4/27 radiation effects in active optical components robert a. reed, ken label, janet barth, henning...
TRANSCRIPT
4/27
Radiation Effects in Active Optical Components
Robert A. Reed, Ken LaBel, Janet Barth,
Henning Leidecker, Allan Johnston,
Paul Marshall and Cheryl Marshall
4/27
Radiation Effects and Analysis Group
4/27
Outline
• Introduction to radiation effects in optical components
• Radiation environment
• optical components
• Radiation induced transients in optical components
• Radiation induced degradation mechanisms in optical components
• Summary
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Radiation-Induced Effects in Optical Components
0123456
0 100 200 300 400 500 600(ns)
(V)
Single Event Transient
00.51.01.52.02.5
0 4x1010
Fluence (p/cm2)
CT
R
8x1010 12x1010
Displacement Damage
02468101214
0 20 40 60 80 100 120
Dose (kRad(Si))
I-lit
e (
mA
)
Total Ionizing Dose
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Radiation Environments
• Heavy Ion LET Spectra
• Total Ionizing Dose
• Proton Spectra
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Heavy Ion
1.00E-12
1.00E-11
1.00E-10
1.00E-09
1.00E-08
1.00E-07
1.00E-06
1.00E-05
1.00E-04
1.00E-03
1.00E-02
1.00E-01
1.00E+00
1.00E+01
1.00E+02
1.00E+02 1.00E+03 1.00E+04 1.00E+05 1.00E+06
LET (MeV-cm^2/g)
Inte
gra
l F
lux
(m2
-s-s
r)-1
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Total Ionizing Dose
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Proton Environment
1.E-01
1.E+00
1.E+01
1.E+02
1.E+03
1.E+04
1.E+05
1.E+06
1.E+07
1.E+08
1.E+09
1.E+10
0.01 0.10 1.00 10.00 100.00 1000.00
Energy (MeV)
Dif
fere
ntia
l Pro
ton
Flu
ence
(#/
cm2 /y
ear/
MeV
)
1.E-01
1.E+00
1.E+01
1.E+02
1.E+03
1.E+04
1.E+05
1.E+06
1.E+07
1.E+08
1.E+09
1.E+10
Rat
io o
f N
IEL
at
E t
o N
IEL
at
195
MeV
AURORAL: I=90 deg, H=1000/6000 kmGTO: I=18 deg, H=360/36000 kmMEO: I=51 deg, H=10000/10000 kmEOS: I=81 deg, H=705/705 kmHST: I=29 deg, H=600/600 kmRelitive Damage to 195 MeV protons
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Equivalent Proton Fluence for Displacement Damage
1.E+08
1.E+09
1.E+10
1.E+11
1.E+12
0 50 100 150 200 250
Proton Test Energy (MeV)
Equ
ival
ent
Flu
ence
for
1 Y
ear
Mis
sion
(p/
cm2 )
AURORAL: I=90 deg, H=1000/6000 km
GTO: I=18 deg, H=360/36000 km
MEO: I=51 deg, H=10000/10000 km
EOS: I=81 deg, H=705/705 km
HST: I=29 deg, H=600/600 km
13 NiRad(Si)
0.12 NiRad(Si)
0.09 NiRad (Si)
3.0 NiRad(Si)
2.1 NiRad(Si)
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Active Optical Components
• Optical coupling of two electrical circuits with an optical transmitter and an optical receiver.– LEDs, Phototransistors, photodiodes, etc...
• Optocoupler is one type of optical components– CTR = Io/ If
LEDDETECTOR
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Radiation-Induced Effects in Optical Components
0123456
0 100 200 300 400 500 600(ns)
(V)
Single Event Transient
00.51.01.52.02.5
0 4x1010
Fluence (p/cm2)
CT
R
8x1010 12x1010
Displacement Damage
02468101214
0 20 40 60 80 100 120
Dose (kRad(Si))
I-lit
e (
mA
)
Total Ionizing Dose
4/27
0
1
2
3
4
56
0 100 200 300 400 500 600
(ns)
Am
plit
ud
e (V
)
A sample SET from an HP QCPL-6731 Optocoupler
Single event transients induced in photodetector can be passed to circuitry that follows the optocoupler if the amplification stage recognizes the SET as a valid signal
4/27
Ground Based Single Event Transient Measurements
0.0E+00
2.0E-08
4.0E-08
6.0E-08
8.0E-08
1.0E-07
1.2E-07
30 80 130 180 230 280Proton Energy (MeV)
Cro
ss-S
ecti
on (
cm2 /d
evic
e)
0 degrees85 degrees87.5 degrees90 degrees92.5 degrees95 degrees
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Radiation-Induced Effects in Optical Components
0123456
0 100 200 300 400 500 600(ns)
(V)
Single Event Transient
00.51.01.52.02.5
0 4x1010
Fluence (p/cm2)
CT
R
8x1010 12x1010
Displacement Damage
02468101214
0 20 40 60 80 100 120
Dose (kRad(Si))
I-lit
e (
mA
)
Total Ionizing Dose
4/27
Total Ionizing Dose Degradation of Phototransistor
4/27
Total Ionizing Dose Degradation of LED
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Radiation-Induced Effects in Optical Components
0123456
0 100 200 300 400 500 600(ns)
(V)
Single Event Transient
00.51.01.52.02.5
0 4x1010
Fluence (p/cm2)
CT
R
8x1010 12x1010
Displacement Damage
02468101214
0 20 40 60 80 100 120
Dose (kRad(Si))
I-lit
e (
mA
)
Total Ionizing Dose
4/27
Optocoupler Current Transfer Ratio Degradation with Proton Fluence
0.0
0.5
1.0
1.5
2.0
2.5
0.0E+00 2.0E+10 4.0E+10 6.0E+10 8.0E+10 1.0E+11 1.2E+11
Fluence (p/cm2)
CT
R
2.5 mA
4.1 mA
7.3 mA
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DC/DC Power Converter that Contains an Optocoupler
0
5
10
15
20
25
0.0E+00 4.0E+10 8.0E+10 1.2E+11 1.6E+11
Fluence (Protons/cm2)
Vo
ltag
e (V
) 9603
0650
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LED Data from the Early 80’s
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Various Optocoupler Results
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Observed Properties of a “good” optocouplers
• Single Event Transient– Observed in devices that operate at > 5MhZ– Circuit filtering is possible
• Total Ionizing Dose– Shielding may help reduce TID (WARNING)
• Displacement Damage– Not Amphoterically doped– LED wavelength <800nm– Maximize LED drive (WARNING)– Operation of phototransistor in saturation
•RADIATION RESPONSE IS KNOWN
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SUMMARY
• Evaluation of three radiation induced effects is important for optical components links– SET, TID and Displacement Damage
• Unable to predict radiation response from manufacture information
• Data is available on some optical components
• Radiation testing at off site proton facility– Simultaneous evaluation of SET, TID and Displacement Damage
• Some optical components perform very well in the space radiation environment