 1 55 0 e - 09 ; / / c e n t r a l d e s i g n w a ve l en g th

8 nc = 1 .4 5; // r e f r a c t i v e i nd ex o f g r a t i ng a rr ayw a v e g u i d e

9 ns = 1 .4 5; // r e f r a c t i v e i nd ex o f t e h s t a r c o u p le r10 ng = 1 .4 7; // g ro up i n de x o f g r a t i n g a r ra y w av eg ui de

51



11 x = 5 e - 0 6 ; // c e n t e r −to−c e n t e r s p a ci n g b et wee n t he

i n p u t w a v eg u i d es12 d = 5 e - 0 6 ; // c e n t e r −to−c e n t e r s p a ci n g b et wee n t heo u tp u t w a v eg u i d es

13 m =1;

14 L f = 10 e -0 3; // d i s t a n c e b et we en t r a n s m i t t e r ando b j e c t

15 d e lt a _L = m * L a mb da _ c / nc ;

16 d e l t a_ L a m bd a = ( x / L f ) *( n s * d / m ) * ( nc / n g ) ;

17 disp ( d e l t a _ L * 1 e 0 6 , ’ W aveguide l e n g t h d i f f e r e n c e i n um= ’ )

18 disp ( d e l t a _ L a m b d a * 1 e 0 9 , ’ C ha nn el s p a c i n g i n t e rm s o f

w a v e l e n g t h i n nm= ’ )19 / / R e s u l t20 // Waveguide l e n g t h d i f f e r e n c e i n um = 1 . 0 68 9 65 521 // Ch ann el s p a ci n g i n te r ms o f w av el en gt h i n nm =

3 . 5 7 5 6 8 0 3


1 // Capt ion : Phased−Array−B a se d D e v i c e s : L e n gt hd i f f e r e n c e b et we en a d j a ce n t a r ra y w av eg ui de s

2 // Example10 .1 13 / / p ag e 3 734 clear ;

5 close ;

6 clc ;

7 nc = 1 .4 5; // e f f e c t i v e r e f r a c t i v e i n d ex8 L a m bd a _ C = 1 5 50 . 5 e - 0 9; / / c e n t e r w a v el e n g th9 d e l t a_ L a m bd a = 3 2 .2 e - 0 9 ; // f r e e s p e c t r a l r an ge

10 C = 3 e 0 8 ; // f r e e s pa ce v e l o c i t y i n m/ s11 d e l ta _ L = L a m bd a _ C ^ 2 /( n c * d e l t a _ L am b d a ) ;

12 disp ( d e l t a _ L * 1 e 0 6 , ’ l e n g th d i f f e r e n c e b et wee n

a d j a ce n t a r ra y w av eg ui de s i n um = ’ )13 / / R e s u l t14 // l e n g t h d i f f e r e n c e b et we en a d j a ce n t a r ra y

w a v eg u i d es i n um = 5 1. 4 89 6 18

52



Scilab code Exa 10.121 // Capt ion : Maximum number of

c ha n ne l s t ha t can be p l ac e d i n t he t un in g r an ge2 // Example10 .1 23 / / p ag e 3 834 clear ;

5 clc ;

6 close ;

7 L am b da = 1 55 0 e - 09 ; / /DBR l a s e r o p e r a t i n g w a v el e n g th8 d e l ta _ n ef f = 0 . 00 6 5 ; //maximum i nd e x c hange9 d e l t a_ L a m b da _ t u ne = L a m bd a * d e l t a _ ne f f ; // t un i ng

r an ge i n m et er s10 d e l t a _L a m b da _ s i g na l = 0 . 02 e - 0 9 ; // s o u r ce s p e c t r a l

w id th i n m e te rs11 d e l t a _L a m b d a_ c h a n ne l = 1 0 * d e l t a _L a m b d a_ s i g n al ;

12 N = d e l t a_ L a m b da _ t u ne / d e l t a _L a m b d a_ c h a nn e l ;

13 disp (N , ’ The number c h a nn e l s t h at ca n o p e r at e i n t h i st u ni n g r an ge i s N= ’ )

14 / / R e s u l t15 // The n umber c h a nn e l s t h at can o p e ra t e i n t h i s

t un in g r an ge i s N = 5 0 . 3 75

53



Chapter 11

Eleventh chapter


1 / / C a pt i on : Pr og ram t o c a l c u l a t e P ho to n d e n s i t y2 // Example11 . 13 / / p ag e 3 974 clear ;

