Fiber Optic Cable Preparation toEnsure Stable OperationEnsure Stable Operation

Richard F. Chuska, William J. Thomes Jr.,Melanie N. Ott, Frank V. LaRocca,

Robert C. Switzer, Shawn L. Macmurphy

SPIE Optics + Photonics 2008

Overview

• How to properly precondition a fiber optic cable

• Performance of different types of fiber optic cablesthat are properly prepared

• What happens when you do not properlyprecondition the fiber optic cable

Fiber Optic Cables

• TEQS Powerflex hard-polymer coated– 365/400/425 (TEQS)/730 (TEFZEL buffer)

– Manufactured by InnovaQuartz

• Flexlite– 400/440 Step Index Fiber– 400/440 Step Index Fiber

– E-PTFE buffer, Kevlar aramid braid, fluoropolymer jacket

– Manufacture by W. L. Gore

• International Space Station Fiber– 100/140 Graded Index Carbon Coated

– Fiberglass with Teflon coating, polymer jacket

– Manufactured by Brand-Rex Company

Fiber Optic Cables

• SMF with 1.8 mm PEEK– 9/125/250 SM fiber

– Expanded PTFE, PEEK tube, aramid strength members, outer polymerjacket

– Manufactured by W. L. Gore

• MTP cable• MTP cable– Mylar lamination, E-PTFE wrap,

Kevlar strength member, outer polymer jacket

– Manufactured by W. L. Gore

• Strong Tether Fiber Optic Cable (STFOC)– 9/125 SM fiber with acrylate coating

– Proprietary secondary buffer

– Manufactured by Linden Photonics

Cable Terminations

• FC connectors

– 2.5 mm ferrule• Ceramic outside

• Metal insert

– Keyed to adapter

• Cable connected to back of connector

– Metal crimp sleeve

– Cable strength members

(Kevlar) crimped

Thermal Preconditioning

• Cable lengths: 1, 3, and 6 meters

• Thermal Profile– -30°C to 130°C 60.00

80.00

100.00

120.00

140.00

Tem

per

atu

re(°

C)

Temperature Profile for Preconditioning

– -30°C to 130°C

– 2°C/min

– 1 hour dwell at extremes

• Cables were removed from thermal chamber andmeasured periodically during preconditioning study

-40.00

-20.00

0.00

20.00

40.00

60.00

0.00 500.00 1000.00 1500.00 2000.00 2500.00 3000.00Te

mp

erat

ure

(

Elapsed Time (min)

Thermal Preconditioning

1.50%

2.00%

2.50%

3.00%

Ch

ange

inC

able

Len

gth

com

par

ed

toIn

itia

lLe

ngt

h(%

)

Flexlite 1413 (6 m)

Flexlite 1413 (3 m)

Flexlite 1413 (1 m)

SMF28 PEEK (6 m)

SMF28 PEEK (3 m)

SMF28 PEEK (1 m)

ISS Cable (6 m)

ISS Cable (3 m)

0.00%

0.50%

1.00%

0 10 20 30 40 50 60 70 80 90 100

Ch

ange

inC

able

Len

gth

com

par

ed

toIn

itia

lLe

ngt

h(%

)

Number of Thermal Cycles

ISS Cable (1 m)

W.L. Gore 1997 MT (6 m)

W.L. Gore 1997 MT (3 m)

W.L. Gore 1997 MT (1 m)

TEQS 365/400 (6 m)

TEQS 365/400 (3 m)

TEQS 365/400 (1 m)

STFOC SMF28 (6 m)

Thermal precondition until cable length stabilizes

Shorter cables show a greater percentage change in cable length

Thermal Preconditioning

6

8

10

12O

vera

llC

han

gein

Len

gth

(cm

)

Flexlite 1413 (6 m)

Flexlite 1413 (3 m)

Flexlite 1413 (1 m)

SMF28 PEEK (6 m)

SMF28 PEEK (3 m)

SMF28 PEEK (1 m)

ISS Cable (6 m)

ISS Cable (3 m)

ISS Cable (1 m)

Cable termination stability is determined by length change at connector

Longer cable show an overall greater change in length

0

2

4

0 10 20 30 40 50 60 70 80 90 100

Ove

rall

Ch

ange

inLe

ngt

h(c

m)

Thermal Cycles

ISS Cable (1 m)

W.L. Gore 1997 MT (6 m)

W.L. Gore 1997 MT (3 m)

W.L. Gore 1997 MT (1 m)

TEQS 365/400 (6 m)

TEQS 365/400 (3 m)

TEQS 365/400 (1 m)

STFOC SMF28 (6 m)

Thermal Preconditioning

• Fibers must be cut to length before they arepreconditioned

• Cables must be subjected to thermal cycling untilshrinkage has stabilizedshrinkage has stabilized

Flexlite cable MTP cable ISS cable

Cable Shrinkage during Preconditioning

Fiber Cable Performance

OpticalSources

FiberSplitter

850 nm1310 nm1550 nm

Thermal Chamber

Source1550 nm

Multi-channelDetector

SourceMonitor

ThermalMonitor

Fiber Cable Performance

30

40

50

60

70

80

90

100

110

120

130

0.00

0.05

0.10

0.15

0.20

0.25

Tem

per

atu

re(°

C)

