Angle Cleaving Larson Donald

8/12/2019 Angle Cleaving Larson Donald

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Mechanical Splice with Keyed

Angle Cleaved Fibers

9i28 KeyedAngleSplice R4.ppt

Don Larson

Lab Project Manager

3M CompanyCommunication Markets Division

Austin, Texas

Co-authors:

-Dr. William V. Dower-Dan J. Treadwell


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Fiber optic mechanical splices with keyed, angle

cleaved fibers are an attractive option for achievinglow return loss for analog video applications,

especially in outside plant where long term splice

stability is an important consideration.


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Mechanical splices: in outside plant over 20 years

Fast and easy installation without investing in fusion equipment

Perpendicular cleave fibers: well accepted for FTTH, especially in Asiafor data and digital video

Standard video transmission in North America is analog

Analog networks require stringent reflection performance

Splice joint


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For AM-VSB (analog video) Telcordia GR-765

requires 45dB with objective of 50dB

IEC 61753-131-3 Grade 1 specification is 60dB

Telcordia GR-765 Generic Requirements for Single Fiber Single-Mode Optical Splices

and Splicing Systems

IEC 61753-131-1 Fibre Optic Interconnecting Devices and Passive Components-Performance Standard Part 131-3: Singlemode Mechanical Fibre Splice for Category U

Uncontrolled Environment


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Return loss (RL) of 60dB: difficult for

perpendicular cleaved mechanical splices to meet at

extremes of outside plant temperatures of-40C/75C (-40F/167F)

We will show that keyed angle cleave mechanical

splices are a viable technique for outside plantanalog signal transmission systems

Keyed, Angle Cleave Splice


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Reflection:light which is reflected from an interface

Some reflection from an interface becomes return loss

Return loss (RL): reflected light which is guided in the

fiber core toward transmitter (backreflection)

Keyed, Angle Cleave SpliceReflection

Return loss Transmitted LightIncident Light


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Gel: thixotropic dispersion

in silicone fluid

Matches index of opticalfibers at room temperature

Refractive indices of gel

and glass change withtemperature

Index change withtemperature (dn/dT)

Glass

Particles


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Calculated


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Gel


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No Significant Optical Performance Change

Temp Cycle Chamber

Water Tank


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Measured: HP Reflectometer


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*Due to constructive interference


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Pairof Fiber Ends in Gelat -40Cor 75C

Theoretical MaximumReturn Loss vs. Fiber Endface Angle

o o o


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180misaligned

Centers are 15.3 um apart

For both cases:

Clad Diameters = 125 um

Edge R = 0 um (not polished)

Cleave Angle = 7

45misaligned

Centers are 5.9 um apart


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0 samples remained above 70dB, fully met analog requirements

42 mis-keyed fiber ends, the RL was generally better than 60db180mis-keyed fiber ends, the RL was not acceptable for analog

1310nm

T/C -40C/75C, 21 cycles


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Open

AluminumSplice Element

ClosedAluminum

Splice Element


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Cleaving mechanism

automatically tensions, torques,scribes and cleaves fiber


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Angle Cleave Fiber using Fiber HolderInsert Fibers and

Activate Splice


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When second holder is rotated 180 degrees, the two fibers will be keyed

7 Degree Angle Cleave


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Optical Stability of Mechanical Splice -40C to 75C


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Fiber optic mechanical splices with keyed,angle cleave fibers are an attractive option

for achieving low return loss for analog video

applications, especially in outside plantwhere long term splice stability is an

important consideration.


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THANK YOU

Contact Information: [email protected]

Authors:-Donald K. Larson

-Dr William V. Dower

-Dan J. Treadwell

Documents

Angle Cleaving Larson Donald