# Fileset

[ofc_fuse+sem4.pdf](https://mdr.nims.go.jp/filesets/48fa5b4a-857d-498c-b500-dbc3219c0b9a/download)

## Creator

[TODOROKI, Shin-ichi](https://orcid.org/0000-0003-3986-1900)

## Rights

Creative Commons BY Attribution 4.0 International[Creative Commons BY Attribution 4.0 International](https://creativecommons.org/licenses/by/4.0/)

## Other metadata

[Partially self-pumped fiber fuse propagation through a white tight-buffered single-mode optical fiber](https://mdr.nims.go.jp/datasets/6938efc1-1a65-4b93-892d-e4b2a72276de)

## Fulltext

ofc_fuse.dviOFC/NFOEC OTh4I.4 (1)'&$%Partially Self-pumpedFiber Fuse Propagationthrough a White Tight-bufferedSingle-mode Optical FiberShin-ichi TODOROKI NIMS, Japan~WOptical fiberPOWER0Fiber laser123Slide 1Date: 8 Mar. (Thu) 2012, 16:30–17:00 (PSC)Venue: Los Angeles Convention Center (Room 503)AbstractThe propagation threshold power through a white tight-buffered fiber was foundto be 3% less than that through an acrylate-coated fiber because the pigments inthe buffer backscatter the visible emission that pumps a fuse.OFC/NFOEC OTh4I.4 (2)'&$%How much the minimum power isfor fiber fuse propagation?~WOptical fiberPOWER0Fiber laser123Slide 2'&$%It depends on the fiber you use.SMF HAF PCF<<×10Slide 3OFC/NFOEC OTh4I.4 (3)'&$%How much the minimum power isfor fiber fuse propagation?SMFSlide 4'&$%SMFWavelength (µm)Threshold power (W)1.01.11.21.31.41.0 1.1 1.2 1.3 1.4 1.5 1.6ReporterSeo (’03)Takenaga (’08)Abedin (’10)Rocha (’11)Todoroki (’11)_tight−bufferedPth also depends on the reporters .Why?Slide 5OFC/NFOEC OTh4I.4 (4)'&$%Initiation Difficult to ignite a fuse at ∼Pth~WOptical fiberPOWER0Fiber laser123Slide 6'&$%Their definition Power when a fuse disappearedSMFWavelength (µm)Threshold power (W)1.01.11.21.31.41.0 1.1 1.2 1.3 1.4 1.5 1.6ReporterSeo (’03)Takenaga (’08)Abedin (’10)Rocha (’11)Todoroki (’11)_tight−buffered~WPOWER0Fiber laserSlide 7OFC/NFOEC OTh4I.4 (5)'&$%My definition Minimum power for propagationSMFWavelength (µm)Threshold power (W)1.01.11.21.31.41.0 1.1 1.2 1.3 1.4 1.5 1.6ReporterSeo (’03)Takenaga (’08)Abedin (’10)Rocha (’11)Todoroki (’11)_tight−buffered~WFiber laserOFFPOWER0Slide 8'&$%Today’s talk −3% with white tight-bufferSMF−28eWavelength (µm)Threshold power (W)1.01.11.21.31.41.0 1.1 1.2 1.3 1.4 1.5 1.6CoatingAcrylate−coated+ Tight buffer250 µm900 µmWhy Pth depends on fiber coatings?Slide 9OFC/NFOEC OTh4I.4 (6)'&$%OVERVIEWPartially self-pumped fiber fuse propagationEnergy balanceHow the tight buffer gives some energy to a fuse?EvidenceHow this mechanism at ∼Pth is proved?Self-pumpingWhat occurs if a fuse is pumped at >>Pth?Slide 10'&$%Energy balance~WLaser light Optical fiber Hollow damageDissipative soliton :Akhmediev (’08)TemperatureReaction zoneINOUT∂T∂t=︷︸︸︷χαI +︷ ︸︸ ︷D∂2T∂x2− k(T − T0)How this energy flow is modified by a tight buffer?Slide 11OFC/NFOEC OTh4I.4 (7)'&$%Energy balance IO modification by tight buffer• Input– Laser–• Output– Heat– LightTemperatureReaction zoneINOUTSelf-pumpingրSlide 12'&$%Energy balance Heat flow vs. fusing speed~W~mm~msecLaser lightPropagationHeat conductionSlide 13OFC/NFOEC OTh4I.4 (8)'&$%Energy balance Light flow via tight buffer• White pigmentsbackscatter the emission• that is absorbed by plasma& SiO in the glass meltSlide 14'&$%Energy balance Light flow along the fiberTight bufferSlide 15OFC/NFOEC OTh4I.4 (9)'&$%OVERVIEWPartially