Y x z a1 y x z 0a x n1 n2 n3 M1M2M3 k1 k2 k3 TE mode X=0 Continuous.

20
y x z a1 y x z 0 a x n1 n2 n3 M1 M2 M3 k1 k2 k3 x k e A 1 1 x k e B 1 1 x ik e A 2 2 x ik e B 2 2 TE mode x ik x ik x k x k e B e A e B e A 2 2 1 1 2 2 1 1 X=0 2 2 2 2 1 1 1 1 B ik A ik B k A k ) ( x E y Continuous ) ( x E x y Continuous 2 2 1 1 B A B A 2 1 2 1 1 1 1 1 B k A k B k A k 2 2 1 2 2 1 1 1 ) ( ) ( 2 B ik k A ik k A k 2 2 1 2 2 1 1 1 ) ( ) ( 2 B ik k A ik k B k 2 2 2 1 2 1 2 1 2 1 1 1 1 2 1 B A ik k ik k ik k ik k k B A 2 1 2 1 2 1 2 1 1 1 2 1 ik k ik k ik k ik k k M

Transcript of Y x z a1 y x z 0a x n1 n2 n3 M1M2M3 k1 k2 k3 TE mode X=0 Continuous.

y

xz

a1

y

xz

0 a

x

n1

n2

n3

M1 M2 M3

k1

k2

k3

xkeA 11

xkeB 11

xikeA 22

xikeB 22

TE mode

xikxikxkxk eBeAeBeA 22112211

X=0

22221111 BikAikBkAk

)(xEy Continuous

)(xEx y

Continuous

2211 BABA

21211111 BkAkBkAk

22122111 )()(2 BikkAikkAk

22122111 )()(2 BikkAikkBk

2

2

2121

2121

11

1

2

1

B

A

ikkikk

ikkikk

kB

A

2121

2121

11 2

1

ikkikk

ikkikk

kM

t

BE

HjE

jE

H

00

ˆˆˆ

yEzyx

zyx

E

)(ˆ)0(ˆˆ

)(ˆ)0(ˆˆ

x

Ezy

z

Ex

x

Ezy

z

Ex

yy

yy

x

Ey

H

Continuous @ z=0 Continuous @ z=0

Why?

