Lecture 6. Components

7/25/2019 Lecture 6. Components

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6. Opticalcomponents

Optical CommunicationSystems

andNetworks

Lecture 6: Optical Components 1/

Optical Communication Systems and Networks


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BIBLIOGRAPHY

Optical Networks. A practical perspectiveRajiv Ramaswami, Kumar N. Sivarajan, Chapter 3, pp. 107-223, Ed.or!an"kau#mann.$nd Edition, $%%$.

E&ternal electro"optic modulators'.A.A. Sale( y .C. )eic(. Fundamentals of Photonics, Chapter18, Ed.*iley.+terscience.

. Capamany, -. . -raile"el/e0, . art1, 2Dispositivos deComunicaciones pticas,3C(apter 6, Ed. S1ntesis

Optical passive components4 couplers,com5iners,

isolators, lters, multiple&ers, 7


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. Capamany, -. . -raile"el/e0, . art1, 2Dispositivos deComunicaciones pticas,3C(apter $, Ed. S1ntesis


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Introduction to optical networks

Unidirectional transmission

Bidirectional transmission)(e same #i5er used to carry out tra##ic in 5ot( propa!ation directions

Advantages:+t is ac(ieved an optimi0ation o# optical #i5er 5andwidt( and costsavin!s outside plant

isadvantages:a9 Special components :circulator9 are needed #or separatin!t(e transmission directions

59 ost E;-As (ave internal insulators t(at prevent5idirectional transmission c9Crosstalk #rom nonlinear e##ectsd9 Comple& implementation o# restoration and protection sc(emes

Settin! up li!t(pat(s alon! #i5er optic links and nodes supportin!tra##ic #rom a varietyo# client layer4 A), +, ... +n t(e optical layer, comprises4

Optical transmission medium O drop multiple&er #or insertin! or removin!

optical c(annels

)ema

64Redes*;


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Lecture 6: Optical Components ?/


O@C, optical Crossconnect


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Optical transmission medium

Parameters toconsider whenchoosing anoptical fiber

o Core and claddin! diameters :m9o Attenuation coe##icient :d'>km9o ;ispersion coe##icient ; :ps>kmBnm9o ;i##erential ;ispersion coe##icient:ps>km.nm$9o ; parameter :ps>km>$9o inimum dispersion wavelen!t( :m9

o Cuto## wavelen!t(:m9o Nonlinear re#ractive inde&o odal #ield diameter > e##ective area :m9

'and descriptors de#ined 5y +)D to operate in minimum lossspectral re!ion

Ban escriptor !pectral range

O Ori!ina $6% 86%

E E&tended 86% ?6%

S S(ort ?6% F8%

C Conventional F8% F6F

<


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D Dltra"lon! 6$F " 6GF


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!tandard !ingle $ode %i&er' SSMF

H Represents IFJ o# installed outside plant : %% million km9H Standardi0ed 5y +)D"L.6F$ recommendationH Dsed #or transmission wit(in t(e spectral ran!e $6% " 6GF nm,e&cept E

and S 5ands

H resents (i!( dispersion 5etween F8% " 6GF nm spectralre!ion

+t re=uires dispersion compensation #or lon! distances

ain applications4 Operation at 8%nm in

CA)M and ANnetworks

Operation at FF%nmover lon! distances

)ypical ;ispersion pro#ile

CN

%


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8% nm FF% nm

)ema

64Redes*;

ispersion"


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Lecture 6: Optical Components 6/53


ispersion !*i+ted %i&er' DSFH 'y a !eometric modi#ication o# t(e re#ractive

inde& pro#ile t(e minimum dispersion wavelen!t(is s(i#ted #rom $nd to 8rd communicationswindow

H


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,on-.ero ispersion %i&er' NZDSFH


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NQ;S- NQ;S-"


)ema

64Redes*;

O C / 53


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Lecture 6: Optical Components 8/ 53

Optical line terminal e/uipment' OL0

Orepeaters9 andoptical ampli#iers

S;

Optical ,ode: OL0 +unction

1

router+.

router+

Clientprotocols

standard

2

3

O(4(O

:transponder9

mu&

demu&

OCS

12

3

O5!