5 clc ;

6 close ;

7 Vg = 2 e08 ; // g ro up v e l o c i t y i n m/ s8 h = 6 .6 25 e - 34 ; / / p l a n k s c o n s t a n t9 C = 3 e 0 8 ; // f r e e s pa ce v e l o c i t y i n m/ s

10 L am da = 1 55 0 e - 09 ; / / o p e r a t i n g w a v el e n g th11 V = C / La md a; / / f r e q u e n c y i n Hz12 w = 5e - 06 ; // w i dt h o f o p t i c a l a m p l i f i e r i n m et e rs13 d = 0 .5 e - 06 ; // t h i c k n e ss o f o p t i c a l a m p l i f i e r i n

m e t e r s14 P s = 1 e -0 6; // o p t i c a l s i g n a l o f power15 N ph = P s /( V g * h* V * w* d ) ;

16 disp ( N p h , ’ The p ho to n d e n s i t y i n p ho t on s / c u b i c m et eri s Nph = ’ )

17 / / R e s u l t18 / /The p ho to n d e n s i t y i n p h ot on s / c u b i c m et er i s Nph =1.560D+16

54




1 / / C a p t i o n : P ump in g r a t e a nd z e r o−

s i g n a l g ai n2 / / E xa mp le 11 . 2 ( a ) a nd ( b )3 / / p ag e 3 974 clear ;

5 clc ;

6 close ;

7 I = 1 00 e - 03 ; / / b i a s c u r r e n t i n Amps8 w = 3e - 06 ; // a c t i v e a r ea w id th i n m et er s9 L = 5 00 e - 06 ; // a m p l i f i e r l e ng h t i n m et er s

10 d = 0 .3 e - 06 ; // a c t i v e a r e a t h i c k n e ss i n m et er s11 q = 1 .6 02 e - 19 ; / / c h a r g e i n c ou l om b s

12 R p = I / ( q* d * w* L ) ;13 disp ( R p , ’ The pumping r a t e i n e l e c t r o n s / s . c u b i cm e t er

i s Rp = ’ )

14 T uo = 0 .3 ; / / t h e c o n fi n e me n t f a c t o r15 a = 2e - 20 ; // ga i n c o e f f i c i e n t i n sq u ar e me t e r16 J = I /( w* L) ; / / b i a s c u r r e n t d e n s i t y i n Amp/ s q u r e

me t e r17 nth = 1 e24 ; // t h r e s h o l d d e n s i t y p er c u bi c m et er18 T uo r = 1 e -0 9; // Time c o n s t a n t i n s e c o nd s19 g 0 = T u o * a * T uo r * ( ( J / ( q * d )) - ( n t h / T uo r ) )

20 disp ( g 0 / 1 0 0 ,’ The z e r o

−

s i g n a l g ai n p e r cm i s g0 = ’)

21 / / R e s u l t22 / / The pumping r a t e i n e l e c t r o n s / s . c u b i cm e t er i s Rp

= 1 . 3 8 7 D+3323 / / The z e ro−s i g n a l g ai n p er cm i s g0 = 2 3. 22 92 97

Scilab code Exa 11.31 // C apt i on : Maximum i np ut pow er andmaxmimum ou tp ut power

2 / / E xa mp le 1 1 . 33 / / p ag e 4 04

4 clear ;5 clc ;

6 close ;

7 L a mb da _ p = 9 80 e - 0 9; //pump w av e l e ng t h8 L a mb da _ s = 1 55 0 e - 09 ; / / s i g n a l w a ve l en g th

55



5 clc ;

6 close ;7 L a mb da _ p = 9 80 e - 0 9; / /pump w a v e l e n g t h i n m e t e r s8 L a mb da _ s = 1 54 0 e - 09 ; // s i g n a l w av el en gt h i n m et er s9 P s_ o ut = 1 0e - 0 3; // o u tp ut s i g n a l power

10 P s_ in = 1 e - 03 ; / / i n p u t s i g n a l p ower11 P p _i n = ( L a m b d a_ s / L a m b d a _p ) * ( P s _ ou t - P s _ in )

12 disp ( P p _ i n * 1 e 0 3 , ’Pump p ower i n m i l l i w at ts P p i n = ’ )

