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INTERNATIONAL TELECOMMUNICATION UNION

ITU-T G.652TELECOMMUNICATIONSTANDARDIZATION SECTOROF ITU

(04/97)

SERIES G: TRANSMISSION SYSTEMS AND MEDIA,DIGITAL SYSTEMS AND NETWORKSTra !"#!!#$ "%a ' ara' %r#! #'! * O+ #'a -#.r% 'a. %!

Characteristics of a single-mode optical fibrecable

ITU T R%'$""% &a #$ G 123( r%5#$6! CCITT R%'$""% &a #$ )

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ITU T G SERIES RECOMMENDATIONS

TRAN !I I"N # T$! AN% !$%IA& %IGITA' # T$! AN% N$T("R)

For further details, please refer to ITU-T List of Recommendations.

INTERNATIONAL TELE 8ONE CONNECTIONS AND CIRCUITS G 00*G 99INTERNATIONAL ANALOGUE CARRIER SYSTEM

GENERAL C8ARACTERISTICS COMMON TO ALL ANALOGUE CARRIERTRANSMISSION SYSTEMS

G 300*G 399

INDI IDUAL C8ARACTERISTICS OF INTERNATIONAL CARRIER TELE 8ONESYSTEMS ON METALLIC LINES

G ;00*G ;99

GENERAL C8ARACTERISTICS OF INTERNATIONAL CARRIER TELE 8ONESYSTEMS ON RADIO RELAY OR SATELLITE LINKS AND INTERCONNECTIONWIT8 METALLIC LINES

G 400*G 449

COORDINATION OF RADIOTELE 8ONY AND LINE TELE 8ONY G 420*G 499TRANSMISSION MEDIA CHARACTERISTICS

G% %ra G 100*G 109S ""% r#' 'a. % +a#r! G 1 0*G 1 9La & '$a

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ITU-T RECOMMENDATION G.652

CHARACTERISTICS OF A SINGLE-MODE OPTICAL FIBRE CABLE

Summary

This Recommendation covers the geometrical and transmissive properties of single-mode opticalfibres and cables whose dispersion and cut-off are not shifted from the 1310 nm wavelength region.Definitions and test methods are contained in a separate Recommendation G.6 0.

Sourc

!T"-T Recommendation G.6 # was revised b$ !T"-T %tud$ Group 1 &1''(-#000) and was

approved under the *T%+ Resolution ,o. 1 procedure on the th of pril 1''(.

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/ R * RD

!T" &!nternational Telecommunication "nion) is the "nited ,ations %peciali2ed genc$ in the field of telecommunications. The !T" Telecommunication %tandardi2ation %ector &!T"-T) is a permanent organ of the!T". The !T"-T is responsible for stud$ing technical operating and tariff 4uestions and issuingRecommendations on them with a view to standardi2ing telecommunications on a worldwide basis.

The *orld Telecommunication %tandardi2ation +onference &*T%+) which meets ever$ four $ears establishesthe topics for stud$ b$ the !T"-T %tud$ Groups which in their turn produce Recommendations on thesetopics.

The approval of Recommendations b$ the 5embers of the !T"-T is covered b$ the procedure laid down in*T%+ Resolution ,o. 1.

!n some areas of information technolog$ which fall within !T"-T s purview the necessar$ standards are prepared on a collaborative basis with !% and ! +.

, T

!n this Recommendation the e7pression 8 dministration8 is used for conciseness to indicate both atelecommunication administration and a recogni2ed operating agenc$.

!,T 99 +T" 9 :R : RT; R!Ghad not received notice of intellectual propert$ protected b$ patents which ma$ be re4uired to implement this Recommendation.