Si!nals Si!nals


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Si!nalsmana!ed inelectricaldomain

Si!nalsmana!ed in

opticaldomain


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64Redes*;

L t 6 O ti l C t 9/


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O)< presents adaptation #unctions4 t(e wavelen!t(conversion accordin! to standards set 5y t(e +nternational)elecommunications Dnion :+)D9

)ransponders may add additional over(ead #or purposes o#network

mana!ement)(e adaptation #unction is typically done t(rou!( an optical"to"electrical"to" optical :O>E>O9 conversion

H t(e adaptation can 5e ena5led only in t(e incomin! direction

)(e si!nal comin! out o# a transponder is multiple&ed wit(ot(er si!nals at di##erent wavelen!t(s usin! a wavelen!t(multiple&er

+t e&ists tec(nolo!ical options to implement mu&>demu&4 %a&r6-Perot +ilters,arra6ed waveguide gratings, dielectric t*in-+ilm +ilters, or+i&er Bragg gratings


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O


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Optical $ultiple7ers

)(e #unction o# t(e multiple&er is to couple two or morewavelen!t(s in t(e same optical #i5er

:the demultiple"er is responsible for performing the inerseoperation, to separate the

arious waelengths comprising the #$% signal from anoptical fiber9

ultiple&erre/uirements4

H


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)ec(nolo!ical options considered #or t(e implementation o#multiple&ers are considerin! in t(e #ollowin! devices.




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%a&r6 8 Perot +ilters

- #ilter is a dielectric resonant cavity :etalon9, #ormed 5y two(i!(ly re#lective

mirrors placed parallel to eac( ot(er.

+t (as 5een used #or *; applications alt(ou!( t(ere are 5etter#ilters nowadays

&in

$irror1

:t,r9

l

$irror2

:t$,r$9

n

&out

T T$ T

HTTTCT$TC

T$T

HT8T

ti:transmission

coefficient (field)

ri:transmission

coefficient (field)

l: cait! length

n' refractieinde" of thecait!

)ema

64Redes*;

)(e electric #ield at t(e output is t(e sum o# successive


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)(e electric #ield at t(e output is t(e sum o# successivetransmitted #ields4

TTTT P TTT B TCT$THT T T TCT$T

H$T T T TC$T$

$T H?T T T U




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Considerin! t(e associated periodic)rans#er-unction ):f94

$

RP%.$

RP%.F

T T P

TT

TT

T

TT

H T H

T $P

H T $ ?TTTTT$:

T9TTT

RP%.I

*(ere RPVriV$, A takes into accountintracavity losses :de#ined in power9

and it is de#ined as4 AP C":R)9

)(e periode is de#ined t(rou!( t(eparameter -SRor free spectral range'

T

NormalizedTransferfunctiion

T(f)

P


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P$TT %

% $ 8 ?

Normalized frequency f/FSR




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)(ere are several parameters to evaluate t(e per#ormance or =uality o# a -"#ilter:assumin! mirrors re#lectivity is near R94

1# %9H$4 -ull"widt( at (al#ma&imum

TTT T P$TTTT

arcsi

n

H

T

$T

-*

>$

2#

%inesse'F

5*annelselection

Cnn

'

-SR

TT

TT P

T T

T

W

H T

C(annels5and


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-SR

' 5andwidt( #re=uency

'5andwidt(

#re=uency

+t must 5e satis#ied B %!R, ot(erwise crosstalkX




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%ilters &ased on Bragg gratings

)(ese devices are 5ased on t(e e##ect 'ra!! e##ect actin! asselective wavelen!t(

re#lective mirrors )(ey are 5uilt 5y insertin! a di##raction !ratin! in t(e #i5er :'ra!!