13 / / R e s u l t14 / /Pump p ower i n m i l l i w a tt s P p i n = 1 4 . 1 4 2 8 5 7

Scilab code Exa 11.81 // C a pt io n : OSNR f o r d i f f e r e n t ASE n o i s e l e v e l


5 clc ;

6 close ;

7 P _A S E1 = - 22 ; / /ASE l e v e l i n dBm8 P _A S E2 = - 16 ; / /ASE l e v e l i n dBm9 Po ut = 6; // a m p l i f i e d s i g n a l l e v e l i n dBm

10 O SN R1 = P ou t - P _A SE 1 ; // Op t i c a l SNR i n dBm11 O SN R2 = P ou t - P _A SE 2 ; // Op t i c a l SNR i n dBm12 disp ( O S N R 1 , ’ Op ti ca l SNR in dBm OSNR = ’ )

13 disp ( O S N R 2 , ’ Op ti ca l SNR in dBm OSNR = ’ )

14 / / R e s u l t15 / / O p t i c a l SNR i n dBm OSNR = 2 8 .16 / / O p t i c a l SNR i n dBm OSNR = 2 2 .

Scilab code Exa 11.91 // C ap ti on : N o is e p e n al t y f a c t o r2 // Example11 . 9

3 / / p ag e 4 144 clear ;

5 clc ;

6 close ;

7 G = [ 1 0 ^ ( 3 0 / 1 0 ) , 1 0 ^ ( 20 / 1 0 ) ] ; / / A m p l i f i e r Ga in

57



8 for i = 1: length ( G )

9 F p at h ( i ) = ( 1 / G ( i )) * ( ( G ( i ) - 1) / log ( G ( i ) ) ) ^ 2 ;10 disp (10* log10 ( F p a t h ( i ) ) , ’ N oi se p e na l ty f a c t o r i nd B F p a t h = ’ ) ;

11 disp ( G ( i ) , ’ f o r a g ai n o f G = ’ ) ;

12 end

13 / / R e s u l t14 // N oi s e p e na l t y f a c t o r i n dB F path = 1 3. 2 0 45 7 115 // f o r a g ai n o f G = 1 0 0 0.16 // N oi s e p e na l t y f a c t o r i n dB F path = 6 .6 4 7 79 0 217 // f o r a g a i n o f G = 1 0 0 .

Scilab code Exa 11.101 / / C a p t i o n : U pp er b ou nd o n i n p u to p t i c a l s i g n a l power

2 // Example11 .1 03 / / p ag e 4 154 clear ;

5 clc ;

6 close ;

7 e tt a = 0 .6 5; / /Quantum e f f i c i e n c y8 nsp = 2; // p o pu l at i on i n v e r s i o n be t we en two l e v e l s

9 R = 50 ; // l o ad r e s i s t a n c e inoh ms10 L am b da = 1 55 0 e - 09 ; // o p e r a t i n g w a ve l en g th i n m e te r s11 T = 3 0 0 ; // room t e m pe r a tu r e i n k e l v i n s12 k B = 1 . 38 0 54 e - 2 3; / / b o lt zm a nn ’ s c o n s t a n t13 h = 6 .6 25 6 e - 34 ; / / p l an k ’ s c o n s t a n t14 C = 3 e 0 8 ; // f r e e s pa ce v e l o c i t y i n m/ s15 V = C / La mb da ; // f r e q u e n cy i n Hz16 q = 1 .6 02 e - 19 ; / / c h a r g e i n c ol u mb s17 P s _i n = k B * T * h *V / ( R * n sp * ( e t t a ^ 2) * ( q ^ 2 ) ) ;

18 disp ( P s _ i n * 1 e 0 6 , ’ U pper b ound o n i n p u t o p t i c a l s i g n a lpower i n m ic ro w at ts P s i n= ’ )

19 / / R e s u l t20 // Upper bound o n i n pu t o p t i c a l s i g n a l power i n m ic ro

w a tt s P s i n = 4 89 .8 16 35

58



Chapter 12

Twelve chapter

Scilab code Exa 12.11 // C ap ti on : E f f e c t i v e l e ng t h o f f i b e r2 // Example12 . 13 / / p ag e 4 324 clear ;

5 clc ;

6 close ;

