march 30, 2004nasa goddard space flight center optical assemblies for space environments:...

March 30, 2004 NASA Goddard Space Flight Center

Optical Assemblies for Space Environments: Characterization of W.L.Gore Flexlite with Diamond AVIMS

for Space Flight Environments

Melanie N. Ott

Sigma Research and Engineering/

NASA Goddard Space Flight CenterMore information: 301-286-0127, [email protected]

URL: nepp.nasa.gov/photonics

misspiggy.gsfc.nasa.gov/photonics


Optical Assemblies for Space Environments: Characterization of

W.L.Gore Flexlite with Diamond AVIMSfor Space Flight Environments

Melanie N. Ott

Sigma Research and Engineering/

NASA Goddard Space Flight CenterMore information: 301-286-0127, [email protected]

URL: nepp.nasa.gov/photonics

Technical Team: Shawn Macmurphy, Marcellus Proctor, Patricia Friedberg


Photonics Manufacturing and Testing LabParts, Packaging and Assembly Technologies OfficeNASA GSFC, Code 562


Outline• MLA Requirements & Components

• Characterization plan

• Materials Study Results

• Vibration Testing & Results

• Thermal Testing & Results

• Radiation Parameters

• Radiation Testing Results

• Conclusions


MLA Requirements• Large diameter optical fiber, 200 and 300 micron, NA of .22 for use at 1064 nm.

• High performance assembly;

• Low insertion loss (< 0.4 dB)

• Repeatability.

• Stability in harsh environment

- thermal, vibration and radiation.

• Non-outgassing components.

• Assemblies 26.1 inches long used for beam delivery system, not interconnected.

Parts selection to meet requirements: • Diamond AVIMs with custom ferrule drilling, D-6201.1

• Part # E070040095VNAS1 Ferrule custom drilled for 220 fiber.

• Part # E070040095VNAS2 Ferrule custom drilled for 330 fiber.

• Part # 070015048V001, Hytrel boots.

• W.L.Gore, Flexlite simplex cable, FON1173, FON1174

• Polymicro Technologies optical fiber,

• FIA200220500, 200 micron, acrylate, .22 NA, step index

• FIA300330500, 300 micron, acrylate, .22 NA, step index

• Epoxy, Epo-Tek 353ND.


AVIMs and Flexlite AssemblyTerminations performed to NASA-STD-8739.5 and procedure 562-WI-8700.2


Mercury Laser Altimeter


Characterization Plan All testing conducted: recorded before and after optical performance data

as well as in-situ optical data.• Vacuum Outgassing,

– All materials must pass ASTM-E595. • Vibration Induced Effects

– Verified survival and operational ability during launch using typical launch parameters for small box components.

– 3 minutes per axis, 14.1 grms total, 3 assemblies tested.• Thermal Induced Effects

– -30°C to +50 °C, 90 cycles, last 42 monitored, (tests are conducted at 10°C higher than expected environmental extremes).

– 25 minute soak, 2 °C/min ramp rates.• Radiation Effects

– Space flight environments from GSFC are less than 1 rad/min and more typically less than 0.1 rads/min. Two dose rates used to possibly provide a model for extrapolation to lower dose rates.

• 11.2 rads/min for lower dose rate, 22.7 rads/min for higher dose,• Up to 30 Krads while maintaining a cold temperature of –20° C. • Actual projected dose rate for MLA: 16.44 rads/day, .685 rads/hour, .011 rads/min


Materials Results, nonmetallic parts

• Cable- Flexlite passed when tested previously in configuration during development of ICESAT (GLAS) with acrylate coated fiber.

- Cable does require preconditioning for thermal stability 8 cycles, 60 min @ 60°C, 25 min @ -20°C, < 2°C/min

• Connector BootsHytrel 8068 require de-gas preconditioning, 102 to 1 Torr, 140°C, 24 hours.Once preconditioned, ASTM-E595 results were:0.48 % TML, 0.10% CVCM.

• EpoxyEpoTek 353ND is contained in GSFC outgassing database.


Cable Designations and Initial Visual Inspection

Assembly Code Side A Side B

MP1

MP2

MP3

Pre-environmental Testing Visual Inspection

MPX Test assemblies were made of two AVIMS/AVIMS interconnected with an AVIMS adapter, each ~ 24 inches long.