y

xz

a1

0 ax

n1

n2

n3

M1 M2 M3

k1

k2

k3

xkeA 11

xkeB 11

xikeA 22

xikeB 22

TE mode

2121

2121

11 2

1

ikkikk

ikkikk

kM

xikeA 22

xikeB 22

xkeA 33

xkeB 33

xkxkxikxik eBeAeBeA 33223322

x=a

akakaikaik eBeAeBeA 33223322

akakaikaik eBkeAkeBikeAik 332233332222

akakaikaik eBikeAikeBikeAik 332232322222

akakaik eBkikeAkikeAik 33233233222 )()(2

akakaik eBkikeAkikeBik 33233233222 )()(2

3232

3232

23 2

1kikkik

kikkik

ikM

2

21

1

1

B

AM

B

A

ak

ak

aik

aik

eB

eAM

eB

eA3

3

2

2

3

33

2

2

ak

ak

aik

aik

eB

eA

kikkik

kikkik

ikeB

eA3

3

2

2

3

3

3232

3232

22

2

2

1

0 ax

n1

n2

n3

M1 M2 M3

k1

k2

k3

xkeA 11

xkeB 11

xikeA 22

xikeB 22

TE mode

2121

2121

11 2

1

ikkikk

ikkikk

kM

xikeA 22

xikeB 22

xkeA 33

xkeB 33

3232

3232

23 2

1kikkik

kikkik

ikM

2

21

1

1

B

AM

B

A

ak

ak

aik

aik

eB

eAM

eB

eA3

3

2

2

3

33

2

2

2

2

2

2

2

2

2

2

0

0

B

A

e

e

eB

eAaik

aik

aik

aik

aik

aik

aik

aik

eB

eA

e

e

B

A2

2

2

2

2

2

2

2

0

0

aik

aik

eB

eAM

B

A2

2

2

22

2

2

aik

aik

e

eM

2

2

0

02

aik

aik

eB

eAMM

B

A2

2

2

221

1

1

ak

ak

eB

eAMMM

B

A3

3

3

3321

1

1

0 ax

n1

n2

n3

M1 M2 M3

k1

k2

k3

xkeA 11

xkeB 11

xikeA 22

xikeB 22

TE mode

2121

2121

11 2

1

ikkikk

ikkikk

kM

xikeA 22

xikeB 22

xkeA 33

xkeB 33

3232

3232

23 2

1kikkik

kikkik

ikM

aik

aik

e

eM

2

2

0

02

ak

ak

eB

eAMMM

B

A3

3

3

3321

1

1

ak

ak

eB

eA

MM

MM

B

A3

3

3

3

2221

1211

1

1

0

0 33

2221

1211

1

akeA

MM

MM

B

akeAM 33110

akeAMB 33211

011 M

2

21

1

0

B

AM

B

1

11

2

2 0

BM

B

A

0 ax

n1

n2

n3

M1 M2 M3

k1

k2

k3

xkeA 11

xkeB 11

xikeA 22

xikeB 22

TE mode

2121

2121

11 2

1

ikkikk

ikkikk

kM

xikeA 22

xikeB 22

xkeA 33

xkeB 33

3232

3232

23 2

1kikkik

kikkik

ikM

aik

aik

e

eM

2

2

0

02

ak

ak

eB

eAMMM

B

A3

3

3

3321

1

1

2

21

1

0

B

AM

B

1

11

2

2 0

BM

B

A

3

3321

1

0

B

AMMM

B

1

1

3

3 03

3

BM

eB

eAak

ak

clear;clf;lamda = 1.5; %umn1 = 1.5;n2 = 1.6;n3 = 1.5;k0 = 2*pi/lamda;dn = n2 - n3;N = 100000;neff = n3+dn/N:dn/N:n2-dn/N;beta = k0.*neff;k1 = (beta.^2-k0^2*n1^2).^.5;k2 = (k0^2*n2^2-beta.^2).^.5;k3 = (beta.^2-k0^2*n3^2).^.5;d = 5; %umnm = 0;for m = 2:length(beta) M1(1,1) = (k1(m)+i*k2(m)); M1(1,2) = (k1(m)-i*k2(m)); M1(2,1) = (k1(m)-i*k2(m)); M1(2,2) = (k1(m)+i*k2(m)); M1 = M1./(2*k1(m)); M2(1,1) = exp(i*k2(m)*d); M2(2,1) = 0; M2(1,2) = 0; M2(2,2) = exp(-i*k2(m)*d); M3(1,1) = (k3(m)+i*k2(m)); M3(1,2) = (-k3(m)+i*k2(m)); M3(2,1) = (-k3(m)+i*k2(m)); M3(2,2) = (k3(m)+i*k2(m)); M3 = M3./(i*2*k2(m)); M = M1*M2*M3; M11(m) = M(1,1); I11(m) = abs(M11(m)); if I11(m)<1e-3 if I11(m)>I11(m-1) nm = nm +1; gneff(nm) = neff(m-1); else end else end endplot(neff, I11);zoom on;nmn = 1;ggneff(1) = gneff(1); for m = 2:nm if (gneff(m)-gneff(m-1))>1e-3 nmn = nmn+1; ggneff(nmn) = gneff(m); % effective index endend