7 L = 75; // a m p l i f i e r s p ca i ng i n k i l o me t e r8 a lp ha = 4 .6 1 e - 02 ; // f i b e r a t t e n u a t io n p er Km9 Le ff = (1 - exp ( - a l p h a * L ) ) / a l p h a ;

10 disp ( L e f f , ’ E f f e c t i v e l en g t h o f f i b e r i n k i l o m e t e r sL e f f = ’ )

11 / / R e s u l t12 // E f f e c t i v e l e n gt h o f f i b e r i n k i l o m e t e r s L e ff =

2 1 . 0 0 8 4 9 4


1 // C ap ti on : C a l c u l a t i o n o f S ti mu l a te d B r i l l o u i nS c a t t e r i n g ( SBS ) t h r e s h o l d p ower


5 clc ;

6 close ;

59



7 d e lt a_ V B = 2 0 e0 6 ; // B r i l l o u i n l i n e w i d t h i n Hz

8 A ef f = 5 5e - 1 2; // e f f e c t i v e c ro s s−

s e c t i o n a l a re a o f t he p r o pa g a ti n g wave i n s q ua r e m et er9 L ef f = 2 0 e0 3 ; // e f f e c t i v e l e n g th

10 b = 2; // p o l a r i z a t i o n f a c t o r11 g B = 4 e -1 1; // B r i l l o u s ga i n c o e f f i c i e n t m/W12 d e lt a _V s ou r ce = 4 0 e0 6 ; // o p t i c a l s o ur c e l i n e wi d t h i n

Hz13 P th = 2 1 *( A e f f * b / ( g B * L ef f ) ) * ( 1 +( d e l t a_ V s o ur c e /

d e l t a _ V B ) ) ;

14 disp ( P t h * 1 e 0 3 , ’ SBS t h r e s h o l d power i n m i l l i w at tsPth=’ )

15 / / R e s u l t16 //SBS t h r e s h o l d power i n m i l l i w at ts Pth= 8 . 66 2 5

Scilab code Exa 12.31 / / C a p t i o n : F ou r−w av e mi x i ng−c a l c u l a t i o n o f power g e ne r a t ed due t o t he

2 // i n t e r a c t i o n o f s i g n a l s a t d i f f e r e n t f r e q u e n c i e s3 // Example12 . 34 / / p ag e 4 385 clear ;

6 clc ;

7 close ;

8 c h i1 1 11 = 6 e - 15 ; // T hi rd o r d er n o n l i n e a rs u c e p t i b i l i t y c u bi c me t er /W. s

9 D =3; // d e g e n er a t i n g f a c t o r10 L ef f = 2 2 e0 3 ;// e f f e c t i v e l e n g t h i n m e te r s11 A ef f = 6 .4 e - 1 1; // e f f e c t i v e c ro s s−s e c t i o n a l a re a o f

t h e f i b e r i n s qu ar e me t er12 e tt a = 0 .0 5; // quantum e f f i c i e n c y13 L am b da = 1 54 0 e - 09 ; // W av el en gt h i n s i n g l e mode

f i b e r s i n me t er

14 C = 3 e 0 8 ; // f r e e s pa ce v e l o c i t y i n m/ s e c15 a l ph a = 0 . 04 6 1 ; / / a t t t e n u a t i o n p e r Km16 L = 75 ; // f i b e r l i n k l e ng t h i n Km17 P = 1e - 03 ; // e ac h c ha nn el i np ut power o f 1 m i l l i

w a t t s

60



18 n = 1. 48 ; // r e f r a c t i v e i nd ex

19 k = ( ( 32 * ( % p i ^ 3) * c h i 1 1 11 ) / ( ( n ^ 2 ) * L a m bd a * C ) ) * ( L e ff /A e f f ) ; // n o n l i ne a r i n t e r a c t i o n c o ns t a n t20 P 1 12 = e t ta * ( D ^ 2 ) * ( k ^ 2) * ( P ^ 3 ) * exp ( - a l p h a * L ) ;

21 disp ( P 1 1 2 * 1 e 0 3 , ’ Power g e n er a t ed due t o i n t e r a c t i o no f s i g n a l s a t d i f f e r e n t f r e q . i n m i l l i w a t t s P112

= ’ )

22 / / R e s u l t23 // Power g en e r at ed due t o i n t e r a c t i o n o f s i g n a l s a t

d i f f e r e n t f r e q . i n m i l l i w a tt s P112= // 5 . 7 9 8D−08

Scilab code Exa 12.41 // C apt i on : F ul l−

w id th H a lf −

Maximum(FWHM) s o l i t o n p u l s e n o r m a l i z e d t i me


5 clc ;