!ratin!9H A pattern is written in t(e core o# t(e accordin! to a presta5lis(edperiodic variation o# t(e re#ractive inde&

H *(en li!(t propa!ates t(rou!( t(is pattern, t(e wavelen!t( satis#yin!'ra!! condition

re#lects w(ile t(e remainin! wavelen!t(s continue t(eirpropa!ation alon! t(e 5er

n(z)

n+n n0

'Re#ra

c pro#il 0ransmitted


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ctiveinde&

pro#ile

'

andRe+lectedwavelen!t(

n-n

%

Braggcondition

B ;2n


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p p


%ilters &ased on Bragg gratings

)(ey are usually com5ined wit( optical circulators to operate asoptical add"drop

multiple&ers

Alt(ou!( insertion loss is ne!li!i5le, it increases up to 8d' w(en t(eyare con#i!ured as OA; due to t(e inclusion

o# circulators C(annel spacin! o# %% L0 and F% are ac(ieved, keepin! a lowadjacent

c(annel crosstalk

Ot(er advanta!es4

Easy couplin! to ot(er #i5ers +nsensitivity to polari0ation loss Reduced cost Active control o# temperature not re=uired

+n t(e desi!n o# an OA;, it is important to consider t(e pass"5and narrowin! a#ter propa!atin! alon! a OA; cascaded

sta!es :crosstalk and losses9

OA; device manipulates only t(e e&tracted si!nals wit(out


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OA; device manipulates only t(e e&tracted si!nals wit(outa##ectin! t(ose

w(ic( traversin! t(e node, t(ere5y reducin! undesira5le e##ects.




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p p

Dropping a channel in a WDM system

wavelen!

t(

'ra!!!ratin!tuned at8

wavelen!t(

)(e reYection spectrum is o5tained as t(e-ourier trans#orm

o# t(e inde&distri5ution

)(e 5andwidt( is inversely proportional tot(e len!t( o# t(e!ratin! :a #ew millimeters lon! provides a5andwidt( nm9

wavelen!t(

wavelen!t(

'ra!!!ratin!tuned at8

wavelen!t(

wavelen!t(


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wavelen!t(

dd!Drop function "ased on#ragg fi"er gratings

(lso a$aila"le a coupler-"asedsolution replacing %nd cirtulator)

wavelen!t(




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0*in %ilm milticavit6 %ilters

A multilayer dielectric t(in #ilm #ilters :)--9 is 5ased on a -a5ry"erotinter#erometer consistin!o# multiple cavities surrounded 5y multiple re#lective dielectric t(in #ilm layers

)(is device acts as a 5andpass #ilter w(ere a particular wavelen!t( passest(rou!( and t(erest are re#lected is determined 5y t(e len!t( o# eac( cavity

)(e lter response is determined 5y t(e num5er o# cavities4 as t(enum5er increases t(e top o# t(e pass5and 5ecomes #latter and t(e skirts5ecome steeper

Cavity

input;ielectric layers actin! asselctive wavelen!t( mirrors

Cavity $ Llass Cavity 8


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Cavitysu5strate

Cavity 8




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53


Implementation as a multiple7er ( demultiple7er:

resence o# lenses wit( !raded re#ractive inde& #or con#inin!and directin! at a certain an!le t(e si!nal to t(e ne&t #ilter

Eac( #ilter allows a specic ran!e o# wavelen!t( o# li!(t to pass

t(rou!( to re#lectt(e rest to t(e ne&t #ilter in t(e cascade arran!ement

$ain +eatures:

E##icient con#i!uration4 access only to c(annels to 5e removed andinserted wit(out a##ectin! t(e rest o# t(e wavelen!t(s passin!

t(rou!( -lat ass5ands and very steep skirts Sta5ility to temperature variations


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p y :savin!9




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53


Arra6ed waveguide gratings' A9Gs

Arrayed

wave!uides

coupler coupler

A*Loperatin! asademultiple&er

A*L is a !enerali0ation o# t(eac("Qe(nder inter#erometer

+t consist o# two couplers interconnected 5y an array o# wave!uides

)wo copies o# t(e same si!nal 5ut s*i+ted in p*ase 5y di##erent amounts

are added to!et(er

A*Ls can 5e used as an n wavelen!t( multiple7ers4 an n"input, "


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! poutput device w(ere

t(e n inputs are si!nals at di##erent wavelen!t(s t(at are com5ined ontot(e sin!le output

emultiple7ing is per#ormed 5y t(e inverse o# t(is #unction : nwavelen!t(s9




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Optical 5rossconnects' O>5

B A A BA A A A

'$ '

8 ' ?