self-pumped fiber fuse propagationEnergy balanceBack-scattered visible emission possibly pumps a fuse.EvidenceHow this mechanism at ∼Pth is proved?Self-pumpingWhat occurs if a fuse is pumped at >>Pth?Slide 16'&$%Evidence Void interval vs. Power (∼Pth)SMF1480 nm3.5 WPeriodicity©2 W ×1.5 W ×1.3 W ©↓ ×PthSlide 17OFC/NFOEC OTh4I.4 (10)'&$%Evidence Void train left in damaged fibers1310nm1.16W vs 1.15W<Pth >PthSlide 18'&$%Evidence Ultra-high speed videography1024-step4µs / frame1µs-exposure    w/ ND filters128x16PhotronWavelength:380–790nmFiberlaser1480nmND filterSMF-28Zoom lensSlide 19OFC/NFOEC OTh4I.4 (11)'&$%Evidence In situ observation & void trainSlide 20'&$%Evidence 2-mode switching• Dark & fast w/ periodic voids• Flash & slow w/o voidsN5mm: Density ofbullet-like voidsSlide 21OFC/NFOEC OTh4I.4 (12)'&$%Evidence N5mm increased before terminationPosition (mm)N5mm020406080100PropagationSelf−terminatedreduced to 1.16 W, 1310 nm0 100 200 300 400 500<PthSlide 22'&$%Evidence N5mm through a coated segmentPosition (mm)N5mm020406080100PropagationWhite oil paint1.19 W, 1310 nm200 100 0 −100>PthPosition (mm)020406080100PropagationBlack oil paint1.19 W, 1310 nm200 100 0 −100>PthFiberLaserStabilized through white oil paintSlide 23OFC/NFOEC OTh4I.4 (13)'&$%Evidence White protective layers everywhereRibbon cables, Ceramic (ZrO2) ferrules, etc.Slide 24'&$%OVERVIEWPartially self-pumped fiber fuse propagationEnergy balanceBack-scattered visible emission possibly pumps a fuse.EvidenceA self-pumped fuse leaves a stabilized void pattern.Self-pumpingWhat occurs if a fuse is pumped at >>Pth?Slide 25OFC/NFOEC OTh4I.4 (14)'&$%Self-pumping Void interval vs. Power (>>Pth)9 W7 W5 W3.5 WNo apparent differenceSlide 26'&$%Self-pumping Plasma shape vs. Power (>>Pth)+Self-pumpingSlide 27OFC/NFOEC OTh4I.4 (15)'&$%Self-pumping Different temperature profilesOFF<7µsec? ?+Self-pumpingSlide 28'&$%Self-pumping Frozen “void formation cycle”• 1.17 m/s⇓one voidper 18.7 µs1480nm 9WΛl 1+2 l 2• Need statistical analysisVoid length normalization: l′1+2 =l1+2Λ, l′2 =l2ΛSlide 29OFC/NFOEC OTh4I.4 (16)'&$%Self-pumping l′2-distributionl’2Count (total: 48)051015 v|0.5 1.0 1.5 2.0 2.5 3.0 3.5l’2Count (total: 44)051015v|0.5 1.0 1.5 2.0 2.5 3.0 3.5l’  > 12l’  < 12Quenching+Self-pumping• Longer quenching time promotes void separationSlide 30'&$%Self-pumping l′1+2-distributionAcrylate−coatedl’2l’ 1+27.07.58.08.59.09.5average0.5 1.0 1.5 2.0 2.5 3.0 3.5l’2Count (total: 48)051015 v|0.5 1.0 1.5 2.0 2.5 3.0 3.5+Tight bufferl’2l’ 1+27.07.58.08.59.09.50.5 1.0 1.5 2.0 2.5 3.0 3.5l’2Count (total: 44)051015v|0.5 1.0 1.5 2.0 2.5 3.0 3.5Slide 31OFC/NFOEC OTh4I.4 (17)'&$%Self-pumping makes quenching time longer ...• and promotes void separation‖bridge formationl’  > 12Quenching+Self-pumping• A bridge appears only after the quench starts.Slide 32'&$%Self-pumping No bridge in “in situ image”• Quenching promotes bridge formation.Slide 33OFC/NFOEC OTh4I.4 (18)'&$%Self-pumping Quenching during propagationPropagation+Self-pumpingQuenching• Bridge formation⇐= Melt incl. a cavity being quenchedSlide 34'&$%SUMMARYPartially self-pumped fiber fuse propagationEnergy balanceBack-scattered visible emission possibly pumps a fuse.EvidenceA self-pumped fuse leaves a stabilized void pattern.Self-pumpingLonger quenching time promotes void separation.Fiber coatings promote self-pumping: Pth ցSlide 35