Lifetime Predictions of Bend Optimized GGP Single Mode Fiber for ...

Lifetime Predictions of Bend Optimized GGP Single Mode Fiber for FTTHRequirementsHen-Tai Shang, Li-Shing Hou, Gary Chou, Ray HsiehPrime Optical Fiber CorporationScience Park, Chu-Nan 350 Taiwan Roc+886-37-586999 hentai@pofc.com.twAbstractFiber To The Home (FTTH) demand bend optimized fiber, however,most commercially available bend enhanced fiber only addressesthe optical performance at tight bends, it does not improve themechanical property of the fiber. This paper describes designs of theGGP single mode fiber which improves the fiber mechanicalproperty independently to its optical performance. Combining theGGP fiber design with low bending loss performs, bend optimizedsingle mode fibers were developed. Their dynamic fatigueparameter nd were found to be greater than 30. With thatinformation, we can estimate their lifetime.Keywords: GGP; fiber; FTTH; mechanical failure; lifetime;fatigue parameter; bend; MDU.1. IntroductionGGP fiber first developed by 3M Company and presented in thisconference in 1995 [1] The term GGP has been designated as ageneric descriptor of this fiber design with specific reference to theGlass core/Glass clad/Permanent polymetric coating and withadditional two layer of Acrylate coating construction (see Figure 1).network structure simulation model the allowed fiber storage lengthand bending radius R of storage depend critically on the fatigueparameter n. In this paper we will show by applying a 5 um thick P-coating to a normal ITU-T G.657 fiber, a new class of GGP singlemode fiber which has both good optical performance and superiormechanical property was created. Its aging properties, fatigueparameter n, and lifetime predictions were studied.2. GGP Single Mode Fiber DesignGGP(115/125/250) designate fiber with glass clad = 115 um, P-coatOD = 125 um and Acrylate coating to 250 um. “GGPR15” fiber isa low bending loss fiber (G657A) with the above construction.GGP(125/135/250) designate fiber with glass clad = 125 um, P-coatOD = 135 um and Acrylate coating to 250 um. “GGPR15X” fiber isa low bending loss fiber (G657A) with the above construction.3. Fiber Static Fatigue Aging TestThe static fatigue aging test schematic is show in Figure 2. To testany fiber, batches of twenty short fiber pieces were loaded intotest Face Plate. The Face Plate distance is adjusted so the glassfiber bending gap (d1) is equal to 3.5 mm. Loaded Face Plate wasimmerged in 90 degree Celsius hot water, and an acoustic sensoris used to monitor the fiber breakage and automatically recordedbreakage times. Failure probability verses breakage times wererecorded and results were shown in Figure 3.Four Classes of fiber were tested: Commercial legacy fiber frommany different sources designated as STD(125/250), the originalGGP multimode fiber designated as GGP(100/125/250) alongwith the two new classes of fiber GGP(115/125/250) andGGP(125/135/250).Figure 1. Cross section of GGP fiber constructionThe original design was directed towards multimode optical fiberfor use in data communication application. Later GGP multimodefiber with 12.5 um thickness P-coating was used in ferrule-lessinterconnect applications [2], GGP fiber comprises this patented P-coating resists strength degradation upon exposure to hightemperature and high humidity environments. It provide muchimproved mechanical protection to the fiber glass cladding, so GGPfiber do have much longer lifetime expectation than legacy fiber.Recently ITU-T Rec. G.657 specified a class of bending lossinsensitive single mode fiber, and its more stringent lifetimerequirements is discussed in its Appendix 1; for a simplifiedFigure 2 Static Fatigue Aging Test setupInternational Wire & Cable Symposium 266 Proceedings of the 57th IWCS