1'

2

'

3

' ?2

3

-i5er A ? -i5er A

'

' '

;emultiple&ers

ultiple&ers

A B B A

B B B B1 2 3 ? 2 1 '

2

'3

' ?

3

-i5er ' ? -i5er '


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-i&ed Optical crossconnect. Static wavelent!( switc( routessi!nals#rom an input port ro an output port on 5asis a predesi!nedassi!nmet




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Introduction to optical components

assive optical devices act on si!nals propa!atin! t(rou!( t(em.Amon! t(e various #unctions t(ey per#orm are not included t(e!eneration, transmission, ampli#ication and optical detection

atri& #ormalism is used #or descri5in! polari0ation p(enomena andapplications. )(ere are

several met(odes4

-or devices w(ic( are not a##ected 5y t(e polari0ation state o# t(e

si!nal :not alter t(e state o# polari0ation wit( respect to t(e si!nalinput94

Scattein! mati"' relates out!oin! #ields wit( incomin!electrical #ields

#ansfe mati"4 relates incomin! and out!oin! #ields o# an evennum5er o# ports on t(e le#t side o# t(e optical component wit( t(e

incomin! and out!oin! #ields o# an even num5er o# ports on itsri!(t

$ones $atri7 descri5es t(e c(an!e or modi#ication o# t(e opticalsi!nal polari0ation state w(en an optical si!nal !oes t(rou!( anoptical device

+t is used in polari0ers, polari0ation rotators, wave

retarders, isolators, orpolari0ation splitters and com5iners

+t is very common t(e use o# parameters e&pressed in d' #rom


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+t is very common t(e use o# parameters e&pressed in d' #rommanu#acturers datas(eets w(ic( provide in#ormation a5out t(e powerdistri5ution amon! di##erent ports


Lecture 6: Optical Components $$/


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Optical pasive5om onents:


#i5er$

#i5er

4vanescent

+ieldcoupling

S%stem o+

coupled lineardiffeentiale&uations

dE&'jEc E

dz

dE%

& &

'jE

&% %

c E& dz

$

% % %& &

L cij = coupling coefficient

E&(z)

cos(cz)

jsen(cz )E&(0)

Po'e definition

P(z) E (z) P(0)(&')

E% (

z)

jsen(cz)

cos(cz )E%

(0)

& P (z)

&

E (z)

&

%

%

Lecture 6: Optical Components $8/


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Optical pasive5om onents:


& P(0)E&(z) &'

j

E&(0)

% % &

Ez

&

E

% ( ) j ' % (0) !"ere sen$(cL) is t"e coupling ratio


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*ncoming energy from M% input,a$eguides is distri"uted into N%

output ,a$eguides

CZC:TT9

:%9

Optical coupler response

P&(0)

P%(0)

P&(L)PP%(L)P.

OPTICAL COUPLER

M=2N=2Z$

:TT

9

$ :%9


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% % $ 8 ?

Normalized distance


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There are different technological options to implement combiners.The most usual are:

-Based on optical fibers

- Fusion

- Polishing

-Based on integrated optics

- Deposition

- Ionic-exchange

Operationprinciple4

evanescent #ield o modal

inter#erencecouplin!



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Optical pasive5omponents:

5OUPL4R!(5O$BI

,4R!P

in (1

Port 1

Port 2

Pin (2(negligible ideally)

Pout (4

Port

Port !

Pout (3

Sc"ematic

coupler 2#2

(nsetion )oss* loss e&perimented 5yt(e si!nal w(en it propa!ates accordin!to a particular con#i!urarion input"outputports

+"cess )oss* ratio o# total power atall outputports wit( respect to t(e input power.

P

P

L L (d#)&0log&

LE(d#) &0log()&0

log/P

P0

$ i

.

