Demo Optic Communication Lab

8/16/2019 Demo Optic Communication Lab

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SKEE3742 Optic Communication Lab

MEASUREMENT OF ATTENUATIONOF THE OPTICAL FIRE

!"" C#un Hian

K#ai$unni%a Sa&iman

Mo#ama& Fa#mi S#am%u&&in

Mo#ama& Ha$it# Ha$un'Ha%%an



INTRO(UCTION

• When using a optical fbre, some o the lightabsorbed by the glass inside the cable.

• The light coming out not strong as light

coming in• There are several actor:1) Distance o air gap between two connecting optical

fbre.

) The bending diameter o optical fbre.!) The source o light enter the optical fbre.

") The length o optical fbre.



PROLEM STATEMENT

• #ptical fbre is a medium to carryinormation.

• $ttenuation occur whentransmission o light through the

optical fbre.• %t will reduce the intensity o the

light.

• $ttenuation& '(log d

•



THE (ISTANCE OF AIR )APET*EEN OPTICAL FIERS

+-+%/+0T 1



O!ECTI+E

• To study the eect o air gaptoward the attenuation in optical

fber.• To e2amine the relationship

between the length o air gap

and attenuation in optical fber.• To determine the relationship

between re3uency and the

attenuation o optical fber.



-#4+D5+

1.+3uipment was set up as shown below.

.4onnect the a pair o 1 meter optical fber totransmitter and receiver.

!.6et a input re3uency with ((78.

".4onnect the end o each cable with (mm air gap.

9.#bserve and record the output at oscilloscope.

.epeat step 1'9 with increase the air gap until9mm with increment o 1mm.

;.epeat step 1' with a re3uency o .9<78 .



RESULT

F$",u"nc- . 2//H0

$ir =ap >mm)

?in>p'p)>?)

?out>p'p)>?)

$ttenuation>d)

( ;.@" ".@( ".

1 ;.A !.@( .!@ ;.A ."( 1(.!;

! ;.@" 1.( 1.!(

" ;.@" (.@( 1A.@!

9 ;.@" (.( .!!



RESULT

F$",u"nc- . 21H0

$ir =ap>mm)

?in>p'p)>?)

?out>p'p)>?)

$ttenuation>d)

( ;.@( ;.( (.

1 ;.@( 9.@( .9; ;.@( !.( ;.;!

! ;.@( 1.@( 1.;"

" ;.@( 1.( 1.

9 ;.@( (.@( 1A.;@



( 1 ! " 9 (

9

1(

19

(

9

Att"nuation b"t""n 5$",u"nc-

(( 78.9<78

Ai$ )ap 6mm

Att"nuation 6&



CONCLUSION

• The bigger the air gap the higherthe signal loss.

•

The e2istence small air gapcontribute to huge o attenuation

• The higher re3uency will give

less attenuation o optical fber.



THE EN(IN) (IAMETEROF OPTICAL FIER

+-+%/+0T



To e2amine therelationship between thelength and attenuation in

the optical fber

#B+4T%?+



E8PERIMENT PROCE(URE9

1.The e2periment is set upby connecting the inputand output > transmitter Creceiver ) to the E'A9((1

trainer..The bending diameter is

varied rom 1(mm, (mm,!(mm, "(mm, and 9(mm.

!.The input and outputreading are ta<en rom theoscilloscope.

".$ttenuation is calculatedb the ormula



RESULT

F$",u"nc- . 21 H0

Diameter>mm)

?in>p'p)>m?)

?out>p'p)>m?)

$ttenuation>d)

1( "".@ 1( ';.19

( "".( 1!" 'A.9"!( "9. 1" '1(.11

"( "".@ 19" '1(.;

9( "".@ 19 '1(.@"



1( ( !( "( 9(

'1

'1(

'@

'

'"

'

(

=raph o $ttenuation>d) against ending Diameter

6mallest bending diameter, 7ighest$ttenuation >d)

$ttenuation higher as the attenuation valuebecomes more positive



CONCLUSION

In t#i% ":p"$im"nt;Mac$o "n&in< Lo%%$"%u=t #a% b""n

%#on1

A% =i<#t t$a>"= in t#"%t$ai<#t =i<#t; t#"

po"$ =o%%"% i%una>oi&ab=" #"nb"n&in< o5 t#"optica= ?b"$ occu$%1



THE SOURCE OF LI)HTINTO OPTICAL FIER

+-+%/+0T !