Presented above are end face pictures of the mated sides that were exposed to environmental testing


Vibration Testing

3 minutes/axis, 14.1 grms total, 3 axis test

X

Y ZZ axis orientation X axis orientation


Vibration Parameters for Test

Frequency (Hz) Protoflight Level

20 0.026 g2/Hz

20-50 +6 dB/octave

50-800 0.16 g2/Hz

800-2000 -6 dB/octave

2000 0.026 g2/Hz

Overall 14.1 grms

Random Vibration Profile ParametersBased on EO-1 and MLA specifications

3 minutes/axis, 14.1 grms total, 3 axis test for mated pair


Vibration Test Results: X axis MP1

Optical Losses During X axis Vibration Test on MP1

-5.000E-04

0.000E+00

5.000E-04

1.000E-03

1.500E-03

2.000E-03

2.500E-03

3.000E-03

3.500E-03

1 92 183

274

365

456

547

638

729

820

911

1002

1093

1184

1275

data point

Inse

rtio

n L

oss

(d

B)

MP1-Xaxis


Vibration Test Results: Y axis MP1

Optical Losses During Y Axis Vibration Test on MP1

-5.0000E-04

0.0000E+00

5.0000E-04

1.0000E-03

1.5000E-03

2.0000E-03

2.5000E-03

1 85 169

253

337

421

505

589

673

757

841

925

1009

1093

1177

Data point

Inse

rtio

n L

oss

(d

B)

MP1-Yaxis


Vibration Test Results: Z axis MP1

Optical Losses During Z Axis Vibration Test for MP1

-1.000E-03

-5.000E-04

0.000E+00

5.000E-04

1.000E-03

1.500E-03

2.000E-031 82 163

244

325

406

487

568

649

730

811

892

973

1054

1135

Data point

Inse

rtio

n L

oss

(d

B)

MP1-Zaxis


Vibration Test Results Summary

Assembly Set

Vibration Test Axis

Max Induced Insertion Loss

Final Change in Insertion Loss Post

Testing

MP1 X 0.0031 dB 0.0028 dB

MP1 Y 0.0024 dB 0.0012 dB

MP1 Z 0.0015 dB 0.0006 dB

MP2 X -0.0002 dB* -0.0027 dB *

MP2 Y -0.0006 dB* -0.0012 dB *

MP2 Z 0.0027 dB 0.0004 dB

MP3 X -0.0005 dB* -0.0017 dB *

MP3 Y 0.0004 dB 0.00 dB

MP3 Z 0.0003 dB* -0.002 dB **Indicates an increase in power post vibration testing

No endface damage was detected during post vibration visual inspection.


Thermal Testing -30°C to +50 °C, 90 cycles, last 42 cycles monitored optically.

Program malfunction caused lack of data collected during the first 48 cycles.


Thermal Testing ResultsInsertion Loss for MP1 During 42 Thermal Cycles

vs. Time

-6.00E-02

-4.00E-02

-2.00E-02

0.00E+00

2.00E-02

4.00E-02

6.00E-02

8.00E-02

1

628

1255

1882

2509

3136

3763

4390

5017

5644

Time (min)

0 100 200 300 400 500 600 700 800 900 1000-0.04

-0.03

-0.02

-0.01

0

0.01

0.02

0.03

0.04

0.05

Ins

ert

ion

Lo

ss

(d

B)

Time (min)

0 100 200 300 400 500 600 700 800 900 1000

-30

-20

-10

0

10

20

30

40

50

60

Te

mp

era

ture

(d

eg

ree

s C

)

Time (min)

Insertion Loss of MP1 with Temperature vs. Time for 7 cycles

Insertion loss for MP1During 68th to 75th cycle (Red) with temperature (Black). Insertion loss increases with decreasing temperature.