6 close ;

7 T s = [ 15 e - 12 , 5 0e - 1 2] ; / /FWHM s o l i t o n p u l s e w i d t h8 T o = T s / 1. 7 62 7 ;

9 disp ( T o * 1 e 1 2 , ’ N o rm a l iz e d t i me f o r FWHM s o l i t o n p u l s e

i n p i co s e c on d s To = ’ )10 / / R e s u l t11 / / N or m al i ze d t im e f o r FWHM s o l i t o n p u l s e i n p i c o

s e c on ds To = [ 8 .5 0 9 6 7 27 2 8 . 3 65 5 7 6 ]

Scilab code Exa 12.51 / / C ap ti on : C a l c u l a t i o n o f n o r m al i z e dd i s t a n ce p a ra me t e r f o r d i s p e r s i o n s h i f t e d f i b e r


5 clc ;

6 close ;

7 T s = 20 e -1 2; / /FWHM s o l i t o n p u l s e w id th i n s e c o n d s8 D = 0 .5 e - 06 ; // d i s p e r s i o n o f t he f i b e r p s / (nm . km)

61



9 L am b da = 1 55 0 e - 9; / / w a v el e n g th i n m et er

10 C = 3 e 0 8 ; // f r e e s pa ce v e l o c i t y i n m/ s11 L d is p = 0 . 3 22 * 2 * % p i * C *( T s ^ 2 ) / ( ( L a mb d a ^ 2 ) * D ) ;

12 disp ( L d i s p / 1 0 0 0 , ’ d i s p e r s i o n l e n g th i n Km L di sp = ’ )

13 / / R e s u l t14 // d i s p e r s i o n l e n g th i n Km Ld is p = 2 0 2. 1 0 80 4

Scilab code Exa 12.61 / / C ap ti on : Program t o c a l c u l a t es o l i t o n p ea k p ower


5 clc ;

6 close ;

7 L am b da = 1 55 0 e - 9; / / w a v el e n g th i n m e t er s8 n 2 = 2 .6 e - 20 ; / / po we r i n s q u a r e m et er /w9 Aeff = 50 e -12; // e f f e c t i v e a re a i n s qu ar e me t e r

10 L di sp = 2 02 e 0 3 ; // d i s p e r s i o n l e ng t h i n m et er s11 P p ea k = ( A e f f / ( 2* % p i * n 2 ) ) * ( L a mb d a / L d i sp ) ;

12 disp ( P p e a k * 1 e 0 3 , ’ S o l i t o n peak power i n m i l l i w at tsP pe ak =’ )

13 / / R e s u l t14 // S o l i t o n pea k power i n m i l l i w at ts Ppeak =

2 . 3 4 8 5 3 5 4

Scilab code Exa 12.71 / / C a p t i o n :FWHM s o l i t o n p u l s e w i d t hand f r a c t i o n o f b i t s l o t o cc up ie d by a s o l i t o n


5 clc ;

6 close ;

7 //E x ample 12 . 7 . a8 L di sp = 1 00 e 0 3 ; // d i s p e r i s o n l e ng t h i n me te r9 o me ga = 4 68 2; // o s c i l l a t i o n p e r i o d

62



10 L I = o me ga * L d is p ;

11 disp ( L I , ’ i n t e r a c t i o n d i s t a n c e i n me t e r LI= ’ )12 //E x ample 12 . 7 . b13 D = 0 .5 e - 06 ; // d i s p e r i s o n o f f i b e r i n ps /nm .km14 C = 3 e 0 8 ; // f r e e s pa ce v e l o c i t y15 S 0 = 8 ; // n o rm a li z ed s e p a r a t i o n o f n e i g h no r i n g

s o l i t o n s16 B = 1 0 e 0 9 ; / / d a t a r a t e 1 0 Gb/ s e c17 L am b da = 1 55 0 e - 9; / / w a v el e n g th i n m e t er s18 B et a2 = ( L a mb da / ( 2* % p i ) );

19 L T = ( C * exp ( S 0 ) ) / ( 1 6 * D * B ^ 2 * ( B e t a 2 ^ 2 ) * ( S 0 ^ 2 ) ) ;

20 disp ( L T * 1 e 0 3 , ’ T ot al t r a n s m i s s i o n d i s t a n c e i n Km LT =