%calculate model profilem = 1;betam = k0.*ggneff(m);k1m = (betam.^2-k0^2*n1^2).^.5;k2m = (k0^2*n2^2-betam.^2).^.5;k3m = (betam.^2-k0^2*n3^2).^.5; M1(1,1) = (k1m+i*k2m); M1(1,2) = (k1m-i*k2m); M1(2,1) = (k1m-i*k2m); M1(2,2) = (k1m+i*k2m); M1 = M1./(2*k1m); M2(1,1) = exp(i*k2m*d); M2(2,1) = 0; M2(1,2) = 0; M2(2,2) = exp(-i*k2m*d); M3(1,1) = (k3m+i*k2m); M3(1,2) = (-k3m+i*k2m); M3(2,1) = (-k3m+i*k2m); M3(2,2) = (k3m+i*k2m); M3 = M3./(i*2*k2m); M = M1*M2*M3;V1 = [0 1]';B1 = V1(2);V2 = M1^-1*V1;A2 = V2(1);B2 = V2(2);x1 = -10:0.001:0;y1 = B1.*exp(k1m.*x1);figure (2)plot(x1,y1);hold on;x2 = 0:0.001:d;y2 = A2.*exp(-i*k2m.*x2) + B2.*exp(i*k2m*x2);V3 = M^-1*V1;A3 = V3(1)*exp(k3m*d);B3 = 0; %V3(2)*exp(-k3m*d); % = 0plot(x2,y2, 'r');x3 = d:0.001:10;y3 = A3.*exp(-k3m.*x3) + B3.*exp(k3m*x3);plot(x3,y3, 'b');hold off;zoom on;

One waveguide.m

1.51 1.52 1.53 1.54 1.55 1.56 1.57 1.58 1.59

-3

-2

-1

0

1

2

3

4

5

6

M(1,1) = 0

-10 -8 -6 -4 -2 0 2 4 6 8 10-1.5

-1

-0.5

0

0.5

1

1.5

mode profile

01

221

21

20

0

221

2

21

21

20

0

21 )(1

)(1

)()(dx

ddx

nkdxx

dx

d

nkdxxx

021

21

21

20

0122

121

20

1|)(

1dx

dx

d

dx

d

nkdx

dx

nk

1

02

21

21

20

0122

121

20

1|)(

1

ddx

d

nkdx

dx

nk

0

22

2

121

21

20

01

221

21

20

0122

121

20

1|

1|)(

1dx

dx

d

nkdx

d

nkdx

dx

nk

0

2121

21

20

22

21

200

12

21

21

20

0122

121

20

|1

|)(1

dxnk

nk

dx

d

nkdx

dx

nk

0

2121

21

20

22

21

200

12

21

21

20

0122

121

20

0

21 |1

|)(1

dxnk

nk

dx

d

nkdx

dx

nkdx

aaaa

dxnk

nk

dx

d

nkdx

dx

nkdx

0 2121

22

20

22

22

20

012

21

22

20

01

221

22

20

0 21 |1

|)(1

0

2122

21

20

01

2012

0

2121

21

20 ||)( dxnk

dx

d

dx

dxdxnk

01

2012

0

2121

22 ||)(

dx

d

dx

dxdx

aaaa

dxnkdx

d

dx

dxdxnk

0 2122

22

2001

20

120 21

21

22

20 ||)(

aaa

dx

d

dx

dxdx 01

20

120 21

21

22 ||)(

aaaa

dxnk

nk

dx

d

nkdx

dx

nkdx 212

123

20

22

23

20

12

21

23

20

122

123

20

21 |1

|)(1

aaaa

dxnkdx

d

dx

dxdxnk 21

22

23

201

21221

21

23

20 ||)(

aaa dx

d

dx

dxdx ||)( 1

21221

21

22

01

2012

0

2121

22 ||)(

dx

d

dx

dxdx

aaa

dx

d

dx

dxdx 01

20

120 21

21

22 ||)(

02121

22

dx

dxbxaxEi

ii )()()(

dxxxEa ii

)()(

1)()(

dxxx ji

0 ax

n1

n2

n3

M1 M2 M3

k1

k2

k3

xkeA 11

xkeB 11

xikeA 22

xikeB 22

TE mode

xikeA 22

xikeB 22

xkeA 33

xkeB 33

a+b1

ba a2

a+a2+b1

M5 = M1M4M6 = M2

M7 = M3

)(4

2 baxikeA

)(4

2 baxikeB

Same waveguide

)(3

3' baxkeA

)(3

3' baxkeB

xkeA 35

xkeB 35

'

'

0

0

3

3

3

3

3

3

3

3

B

A

e

e

eB

eAbk

bk

ak

ak

4

45

3

3

'

'

B

AM

B

A

)(3

3 bakeA

)(3

3 bakeB

'3A

'3B

ak

ak

eB

eAMMM

B

A3

3

3

3321

1

1

bk

bk

e

eM

3

3

0

04

'