Example of data collected for all assembliesMP1 during 42 cycles (after initial 48 cycles unmonitored)


Thermal Testing Results SummaryAssembly

SetΔ insertion loss during

testing

Overall Change in loss post testing, 90

cycles

Max insertion loss during

testing

Visual Inspection post test side A

Visual Inspection post test side B

MP1 0.09 dB -0.044 dBpower increase

0.058 dB

MP2 0.07 dB -0.015 dB power increase

0.037 dB

MP3 0.04 dB -0.035 dB power increase

0.024 dB


Radiation Test Parameters

Tested up to 30 krads in Cobalt 60 chamber:• 10 m of FON1173 (200 micron core fiber) • 10 m of FON1174 (300 micron core fiber)• High dose rate 22.7 rads/min• Low dose rate 11.2 rads/min• While maintaining at temperature of -20°C.• Monitored optical power at 850 nm @ < 1 micro watt of power.


Radiation Results for High Dose Test

0 0.5 1 1.5 2 2.5 3 3.5

x 104

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9High Dose Rate Rad-Induced Attenuation for 200 (red) & 300 (blue) Flexlite Cable

Ra

dia

tio

n I

nd

uc

ed

Att

en

ua

tio

n (

dB

)

Total Dose (rads)

300 micron

0.818 dB

0.892 dB

200 micron

Induced attenuation for both 200 (red), and 300 (blue) micron cable up to 30 krads

22.7 rads/min10 meters of cable


Radiation Results for Low Dose Test

0 0.5 1 1.5 2 2.5 3 3.5

x 104

0

0.2

0.4

0.6

0.8

1

1.2

1.4Low Dose Rate Rad-Induced Attenuation for 200 (red) & 300 (blue) Flexlite Cable

Ra

dia

tio

n I

nd

uc

ed

Att

en

ua

tio

n (

dB

)

Total Dose (rads)

300 micron

200 micron

1.024 dB

0.917 dB

Induced attenuation for both 200 (red), and 300 (blue) micron cable up to 30 krads

11.2 rads/min10 meters of cable

Small “glitch” at ~ 20 krads due to fire alarm closing chamber shutter


Radiation Results SummaryPart # Type OF

(microns)

Dose rate Atten. @ 30 krads

Ave. temp during testing

Expected atten. 26.1 inches @ 30 krads

FON1173 200 11.2 rads/min 1.024 dB -24.1°C 0.068 dB

FON1174 300 11.2 rads/min 0.917dB -24.1°C 0.061 dB



• Results for 200 and 300 micron fiber are ~ identical.• Results for high and low dose rate tests for both fibers also ~ identical.• Extrapolation model can not be used without further experimentation.• Dose rate differences are attributed with difference in thermal environment.


Conclusions• In general, Flexlite and AVIMs assemblies performed with superiority in

comparison to other studies conducted in the past (nepp.nasa.gov/photonics for more information).

• Vibration and Thermal Conclusions: Final change in insertion loss after both vibration and thermal testing is as follows:- MP1, -.04 dB, resulting power increase

- MP2, -.02 dB, resulting power increase

- MP3, -.04 dB, resulting power increase

• Radiation Conclusions: - Since extrapolation method can not be used best assumption is by usage

of lower dose rate results. Actual MLA dose rate will be .011 rads/min.- Using 11.2 rads/min results, expected losses will be less than .07 dB for

each 26.1 inch assembly at –20ºC at a total dose of 30 krads under “dark conditions” or without power enough to provide photobleaching annealing effects.

- Both FON1174 and FON1173 perform identical.

Post all environmental testing: MP1, 0.03 dB; MP2, 0.05 dB; MP3, 0.03 dB


AcknowledgementsSpecial thanks to NASA Electronic Parts and Packaging Program &

MESSENGER, Mercury Laser Altimeter Program for funding of this work.Additional thanks to

Dr. Henning Leidecker (always!)Darryl Lakins

Dr. Charles BarnesPhillip Zulueta

Luis A Ramos-Izquierdo Arlin Bartels

For resources and program management support

For more information see the websites:http://nepp.nasa.gov/photonicshttp://misspiggy.gsfc.nasa.gov/photonics

Special thanks to the WebEx team for making this possibleJeannette Plante & Carl Szabo

march 30, 2004nasa goddard space flight center optical assemblies for space environments:...

Documents

space environments

govphotonics slide

diamond avims

gore flexlite

characterization of

optical performance

patricia friedberg slide

situ optical data