’ )21 //E x ample 12 . 7 . c22 T s = 0 . 88 1 /( S 0 * B );

23 disp ( T s * 1 e 1 2 , ’FWHM s o l i t o n p u l s e w id th i n p i c os e c o n ds Ts = ’ )

24 //E x ample 12 . 7 . d25 T s_ TB = 0 . 88 1/ S 0 ;

26 disp ( T s _ T B * 1 0 0 , ’ F ra c t i o n o f t h e b i t s l o t o cc up i e d bya s o l i t o n i n p e rc e nt a ge Ts TB= ’ )

27 / / R e s u l t28

// i n t e r a c t i o n d i s t a n c e i n m et er LI = 4 . 6 8 2D+0829 / / T o t a l t r a n s m i s s i o n d i s t a n c e i n Km LT = 2 . 8 7 0 D+1130 / /FWHM s o l i t o n p u l s e w id th i n p i c o s e c o nd s Ts =

1 1 . 0 1 2 531 // F ra ct io n o f t h e b i t s l o t o cc up ie d by a s o l i t o n i n

p e r c e n t a g e Ts TB = 1 1 . 0 1 2 5

63



Chapter 13

Thirteen chapter

Scilab code Exa 13.11 / / C ap ti on : C a l c u l a t i o n o f p owe rb ud g et f o r o p t i c a l l i n k


5 clc ;

6 close ;

7 N = [ 5 ,1 0 ,5 0] ; / / number s t a t i o n s8 a lp ha = 0 .4 ; / / a t t e n u a t i o n i n dB /Km9 L _t ap = 1 0; // c ou pl i n g l o s s i n dB

10 L _t h ru = 0 .9 ; // c o u p l e r t hr ou gh pu t i n dB11 Li = 0. 5; // I n t r i n s i c c o u pl e r l o s s i n dB12 Lc = 1. 0; / / c o u p le r−to− f i b e r l o s s i n dB13 L = 0 . 5 ; // l i n k l e n g th i n Km14 f i be r _L o ss = a lp ha * L ; // f i b e r l o s s i n dB15 P b u dg e t = N * ( a l p ha * L + 2 * L c + L i + L _ th r u ) - a l p ha * L - 2 *

L _ t h r u + 2 * L _ t a p ;

16 disp (fiber_Loss , ’ f i b e r l o s s i n dB f o r L =500 m ’ )

17 disp (Pbu dget , ’ p ower b ud ge t i n dB f o r o p t i c a l l i n k

when N = 5 , 10 and 50 s t a t i o n s r e s p e c t i v e l y = ’ )18 / / R e s u l t19 // f i b e r l o s s i n dB f o r L =500 m20 // 0 . 2

64



Scilab code Exa 13.31 // C ap ti on : C a l c u l a t i o n o f w or st

c a s e D yn am ic R an ge2 // Example13 . 33 / / p ag e 4 654 clear ;

5 clc ;

6 close ;

7 N = [ 5 , 1 0 ] ; // number o f s t a t i o n s8 a lp ha = 0 .4 ; / / a t t e n u a t i o n i n dB /Km9 L = 0 . 5 ; // l i n k l e n g th i n Km

10 Lc = 1. 0; / / c o u p le r−to− f i b e r l o s s i n dB11 L _t h ru = 0 .9 ; // c o u p l e r t hr ou gh pu t i n dB

12 Li = 0. 5; // I n t r i n s i c c o u pl e r l o s s i n dB13 D R = ( N - 2 ) * ( a l ph a * L + 2 * L c + Li + L _ t h ru ) ;

14 disp ( D R , ’ worst−c a s e d ya nmi c r a ng e i n dB f o r N =5 a nd10 r e s p e c t i v e l y DR = ’ )

15 / / R e s u l t16 / / w o r s t−c a s e dyanmic r an ge i n dB f o r N =5 a nd 10

r e s p e c t i v e l y DR =17 // 1 0 . 8 2 8 . 8


1 // C a p ti on : C a l c u l a t i o n o f po wer m ar gi n b et we ent r a n s m i t t e r a nd r e c e i v e r f o r S ta r a r c h i t e c t u r e s


5 close ;

6 clc ;