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CONTENTS

Pa,

1 %cope................................................................................................................................................................................................................................................................1

# References........................................................................................................................................................................................................................................................1

3 Terminolog$......................................................................................................................................................................................................................................................#

@ bbreviations....................................................................................................................................................................................................................................................#

/ibre characteristics..........................................................................................................................................................................................................................................#

.1 5ode field diameter..........................................................................................................................................................................................................................................#

.# +ladding diameter.............................................................................................................................................................................................................................................#

.3 5ode field concentricit$ error..........................................................................................................................................................................................................................#

.@ ,on-circularit$..................................................................................................................................................................................................................................................3

.@.1 5ode field non-circularit$......................................................................................................................................................................................................3

.@.# +ladding non-circularit$.........................................................................................................................................................................................................3

. +ut-off wavelength...........................................................................................................................................................................................................................................3

.6 1 0 nm loss performance................................................................................................................................................................................................................................@

.( 5aterial properties of the fibre....................................................................................

.....................................................................................................................................@

R comm !"a#$o! G.652 %&'()*+ $$$

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.(.1 /ibre materials........................................................................................................................................................................................................................@

.(.# :rotective materials................................................................................................................................................................................................................@

.(.3 :roofstress level.....................................................................................................................................................................................................................@

. Refractive inde7 profile....................................................................................................................................................................................................................................

.' 9ongitudinal uniformit$....................................................................................................................................................................................................................................

6 /actor$ length specifications............................................................................................................................................................................................................................

6.1 ttenuation coefficient......................................................................................................................................................................................................................................

6.# +hromatic dispersion coefficient.......................................................................................................................................................................................................................

6.3 :olari2ation mode dispersion coefficient.....................................................................

.....................................................................................................................................6

( lementar$ cable sections.................................................................................................................................................................................................................................6

(.1 ttenuation.......................................................................................................................................................................................................................................................6

(.# +hromatic dispersion...................................................................................................

.....................................................................................................................................(

ppendi7 ! A %pectral attenuation modelling.................................................................................................................................................................................................................(

ppendi7 !! A 7ample of the matri7 model..................................................................................................................................................................................................................

R comm !"a#$o! G.652 %&'()*+ $

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R comm !"a#$o! G.652

CHARACTERISTICS OF A SINGLE-MODE OPTICAL FIBRE CABLE

(revised in 1997

Sco/

This Recommendation describes a single-mode fibre which has the 2ero-dispersion wavelength around1310 nm and which is optimi2ed for use in the 1310 nm wavelength region and which can also beused in the 1 0 nm wavelength region &where this fibre is not optimi2ed).

This fibre can be used for analogue and for digital transmission.

The geometrical optical transmission and mechanical characteristics of this fibre are described belowtogether with applicable test methods.

The meaning of the terms used in this Recommendation and the guidelines to be followed in themeasurements to verif$ the various characteristics are given in Recommendation G.6 0.

2 R 0 r !c 1

The following !T"-T Recommendations and other references contain provisions which throughreference in this te7t constitute provisions of this Recommendation. t the time of publication theeditions indicated were valid. ll Recommendations and other references are subBect to revisionC allusers of this Recommendation are therefore encouraged to investigate the possibilit$ of appl$ing themost recent edition of the Recommendations and other references listed below. list of the currentl$valid !T"-T Recommendations is regularl$ published.

A !T"-T Recommendation G.6 0 &1''() !efinition and test methods for the relevant parameters of sin"le-mode fi#res .

A !T"-T Recommendation G.6 3 &1''() $haracteristics of a dispersion-shifted sin"le-modeoptical fi#re ca#le .

A !T"-T Recommendation G.6 @ &1''() $haracteristics of a cut-off shifted sin"le-modeoptical fi#re ca#le .

A !T"-T Recommendation G.6 &1''6) $haracteristics of a non-%ero-dispersion shifted sin"le-mode optical fi#re ca#le .

A !T"-T Recommendation G.663 &1''6) &pplication related aspects of optical fi#re amplifier

devices and su#-s'stems . A !T"-T Recommendation G.6 1 &1''6) Functional characteristics of interoffice and

lon"-haul line s'stems usin" optical amplifiers, includin" optical multiple in" .

A !T"-T Recommendation G.' &1''6) !i"ital line s'stems #ased on the 1)** +#it s and the*/ +#it s hierarch' on optical fi#re ca#les .

A !T"-T Recommendation G.' ( &1'' ) 0ptical interfaces for e uipments and s'stemsrelatin" to the s'nchronous di"ital hierarch' .

