# Fileset

[lmt_fuse4MDR.pdf](https://mdr.nims.go.jp/filesets/e7b9fd0c-7267-4402-b360-4a15376e3d6f/download)

## Creator

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

## Rights

In Copyright[In Copyright](http://rightsstatements.org/vocab/InC/1.0/)

## Other metadata

[Fiber fuse behavior veiled in its strong light emission](https://mdr.nims.go.jp/datasets/82b7bafd-e39c-4de2-a265-1faa2e8538fa)

## Fulltext

LumiMat 2015 (1)✬✫✩✪Fiber fuse behaviorveiled in its strong light emissionShin-ichi TODOROKI NIMS, Japan~1 m/sSlide 1✬✫✩✪Introduction Dissipative solitonGrass fire:Energy feedDissipationLaser (>1W) −→thru a single-mode fiberSiO2∆−→ SiO2−x+x2O2Slide 2LumiMat 2015 (2)✬✫✩✪Introduction What I’ve done.∗∗0501001501990 1995 2000 2005 2010 2015YearTalks & Publications on Fiber Fusesource: fiberfuse.infoSlide 3✬✫✩✪OVERVIEWFiber fuse behaviorMotivationWhy should we investigate it?TerminationHow it is trapped at termination devices?InitiationWhat is known about its initiation process?Slide 4LumiMat 2015 (5)✬✫✩✪Termination Proposed technologiesfor single-mode fibers in opt. commun.• Remote sensing → Power shutdown• Local trap → Excess dissipationSlide 9✬✫✩✪Termination (1) Pressure leakageLaserlightHole-assisted � ber(Takenaga 2008)Photonic crystal � ber(Hanzawa 2010)Etched � ber(Dianov 2004)Slide 10LumiMat 2015 (6)✬✫✩✪Termination (2) Mode field expansionLaserlightzrφLarger MFD(Wyatt 2001)TEC fiber(Hand 1989)Why it is trapped in spite ofddz∫I(r, φ)dS = const. ?=⇒ Need to know its propagation behaviorSlide 11✬✫✩✪Propagation The key is left behind it.⇓ Power shutdownPeriodic voidsSlide 12LumiMat 2015 (7)✬✫✩✪Propagation Void interval vs. Pump power12.515.017.520.022.52.5 5.0 7.5Pump power (W)Λ (µm)SMF−28e, 1480 nmSlide 13✬✫✩✪Propagation Self-pumping effectΛ2 < Λ1Slide 14LumiMat 2015 (8)✬✫✩✪Propagation Response delay due to viscosity1480 nm, 7 W∆ Λ = − 0.8 µ m∆ t =  0.4 ms2021−2.50.02.55.0Position (mm)Void interval (µm)∆ Λ = + 0.6 µ m∆ t =  0.2 ms2021−2−10123Position (mm)Slide 15✬✫✩✪Termination The mechanismLas erlightDelayed expansion⇓Termination ⇐ Power feed exhaustionddt∫I(r, z0)A(r, z0)dS < 0Slide 16LumiMat 2015 (9)✬✫✩✪OVERVIEWFiber fuse behaviorMotivationBetter risk management of high power-over-fiber apps.TerminationViscous silica melt causes a delay in response.InitiationWhat is known about its initiation process?Slide 17✬✫✩✪Initiation Quantitative evaluation is very hardSiO2∆−→ SiO2−x+x2O2~ WHeat~ 1m / �How much is the minimum laser power for initiation?Slide 18LumiMat 2015 (10)✬✫✩✪Initiation An alternative criteriaThe minimum laser power for propagationSMF−28e1480 nmP th0.20.30.40.50.61.0 1.5 2.0 2.5 3.0 3.5Pump power (W)Propagation speed (m/s)No info about initiation!Slide 19✬✫✩✪Initiation To quantify heat & time,• Arc discharge in a fusion splicerLaser: 1.5 – 7 W100%,130%,160% for 1 sec.Slide 20LumiMat 2015 (11)✬✫✩✪Initiation Heating scheme=⇒SiO2∆−→ SiO2−x+x2O2−→10 trials=⇒ No change / Deformation / Initiation / Melt downSlide 21✬✫✩✪Initiation Arc discharge: 100％0510Arc dischargeintensity: 100 %2 3 4 5 6 7Laser power (W)Number of countsStatusFailedInitiatedSlide 22LumiMat 2015 (12)✬✫✩✪Initiation Dacay time0.00.51.0Arc dischargeintensity: 100 %2 3 4 5 6 7Laser power (W)∆t / sec∆ tLaserFusionsplicerPowermeter0.000.050.100.150.200.0 0.5 1.0Time (s)Insertion loss (dB)Failed+laser powerInitiatedSlide 23✬✫✩✪Initiation Increasing arc discharge051005100510Arc dischargeintensity: 160 %130 %100 %2 3 4 5 6 7Laser power (W)Number of countsStatusFailedSpot deformedSelf−terminatedInitiatedNo periodicvoidsSlide 24