7 N = [ 10 , 5 0] ; // number o f s t a t i o n s8 a lp ha = 0 .4 ; / / a t t e n u a t i o n i n dB /Km9 L = 0.5 ; / / d i s t a n c e i n Km

10 L e x ce s s = [ 0 . 75 , 1 .2 5 ]; // e x c e s s l o s s i n dB f o r N =10a nd 5 0

11 Lc = 1. 0; // c o n ne c to r l o s s i n dB12 P s _P r ( 1 ) = L e x ce s s ( 1 ) + a l ph a * 2 * L + 2 * L c + 10 * log10 ( N ( 1 ) ) ;

13 P s _P r ( 2 ) = L e x ce s s ( 2 ) + a l ph a * 2 * L + 2 * L c + 10 * log10 ( N ( 2 ) ) ;

66



14 disp ( P s _ P r ( 1 ) , ’ The p ow er m ar gi n i n dB b et we en t h e

t r a n s mi t t e r and r e c e i v e r f o r N=10 i s Ps−

P r = ’ )15 disp ( P s _ P r ( 2 ) , ’ The p ow er m ar gi n i n dB b et we en t h et r a n s mi t t e r and r e c e i v e r f o r N=50 i s Ps−P r = ’ )

16 / / R e s u l t17 / /The po wer m ar gi n i n dB b et we en t h e t r a n s m i t t e r and

r e c e i v e r f o r N=10 i s Ps−Pr = 1 3 . 1 518 / /The po wer m ar gi n i n dB b et we en t h e t r a n s m i t t e r and

r e c e i v e r f o r N=50 i s Ps−P r = 2 0 . 6 3 9 7

Scilab code Exa 13.51 / / C a p t i o n : D e t e r m i n a t i o n o f maximuml e ng t h o f mul ti mode f i b e r l i n k


5 clc ;

6 close ;

7 L _O M2 = 4 0; // l e n g t h o f OM2 f i b e r8 L _O M3 = 1 00 ; / / l e n g t h o f OM3 f i b e r9 B W_ O M2 = 5 00 e 0 6 ;/ / b an dw id th o f OM2 f i b e r

10 B W_ O M3 = 2 00 0 e 06 ; / / b an dw id th o f OM3 f i b e r

11 L m ax = L _ OM 2 * ( B W _ O M3 / B W _O M 2 ) + L _ OM 3 ;12 disp ( L m a x , ’ The maximum l i n k l e n g t h i n m et er i s Lmax

= ’ )

13 / / R e s u l t14 / / The maximum l i n k l e n g t h i n m et er i s Lmax = 2 6 0 .

67



Chapter 14

Fourteen chapter

Scilab code Fig 14.10

1 / / C a p t i o n : P e r f o r m a n c e M ea s ur em e nt a nd M o n i t o r i n g2 // F ig ur e : 1 4 . 1 0 P l o t t i n g p u l se s ha pe o f g a u ss i an

d i s t r i b u t i o n3 / / and d e t e rm i n i n g 3−dB o p t i c a l and e l e c t r i c a l

bandw i dt h4 clear ;

5 close ;

6 clc ;

7 s ig ma = 1;8 t = - 3* s i gm a : 0 . 01 : 3* s i g ma ;

9 p = ( 1/ ( s ig ma * sqrt ( 2 * % p i ) ) ) * exp ( - t ^ 2 . / ( 2 * s i g m a ^ 2 ) ) ;

10 f d B _o p t i ca l = 0 . 18 7 / s i g ma ;

11 f d B _ el e c t ri c a l = 0 . 13 3 / s i g ma ;

12 disp (fdB_optical , ’ f d B o p t i c a l ’ )

13 disp (fdB_e lectrical , ’ f d B e l e c t r i c a l ’ )

14 plot ( t , p , ’ r ’ )

15 x l a b e l ( ’ T ime t ’ )

16 y l a b e l ( ’ R e l a t i v e p u l s e a m pl i tu d e P ( t ) ’ )

17 t i t l e ( ’ F ig ur e : 1 4 . 1 0 D e f i n i t i o n s o f p ul se−

s h a p ep a r a m e t e r s ’ )

18 xgrid (1)

19 / / R e s u l t20 // f d B o p t i c a l = 0 . 1 8 7

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Figure 14.1: Performance Measurement and Monitoring

21 // f d B e l e c t r i c a l = 0 . 1 33

optical_fiber_communication

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