'

3

34321

1

1

B

AMMMM

B

A

4

454321

1

1

B

AMMMMM

B

A

15 MM

0 ax

n1

n2

n3

M1 M2 M3

k1

k2

k3

xkeA 11

xkeB 11

xikeA 22

xikeB 22

TE mode

xikeA 22

xikeB 22

xkeA 33

xkeB 33

a+b1

ba a2

a+a2+b1

M5 = M1M4 M7 = M3

)(4

2 baxikeA

)(4

2 baxikeB

)(3

3' baxkeA

)(3

3' baxkeB

)(5

3 abaxkeA

)(5

3 abaxkeB

)(3

3 bakeA

)(3

3 bakeB

'3A

'3B

)(4

4' abaxikeA

)(4

4' abaxikeB

ak

ak

aik

aik

eB

eAM

eB

eA3

3

2

2

3

33

2

2

)(2

2' axikeA

)(2

2 axikeB

'2A

'2B

aikeA 22

aikeB 22

'

'

0

0

4

4

4

4

4

4

B

A

e

e

B

Aaik

aik

M6

aikeA 44

aikeB 44

'

'

4

4654321

1

1

B

AMMMMMM

B

A

aik

aik

e

eM

4

4

0

06

)(3

3' axkeA

)(3

3' axkeB

akeA 33

akeB 33

0 ax

n1

n2

n3

M1 M2 M3

k1

k2

k3

xkeA 11

xkeB 11

xikeA 22

xikeB 22

TE mode

xikeA 22

xikeB 22

xkeA 33

xkeB 33

a+b1

ba a2

a+a2+b1

M5 = M1M4 M7 = M3

)(4

2 baxikeA

)(4

2 baxikeB

)(3

3' baxkeA

)(3

3' baxkeB

)(5

3 abaxkeA

)(5

3 abaxkeB

)(3

3 bakeA

)(3

3 bakeB

'3A

'3B

)(4

4' abaxikeA

)(4

4' abaxikeB

ak

ak

aik

aik

eB

eAM

eB

eA3

3

2

2

3

33

2

2

)(2

2' axikeA

)(2

2 axikeB

'2A

'2B

aikeA 22

aikeB 22

5

57

4

4

'

'

B

AM

B

A

M6

aikeA 44

aikeB 44

'

'

4

4654321

1

1

B

AMMMMMM

B

A

aik

aik

e

eM

4

4

0

06

)(3

3' axkeA

)(3

3' axkeB

akeA 33

akeB 33

'

'