Len

gth

No

rmal

ize

dIn

sert

ion

Loss

(dB

/m)

Flexlite (1m) 850 nm

Flexlite (3m) 850 nm

Flexlite (6m) 850 nm

TEQS (1m) 850 nm

-50

-40

-30

-20

-10

0

10

20

30

-0.25

-0.20

-0.15

-0.10

-0.05

0 1000 2000 3000 4000 5000 6000 7000 8000 9000 10000

Tem

per

atu

re(

Len

gth

No

rmal

ized

Inse

rtio

nLo

ss(d

B/m

)

Elapsed Time (min)

TEQS (1m) 850 nm

TEQS (3m) 850 nm

TEQS (6m) 850 nm

Temperature

-50°C to 125°C, 2°C/min, 60 min dwell at extremes

Fiber Cable Performance

30

40

50

60

70

80

90

100

110

120

130

0.00

0.05

0.10

0.15

0.20

0.25

Tem

per

atu

re(°

C)

Len

gth

No

rmal

ize

dIn

sert

ion

Loss

(dB

/m)

SMF28 PEEK (1m) 1550 nm

SMF28 PEEK (6m) 1550 nm

SMF28 PEEK (3m) 1550 nm

STFOC SMF28 (6m) 1550 nm

-50°C to 125°C, 2°C/min, 60 min dwell at extremes

-50

-40

-30

-20

-10

0

10

20

30

-0.25

-0.20

-0.15

-0.10

-0.05

0 2000 4000 6000 8000 10000

Tem

per

atu

re(

Len

gth

No

rmal

ized

Inse

rtio

nLo

ss(d

B/m

)

Elapsed Time (min)

STFOC SMF28 (6m) 1550 nm

ISS (1m) 850 nm

ISS (3m) 850 nm

ISS (6m) 850 nm

Temperature

Fiber Cable Performance

40

60

80

100

120

140

0.05

0.10

0.15

0.20

0.25

Tem

per

atu

re(°

C)

Len

gth

No

rmal

ize

dIn

sert

ion

Loss

(dB

/m)

Flexlite (1m) 850 nm

Flexlite (3m) 850 nm

Flexlite (6m) 850 nm

-60

-40

-20

0

20

-0.15

-0.10

-0.05

0.00

0 500 1000 1500 2000 2500 3000

Tem

per

atu

re(

Len

gth

No

rmal

ized

Inse

rtio

nLo

ss(d

B/m

)

Elapsed Time (min)

Flexlite (1m) 1310 nm

Flexlite (3m) 1310 nm

Flexlite (6m) 1310 nm

Temperature

Insertion Loss change is slightly wavelength dependent

Preconditioned versusNon-Preconditioned

40

60

80

100

120

140

1.00

1.50

2.00

2.50

Tem

per

atu

re(°

C)

Inse

rtio

nLo

ss(d

B)

ISS 1m Preconditioned

ISS 3m Preconditioned

-50°C to 125°C, 2°C/min, 60 min dwell at extremes

Test conductedat 850 nm-60

-40

-20

0

20

40

-0.50

0.00

0.50

1.00

0 500 1000 1500 2000 2500 3000 3500 4000 4500 5000

Tem

per

atu

re(

Inse

rtio

nLo

ss(d

B)

Elapsed Time (min)

ISS 3m Preconditioned

ISS 6m Preconditioned

ISS 1m Nonpreconditioned

ISS 3m Nonpreconditioned

Temperature

Preconditioned versusNon-Preconditioned

40

60

80

100

120

140

15.00

20.00

25.00

30.00

35.00

Tem

per

atu

re(°

C)

Inse

rtio

nLo

ss(d

B)

SMF PEEK 1m Preconditioned

SMF PEEK 3m Preconditioned

-60

-40

-20

0

20

40

-5.00

0.00

5.00

10.00

15.00

0 500 1000 1500 2000 2500 3000 3500 4000 4500 5000

Tem

per

atu

re(

Inse

rtio

nLo

ss(d

B)

Elapsed Time (min)

SMF PEEK 3m Preconditioned

SMF PEEK 6m Preconditioned

SMF PEEK 1m Nonpreconditioned

SMF PEEK 3m Nonpreconditioned

Temperature

-50°C to 125°C, 2°C/min, 60 min dwell at extremes

Test conductedat 1550 nm

Summary

• Most fiber optic cables will shrink

• Fiber cables must be cut to length beforepreconditioning

• Thermal cycling is required to properly preconditionthe fiber cablethe fiber cable

• Temperatures will depend upon mission

• Number of cycles will depend upon cable

• This step early in the manufacturing process canmean the difference between mission success andfailure

Problems to Avoid

YOU DON’TWANT THISTO HAPPENTO HAPPEN

TO YOU

Fiber optic cable

Acknowledgements

Funding for this study provided by:NASA Electronic Parts and Packaging (NEPP) Program

http://nepp.nasa.gov

For additional information please see our websitehttp://misspiggy.gsfc.nasa.gov/photonics