GGP(115/125/250)GGP(125/135/250)GGP(100/125/250)Dynamic fatigue data2008/7/24Date : Platen Velocity = 1000um/s,100um/s,10um/s,1um/s X-Bar = -0.259POFC GGPR15 G008Z7B15F1DYFiber ID : Sample Size for each platen velocity = 16 Y-Bar = 0.787Cladding : Temperature = 23 +/- 1 C Nd = 34.51OD 114.7 umCoating OD : 246.8 um Humidity = 46 +/- 2 % Ndu = 36.34Operator : 370Pre-Conditioning time Ndl = 32.87= 18 HrsFailure Probability (%)Log (fracture stress) GPa0.90.850.80.750.7GGPR15y = 0.0298x + 0.7943R 2 = 0.9588Nd = 1/0.0298+1 = 34.50.65STD(125/250)Time to break (sec)•Static Fatigue Bending Gap d1= 3.5mm ; Immerse @90℃ DI Water.Figure 3. Static fatigue aging test resultsThe results show Legacy fibers all have median Failure Time lessthan 5 minutes, where GGP fibers all have much longer (100 to10,000 times longer) median Failure Time.4 Fiber Dynamic Fatigue MeasurementWe followed IEC-60793-1-33 Annex B set up the dynamicfatigue two-point bending method as shown in Figure 4. Thewhole movable sample holder is inside a temperature andhumidity controlled box. The test set is shown in Figure 5. Alltests were conducted in the same controlled temperature andhumidity range. Test samples were also pre-conditioned for atleast 12 hours as required. A test report sample was shown inFigure 6, and typical measured results (nd) were summarized inTable 1.0.6-2 -1.5 -1 -0.5 0 0.5 1 1.5log (V/r)Figure 6. Test report on one sample of GGPR15 fiberTable 1. Summary of Dynamic Fatigue Parameter ndCommercial fibers of company C and company F show theirfiber’s nd around 19 and our GGP fibers all show nd around 34.5 Lifetime predictionBased on experimental lifetime data on fiber wrap over 3 mmdiameter rod and the relative lifetime data of different fiber class,we have extrapolated their expected lifetime based on Power LawTheory [IEC TR 62048] as shown in figure 7.Figure 4. Schematic of two point bending methodFigure 5. Dynamic Fatigue Two Point Bending Test setupFigure 7. Extrapolated life time based on power lawtheory and lifetime dataOur lifetime prediction uses n = 18 for legacy fiber, and n=30 for alltype of GGP fibers. The lifetime calculated is for a simplifiednetwork structure simulation model with each individual one meterfiber wrap over of different diameter frame inside cassette and thefailure rate = 0.001% [3]. The results show the minimum frameInternational Wire & Cable Symposium 267 Proceedings of the 57th IWCS

diameter could be as small as 8 mm for all GGP fiber networks tosurvive 20 years, where legacy fiber networks could reach greaterthan 5 % failure rate in less than an hour.6 Bending LossGGPR15 and GGPR7 fiber, in compliance with ITU-T G.657A andITU-T G.657B respectively, were developed and their bending lossis shown in Figure 8.10 Authors BiographyHen-Tai Shang, received his BS degree fromNCU in Taiwan in 1972. After militaryservice, he went to the US for his graduatestudies. He received his PhD degree from U.of Illinois at Urbana-Champaign and joinedAT&T Bell Laboratories in 1979. After 11years of R/D work at Bell Labs, he went backto Taiwan in 1990 and a year later foundedPrime Optical Fiber Corporation; now he isthe company Chief Technology Officer. He has engaged indevelopment work of many different optical fibers forcommunications, fiber sensors, and fiber lasers. Currently he isalso serving as VP of Taiwan Optical Communication IndustryAlliance (TOCIA).Li-Shing Hou received his PhD degree inPhysics from National Tsing-Hua Universityin 1999 and then he joined Academica Sinicawhere he worked for CERN LHC project todevelop mini optical devices. In 2007 hejoined Prime Optical Fiber Corporationwhere his main task is on fiber applicationand product management.Figure 8. Bending Loss at 1550 nm7 ConclusionsWe have developed a new class of GGP single mode fiber. Thesefibers feature low bending loss and long lifetime - A class of trulybend optimized fiber. This new class GGP fiber can be fusionsplicedto legacy fiber by using ordinary fusion splice machines. Itis also suitable to use with commercial available mechanical splicesand field assembly connectors. Using these fibers, a very simple 3mm OD cable can be made with one or two 250 um GGP fibersinside. Such cable will be ideal for FTTH and MDU deployment.8 AcknowledgmentsSpecial thanks to 3M Company for their assistance to thedevelopment of this work.9 References[1] J. C. Novack, F. Bacon, B. J. Cronk, J. W. Laumer, J. M.Moser and B. A. Rabine, “Optical Fiber Design For ImprovedMechanical Properties,” p. 162 International Wire & CableSymposium Proceedings 1995.[2] T. P. Berger, J. W. Laumer, C. B. Walker Jr. and J. C. Novack,“Fiber Performance in Ferrule-Less Interconnects,” p. 560International Wire & Cable Symposium Proceedings 1999.[3] ITU-T Rec. G.657 (12/2006) Appendix 1.Gary Chou, received his master degree fromNCU in Taiwan in 1995. After militaryservice, he joined Prime Optical FiberCorporation in 1997 where he worked onmany different optical fibers forcommunications, fiber sensors, and fiberlasers, currently as R&D manager.Ray Hsieh received his master degree inPhysical Chemistry from National Tsing-HuaUniversity in 2000. In 2001 he joined thePrime Optical Fiber Corporation, where heworked in the R&D group, and now is atechnical support engineer.International Wire & Cable Symposium 268 Proceedings of the 57th IWCS