0

0

4

4

4

4

4

4

B

A

e

e

B

Aaik

aik

2121

2121

11 2

1

ikkikk

ikkikk

kM

3232

3232

23 2

1kikkik

kikkik

ikM

aik

aik

e

eM

2

2

0

02

4

454321

1

0

B

AMMMMM

B

x

n1

n2

n3

M1 M2 M3

k1

k2

k3

xkeA 11

xkeB 11

xikeA 22

xikeB 22

TE mode

xikeA 22

xikeB 22

xkeA 33

xkeB 33

ba a2M5 = M1M4 M7 = M3

)(4

2 baxikeA

)(4

2 baxikeB

)(5

3 abaxkeA

)(5

3 abaxkeB

M6

bk

bk

e

eM

3

3

0

04

aik

aik

e

eM

4

4

0

06

5

57654321

1

1

B

AMMMMMMM

B

A

5

57654321

1

0

B

AMMMMMMM

B

clear;clf;lamda = 1.5; %umn1 = 1.5;n2 = 1.6;n3 = 1.5;k0 = 2*pi/lamda;dn = n2 - n3;N = 100000;neff = n3+dn/N:dn/N:n2-dn/N;beta = k0.*neff;k1 = (beta.^2-k0^2*n1^2).^.5;k2 = (k0^2*n2^2-beta.^2).^.5;k3 = (beta.^2-k0^2*n3^2).^.5;d = 5; %umb = 2; %umnm = 0;for m = 2:length(beta) M1(1,1) = (k1(m)+i*k2(m)); M1(1,2) = (k1(m)-i*k2(m)); M1(2,1) = (k1(m)-i*k2(m)); M1(2,2) = (k1(m)+i*k2(m)); M1 = M1./(2*k1(m)); M2(1,1) = exp(i*k2(m)*d); M2(2,1) = 0; M2(1,2) = 0; M2(2,2) = exp(-i*k2(m)*d); M3(1,1) = (k3(m)+i*k2(m)); M3(1,2) = (-k3(m)+i*k2(m)); M3(2,1) = (-k3(m)+i*k2(m)); M3(2,2) = (k3(m)+i*k2(m)); M3 = M3./(i*2*k2(m)); M4(1,1) = exp(k3(m)*b); M4(2,1) = 0; M4(1,2) = 0; M4(2,2) = exp(-k3(m)*b); M5 = M1; M6 = M2; M7 = M3; M = M1*M2*M3*M4*M5*M6*M7; M11(m) = M(1,1); I11(m) = abs(M11(m)); if I11(m)<1e-3 if I11(m)>I11(m-1) nm = nm +1; gneff(nm) = neff(m-1); else end else end endplot(neff, I11);zoom on;nmn = 1;ggneff(1) = gneff(1); for m = 2:nm if (gneff(m)-gneff(m-1))>1e-5 nmn = nmn+1; ggneff(nmn) = gneff(m); % effective index endend

%calculate model profilem = 2;betam = k0.*ggneff(m);k1m = (betam.^2-k0^2*n1^2).^.5;k2m = (k0^2*n2^2-betam.^2).^.5;k3m = (betam.^2-k0^2*n3^2).^.5; M1(1,1) = (k1m+i*k2m); M1(1,2) = (k1m-i*k2m); M1(2,1) = (k1m-i*k2m); M1(2,2) = (k1m+i*k2m); M1 = M1./(2*k1m); M2(1,1) = exp(i*k2m*d); M2(2,1) = 0; M2(1,2) = 0; M2(2,2) = exp(-i*k2m*d); M3(1,1) = (k3m+i*k2m); M3(1,2) = (-k3m+i*k2m); M3(2,1) = (-k3m+i*k2m); M3(2,2) = (k3m+i*k2m); M3 = M3./(i*2*k2m); M4(1,1) = exp(k3m*b); M4(2,1) = 0; M4(1,2) = 0; M4(2,2) = exp(-k3m*b); M5 = M1; M6 = M2; M7 = M3; M = M1*M2*M3*M4*M5*M6*M7;V1 = [0 1]';B1 = V1(2);V2 = M1^-1*V1;A2 = V2(1);B2 = V2(2);x1 = -10:0.001:0;y1 = B1.*exp(k1m.*x1);figure (2)plot(x1,y1);hold on;x2 = 0:0.001:d;y2 = A2.*exp(-i*k2m.*x2) + B2.*exp(i*k2m*x2);V3 = (M1*M2*M3)^-1*V1;A3 = V3(1)*exp(k3m*d);B3 = V3(2)*exp(-k3m*d); % = 0plot(x2,y2, 'r');x3 = d:0.001:d+b;y3 = A3.*exp(-k3m.*x3) + B3.*exp(k3m*x3);plot(x3,y3, 'b');V4 = (M1*M2*M3*M4*M5)^-1*V1;A4 = V4(1);B4 = V4(2); % = 0x4 = d+b:0.001:d+b+d;y4 = A4.*exp(-i*k2m.*(x4-d-b)) + B4.*exp(i*k2m.*(x4-d-b));plot(x4,y4,'r');V5 = (M1*M2*M3*M4*M5*M6*M7)^-1*V1;A5 = V5(1);B5 = 0; %V5(2); % = 0x5 = d+b+d:0.001:d+b+d+d;y5 = A5.*exp(-k3m.*(x5-d-b-d)) + B5.*exp(k3m.*(x5-d-b-d));plot(x5,y5,'b');hold off;zoom on;

Twowaveguide.m

M(1,1) = 0

1.5 1.51 1.52 1.53 1.54 1.55 1.56 1.57 1.58 1.59

-50

0

50

100

150

mode profile

-10 -5 0 5 10 15 20-1.5

-1

-0.5

0

0.5

1

1.5