A ! + :ublication ('3-# :art # &1''#) 0ptical fi#res 2 3art 4 3roduct specifications .

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T rm$!o3o,y

/or the purposes of this Recommendation the definitions given in Recommendation G.6 0 appl$.

' A44r $a#$o!1This Recommendation uses the following abbreviationsG:a Gigapascals%D< %$nchronous Digital

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measured according to the Reference Test 5ethod &RT5) and the core concentricit$ error the former willconstitute the reference.

5.' No!-c$rcu3ar$#y

5.'. Mo" 0$ 3" !o!-c$rcu3ar$#y

!n practice the mode field non-circularit$ of fibres having nominall$ circular mode fields is found to be sufficientl$ low that propagation and Bointing are not affected. !t is therefore not considerednecessar$ to recommend a particular value for the mode field non-circularit$. !t is not normall$necessar$ to measure the mode field non-circularit$ for acceptance purposes.

5.'.2 C3a""$!, !o!-c$rcu3ar$#y

The cladding non-circularit$ should be less than #F. /or some particular Bointing techni4ues and Bointloss re4uirements other tolerances ma$ be appropriate.

5.5 Cu#-o00 a 3 !,#

Three useful t$pes of cut-off wavelength can be distinguisheda) cable cut-off wavelength ccC

b) fibre cut-off wavelength cC

c) Bumper cable cut-off wavelength cB.

The correlation of the measured values of c and cc and cB depends on the specific fibre and cabledesign and the test conditions. *hile in general cc cB c a 4uantitative relationship cannot easil$

be established. The importance of ensuring single-mode transmission in the minimum cable length between Boints at the minimum s$stem operating wavelength is paramount. This ma$ be performed b$recommending the ma7imum cable cut-off wavelength cc of a cabled single-mode fibre to be either 1#60 or 1#(0 nm.

, T 1 A sufficient wavelength margin should be assured between the lowest-permissible s$stem operatingwavelength s and the highest-permissible cable cut-off wavelength cc.

, T # A To prevent modal noise effects and ensure single-mode transmission in cables of length less than # m&e.g. fibre pigtails short Bumper cables) the ma7imum c for fibres to be used should not be higher than1# 0 nm when measured under the conditions of the relevant RT5 of Recommendation G.6 0.

, T 3 A To prevent modal noise effects and ensure single-mode transmission in cables with lengths between# m and #0 m &e.g. fibre pigtails short Bumper cables) the ma7imum cB should not be higher than either 1#60or 1#(0 nm.

%ince specification of cable cut-off wavelength cc is a more direct wa$ of ensuring single-modecable operation specif$ing this is preferred to specif$ing fibre cut-off wavelength c.

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5.6 55& !m 3o11 / r0orma!c

!n order to ensure low-loss operation of deplo$ed 1310 nm optimi2ed fibres in the 1 0 nmwavelength region the loss increase of 100 turns of fibre loosel$-wound with a 3(. mm radius andmeasured at 1 0 nm shall be less than 1.0 d?.

/or %D< and *D5 applications the fibre ma$ be used at wavelengths e7ceeding 1 0 nm. The1.0 d? ma7imum loss shall appl$ at the ma7imum wavelength of anticipated use &which would be 1 0 nm). The loss at the ma7imum wavelength ma$ be proBected from a loss measurement at1 0 nm using either spectral loss modelling or a statistical database for that particular fibre design.

lternativel$ a 4ualification test at the longer wavelength ma$ be performed.

, T 1 A 4ualification test ma$ be sufficient to ensure that this re4uirement is being met.

, T # A The above value of 100 turns corresponds to the appro7imate number of turns deplo$ed in all splicecases of a t$pical repeater span. The radius of 3(. mm is e4uivalent to the minimum bend-radius widel$accepted for long-term deplo$ment of fibres in practical s$stem installations to avoid static-fatigue failure.

, T 3 A !f for practical reasons fewer than 100 turns are chosen to implement this 3(. mm test it is

suggested that not less than @0 turns and a proportionatel$ smaller loss increase be used. , T @ A !f bending radii smaller than 3(. mm are planned to be used in splice cases or elsewhere in thes$stem &for e7ample R H 30 mm) it is suggested that the same loss value of 1.0 d? shall appl$ to 100 turns of fibre deplo$ed with this smaller radius.