Couplin! paamete* providesin#ormation a5out (ow power is distri5uted amon! outputports

P

o

P

o

P

o

P

Diectivit% represents t(e power#raction at t(e input port w(ic( is


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#raction at t(e input port w(ic( is5ack"propa!ated to ot(er input ports

P

P.

PP.%(d#)&0log

%

P&




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5OUPL4R!(5O$BI

,4R!

Directional Coupler M x N Coupler N x N

+nputs :i, i[9Outputs :k, k[9

Inputs ! outputs

x! ("( coupler built fromlog2(

stages of elemental 2"2couplers

Input po"er is distributed e#uall$ through all output ports %excess loss negligible&

Output power$ %nput power&N ' e#cess loss

L (d#)

'&0log

P

)*P)dis)&

P$ i %ii 1 (d#& ) '&0 logi1

PPi

'niformit$ 'L

ma2'L$ min i

& ;i t i5 ti


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L$

Pij

& ;istri5utionloss

LE i(d#)&0

logi'&0log j&

Pi

Ldi

(d#)'&0log&




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Optical pasive 5omponents:$UL0IPL4>4R!(4$UL0IPL4>4R!

*+%P*,-O.

1

2

12

1

2

/,*+%P*,-O.

1

2

ultiple&>demultiple& #unctions can 5e also per#ormed 5y #ilter tec(nolo!y:-"+abr!-Perot +ilters, A*L"rra!ed #aeguide ratings, )--"hin +ilmmultila!er +ilters9


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Polari=ers:

Passive components acting on polari=ationstate

Allows t(e propa!ation o# t(e linear polari0ation component o# t(eelectric #ield ali!ned in t(e direction o# its transmittin! a&is, 5lockin!t(e propa!ation o# t(e ort(o!onal component.

0ec*nological options:

. A5sorption or selective loss$. Selective re#lection in isotropic materials

8. Selective re#raction in 5ire#rin!ent materials

+n practice, t(e ort(o!onal polari0ation is not completely suppressedand t(e passin!polari0ation component :parallel to t(e optical a&is9 su##ers losses,unlike an idealpolari0er.

Operatingparameters:

TTVV

(nsetion)oss4 +

"

tinctati

TTVV *


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TT TTP %TTT%

TTT T TT P %TTTC%

TTT VV

TTTVV

TTT\

TT

\

*TTT

VV




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9averetarder:

+ntroduces a relative p(ase s(i#t :p(ase retardation9 5etweent(e (ori0ontal and vertical states o# t(e electric #ield

)(ey are implemented 5y usin! 5ulk optics :anisotropic media94

5ire#rin!ent #ilms wit( a t(ikness d wit( a particular re#ractive inde&nh #or (ori0ontal polari0ation :slow a&is9, and a di##erent re#ractiveinde& nv #or vertical polari0ation :#ast a&is9. )(en 4

$ZT22222222222] P

Z

]T^ H TT

TTTTTTTZTTTTTTT P TZT$

$

@uarter wave retarder

*(en ;(2' t(e initial linearly polari0ed si!nal :at ?F_ wit(respect to & a&es9 is trans#ormed to a le#t"(and circularpolari0ation

Hal+-wave retarder


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9averetarder:

+ntroduces a relative p(ase s(i#t :p(ase retardation9 5etweent(e (ori0ontal and vertical states o# t(e electric #ield

)(ey are implemented 5y usin! 5ulk optics :anisotropic media94

5ire#rin!ent #ilms wit( a t(ikness d wit( a particular re#ractive inde&nh #or (ori0ontal polari0ation :slow a&is9, and a di##erent re#ractiveinde& nv #or vertical polari0ation :#ast a&is9. )(en 4

$ZT22222222222] P

Z

]T^ H TT

TTTTTTTZTTTTTTT P TZT$

$

polarizer

*

retarder

polarizer

% 3 $3 83 ?3

/etardation,

.ransmittance

plication* (ntensit%contol


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wae retarder 2 polarierscrossed config.




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Passive components acting on polari=ation state

Polari=ation Rotators:

A polari0ation rotator produces a rotation o# t(e polari0ationplane o# a linearly polari0ed wave 5y a #i&ed an!le 3 , maintainin!t(e linearly polari0ed property.