•

To measure the attenuation inoptical fbre communicationby varying the light sources.

O!ECTI+E



PROCE(URE91.The e2periment was setup by varying light

sources eg. headlamp, E+D, Easer, andphone Fashlight.

.$ light source is connected to the input

transmitter by optical fbre cable and thenconnected to the output receiver in E'A9((1 trainer.

!.The optical fbre cable is f2ed at 1m only

or all light sources e2periment in this part.".The voltage input and output reading are

recorded rom the digital oscilloscope.9.The results were analysed.

.$ttenuation is calculated by the ormula



RESULT

F$",u"nc- . 21H0

Eight 6ource?in>p'p)

>m?)?out>p'p)

>m?)$ttenuation

>d)

E+D ";. "1. 1.1(

-hone Glash "." "(.@ 1.17eadlamp "9. !9. .9

Easer "@.( "9. (."9



• $ laser shows the smallest attenuation which (."9d• $ headlamp shows the highest attenuation which .9d• $ E+D is better perormance than phone Fashlight due to the lower

attenuation which 1.1H1.1 d

E+D -hone Glash 7eadlamp Easer(

(.9

1

1.9

.9

=raph o $ttenuation>d) vs. Eight 6ources$ttenuation>d)

Eight 6ourc



CONCLUSION•

The longer the distance o a lightsource travels, the greater theperormance o optical fbrecommunication system.

• $ dierent type o light sourcesgive a dierent perormance.

• The higher the attenuation, the

shorter the distance o a lightsource travels.

• -ractically, the laser use or a

longer distance communication



THE LEN)TH OF OPTICAL FIER

+-+%/+0T "



O!ECTI+E

• To e2amine the relationshipbetween the length and

attenuation in the optical fbre• To fnd the eect o re3uency on

the attenuation



PROCE(URE

• The e2periment was set up using module E'A9((1trainer

• The transmitter input and receiver output wasconnected to the oscilloscope

• $ 1m optical fber was connected rom transmitterto receiver.

• $nalog signal was set as the input signal

• Gre3uency was varied to 1<78, 1.;9<78, .9<78

• The signals on oscilloscope was observed andrecorded

• 6tep 1 to step 9 were repeated by replacing 1moptical fber with !m and 9m optical fbers.



RESULT

L"n<t# o5 Optica= Fib"$ . @ m"t"$

Gre3uency><78)

?in >p'p)>m?)

?out>p'p) >m?)

$ttenuation>d)

1 .(( 1"." !. '".1"

1.;9 !"." !." (.921/ "1.; ". /1@B



RESULT

L"n<t# o5 Optica= Fib"$ . 3 m"t"$

Gre3uency><78)

?in >p'p)>m?)

?out>p'p) >m?)

$ttenuation>d)

1 .(( 1"." (. '.A"

1.;9 !9. @.@ 1.;"21/ "." "".@ /13@



RESULT

L"n<t# o5 Optica= Fib"$ . m"t"$

Gre3uency><78)

?in >p'p)>m?)

?out>p'p)>m?)

$ttenuation>d)

1 .(( ".( ." '(.@!

1.;9 !"." .1 !.@"21/ ";. !@." @17B



$ttenuation vs Eength o #pticalGiber

( 1 ! " 9

'9

'"

'!

'

'1

(1

!

"

9

1.((<7I

1.;9<7I

.9(<78

L"n<t# o5 Optica= Fib$" 6m"t"$

Att"nuation6&



CONCLUSION

• The longer the length o opticalfber, the higher theattenuation o optical fber.

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Demo Optic Communication Lab