, T A The 1 0 nm bend-loss recommendation relates to the deplo$ment of fibres in practical single-modefibre installations. The influence of the stranding-related bending radii of cabled single-mode fibres on the loss

performance is included in the loss specification of the cabled fibre.

, T 6 A !n the event that routine tests are re4uired a small diameter loop with one or several turns can beused instead of the 100-turn test for accurac$ and measurement ease of the 1 0 nm bend sensitivit$. !n thiscase the loop diameter number of turns and the ma7imum permissible bend loss for the several-turn testshould be chosen so as to correlate with the 1.0 d? loss recommendation of the 3(. mm radius 100-turn

functional test.

5.* Ma# r$a3 /ro/ r#$ 1 o0 # 0$4r

5.*. F$4r ma# r$a31

The substances of which the fibres are made should be indicated.

, T A +are ma$ be needed in fusion splicing fibres of different substances. :rovisional results indicate thatade4uate splice loss and strength can be achieved when splicing different high-silica fibres.

5.*.2 Pro# c#$ ma# r$a31

The ph$sical and chemical properties of the material used for the fibre primar$ coating and the bestwa$ of removing it &if necessar$) should be indicated. !n the case of single Bac=eted fibre similar indications shall be given.

5.*. Proo01#r 11 3 3

The specified proofstress p shall be at least 0.3 G:a which corresponds to a proofstrain of appro7imatel$ 0. F. :roofstress is often specified as 0.6' G:a.

, T A The definitions of the mechanical parameters are contained in 1.#>G.6 0 and #.6>G.6 0.

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5.7 R 0rac#$ $!" 8 /ro0$3

The refractive inde7 profile of the fibre does not generall$ need to be =nownC if one wishes tomeasure it the reference test method in Recommendation G.6 1 ma$ be used.

5.) Lo!,$#u"$!a3 u!$0orm$#y

"nder stud$.

6 Fac#ory 3 !,# 1/ c$0$ca#$o!1

%ince the geometrical and optical characteristics of fibres given in clause are barel$ affected b$ thecabling process this clause will give recommendations mainl$ relevant to transmission characteristicsof cabled factor$ lengths.

nvironment and test conditions are paramount and are described in the guidelines for test methods.

6. A## !ua#$o! co 00$c$ !#ptical fibre cables covered b$ this Recommendation generall$ have attenuation coefficients below

0. d?>=m in the 1310 nm wavelength region and below 0.@ d?>=m in the 1 00 nm wavelengthregion.

, T 1 A The lowest values depend on the fabrication process fibre composition and design and cable design.Ialues in the range 0.3-0.@ d?>=m in the 1310 nm region and 0.1(-0.# d?>=m in the 1 0 region have beenachieved.

, T # A The attenuation coefficient ma$ be calculated across a spectrum of wavelengths based onmeasurements at a few &3 to ) predictor wavelengths. This procedure is described in ppendi7 ! and ane7ample is given in ppendi7 !!.

6.2 C roma#$c "$1/ r1$o! co 00$c$ !#

The ma7imum chromatic dispersion coefficient shall be specified b$

A the allowed range of the 2ero-dispersion wavelength between 0min = 1300 nm and0ma7 = 13#@ nmC

A the ma7imum value % 0ma7 = A0.0'3 ps>&nm# J =m) of the 2ero-dispersion slope.

The chromatic dispersion coefficient limits for an$ wavelength within the range 1#60-1360 nm shall be calculated as

( ) !5

10

@

3@

0

= ma7 min

( ) !5

#0

@

3@

0

= ma7 ma7

, T 1 A s an e7ample the values of 0min 0ma7 and %0ma7 $ield chromatic dispersion coefficient magnitudes| ! 1 | and | ! # | e4ual to or smaller than the ma7imum chromatic dispersion coefficients in the table

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9a 3 !,#%!m+

Ma8$mum c roma#$c"$1/ r1$o! co 00$c$ !#

:/1(%!m.;m+