+t is re=uired materials in w(ic( a ma!netic #ield - produces t(erotation o# t(e polari0ation direction o# linearly polari0ed wave. )(isproperty is called Faada% effect

P

TTT

w(ere 4 is t(e Merdet constant and its value depends on t(e material used:n, re#ractiveinde& andma!neto"optical rotation coe#cient9 and wavelen!t(4

T P

H

TTT

2

$aterials wit*%arada6 e++ect:


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)er5ium !allium !arnet :)LL9, ter5iumaluminum !arnet :)5AlL9, and yttrium iron!arnet :`+L9.

'ismut( !arnets :Ld'iLand )5'i+L9 are used in

FF% nm

olari0ation rotation in a madium e&(i5itin! t(e +arada! effect


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Optical Isolator:

)ransmits li!t( in only one direction, preventin! re#lected li!(t#rom returnin! 5ack to t(e source

Pin

Pout

Port 1 Port 2

Pout

(ideally 0)P

in

/iagram of an Optical isolator

Insertion Loss, considers t(e powerloss w(enli!(t propa!ation is in t(e direction:Z $9 4

%solation ratio( pro)ides the ratio bet"een the

po"er transmitted through port * "hen optical

po"er is introduced in port +:

3 P P 3 3

in(&)

in(%)

Li (d#) &0log&0 P

$(d#)&0log&0P ou t(%) out(&)


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Optical Isolator:

Transmitted

!ae

+,-

Polarizer #

Farada Rotator

* +,-

Polarizer .

Reflected

!ae

+,- Polarizer #

B

Farada Rotator

*$ncident

!ae

* +,-0- Polarizer .

* #locing

Btransmitted

signal



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OP0I5AL

A004,UA0OR!

Reduce t(e power level att(eir

entrance

Allow to adjust properlypower levels at t(e opticaldevices input ports #or acorrect per#ormance

Can provide a #i&ed orvaria5le attenuation

-i&edattenuator

Maria5leattenuator

-i&ed>varia5leattenuators 5ytransversal orlon!itudinal

desplacement


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OP0I5AL

5IR5ULA0OR!

Circulators allow addin! and droppin! optical c(annels in a *; si!nal,processin! optical (eaders and selective optical processin! #unctionsw(en t(ey are com5ined wit( ot(er optical devices.

$

he signal in5ected into the port 1 goesdirectl! to the port 2. #hen a signal isintroduced in 2, it e"its through the port3. nd a signal comes through 1 when ithas been preiousl! introduced in port 3.

8

*avelen!t(s att(e input $8?

dding or dropping channels in WDM systems

'r

;ropped$

*avelen!t(s at t(e output $8?wavelen!t(48 8


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8



4>04R,AL $OULA0OR!


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4>04R,AL $OULA0OR!

Optical sources directly modulated at (i!( #re=uencies in systems5ased on intensity modulation :+9 can introduce c(irp w(en

semiconductor laser diodes are used as transmitter, increasin! t(edispersion e##ects, and t(en, limitin! t(e ma&imum 5it rate.

C* emission +n#ormation :electrical si!nal9

;iode04R,AL $OULA0IO,

A#ter 5iasin! semiconductor lasers 5y a constant current, t(econtinuous wave emission :C*9 is injected into an e&ternal device:e&ternal modulator9 w(ic( superimposes a copy o# t(e electricalin#ormation si!nal, providin! t(e optical si!nal modulated at t(e

output .

)(is will eliminate or reduce t(e c(irp tone!li!i5le values .


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4>04R,AL $OULA0OR!

)(ere are two main tec(ni=ues to implement e&ternalmodulators wit( #eatures suc( as #ast response,simplicity and compacticity re=uired in optical systems4

1# 4lectro-optic $odulators+ntensity and p(ase modulation are ac(ieved'ased on #erro"electric crystals like lit(iumnio5ate :


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4>04R,AL $OULA0OR!: 4lectro-optice++ect

EO e##ect is responsi5le #or t(e re#ractive inde& c(an!e in electro"optic materials 5y applyin! an e&ternal #ield :ockels e##ect9.

E&ternal modulators take advanta!e o# t(is e##ect to modulate t(eoptical carrier in

p(ase or intensity

Crystals used in modulators are anisotropic, in w(ic( re#ractiveinde& depends on t(e polari0ation direction o# t(e electric #ield:optical si!nal9

)o produce an intense e##ect, t(e access to r88 coe##icient, t(e

!reatest element in t(e electro"optic tensor, is re=uired. )(is isac(ieved w(en t(e electric #ield polari0ation is parallel to t(e cristal[soptical a&is4

n(E) n0& -%

0 --

n%P re#ractive inde& in a5sence o# electric #ield

n r E

n:E9P re#ractive inde& w(en electric #ieldis applied r88 electro"optic e##ectE Applied electric #ield component accordin! to t(e optical a&is


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E Applied electric #ield component accordin! to t(e optical a&is




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Optical a!is (c)

y

,i()$,oie#p34n&c5

6

,()$, e#p(34n(,)&c)i oi

, applied

7

# *iNbO! crystal:anisotropic

cr!stal9

n E n0 & -

With typical values of LiNbO3

% n01 1

r 30

pm/4n r E


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121 30



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p y


4>04R,AL $OULA0OR!: 4lectro-optic


79/105


,in()

6

,out()

odulated

wa8e

%

d

.esponse

%ncident wa8e

in C9% 4 4

4

) 4

The incident "a)e

must be polari,ed

4

d

r nL

4alues in

the range

2-6 4 0

0


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81/105


66

0RA,!4R!AL5O,%IGURA

0IO,

6

LO,GI0UI

,AL

5O,%IGURA0I

O,


82/105

O,




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Applications: 4lectro-optic modulator +orintensit6 modulation

"Polari=ation con+iguration#

Output polari7er

ptical intensit$ modulator

based on Pocels cell

bet"een crossed polari,ers

%nput polari7erriented at 6 de!rees

wit(respect to t(eoptical a"is

M

C,%

ptical

Transmittance

%,F

%,%

t

.ransmittance243

M5ias . 4oltage,

t


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Applications: 4lectro optic modulator +or


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Applications: 4lectro-optic modulator +orintensit6 modulation

"Inter+erometer con+iguration#

Intensit$ modulator based on

ach-/ehnder Interferometer

I$ L0

M

;iodes

'L0M>$

R. 8 33' EFD

;iode


92/105


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Return to =ero sc*emes

RQ pulse o# t(ree duty cycles #or a 5it secuence4 %%%

% % % %

R. 8 C


94/105




95/105

$AI, OP0I5AL !9I05HI,G045H,OLOGI4!

Bulk opto-mec*anical switc*es

$icro-electro-mec*anical "$4$s#switc*es

Bu&&le-&ased waveguide switc*es

4lectro-optical switc*es 0*ermo-optic switc*es


96/105



OP0I5AL


97/105

OP0I5AL5O$PO,4,0!:

$icro-electro-mec*anical

switc* "$4$#


98/105

8; ES4 steerin! mirrors allow switc(in! in 8;. +t is o5tained adrastically increase o# t(e num5er o# ports, providin! more compactdevices :#rom $F6 to over %%% ports9

Advantages: #ast response, (i!( inte!ration and num5er o# ports



OP0I5AL


99/105

OP0I5AL5O$PO,4,0!:Bu&&le-&ased

waveguide switc*

Planarwavegui

deswitc*

wave!uides

Re#lected5eam

"switc*ing#

'u55le

No 5u55le

-luid c(annels


100/105

wave!uide to t(e desired output port



OP0I5AL


101/105

OP0I5AL5O$PO,4,0!:

!witc* &ased on integrated $ac*-.e*nder

inter+erometers"4lectro-optic

control#

Planar

waveguide

switc*

wave!uides

No5u55le

Molta!e on"switc*ing#


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isadvantages: Dsually (ave a relatively (i!( loss and ;

Documents

Lecture 6. Components