high-power high-efficiency photodiode for advanced ligo ligo-g010359-00-z
DESCRIPTION
High-Power High-Efficiency Photodiode for Advanced LIGO LIGO-G010359-00-Z. David Jackrel Ph.D. Candidate- Dept. of Materials Science & Eng. Advisor- Dr. James S. Harris August 14 th , 2001. Outline. Introduction Photodiode Specifications Device Structure & Materials - PowerPoint PPT PresentationTRANSCRIPT
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High-Power High-Efficiency Photodiode for Advanced LIGO
LIGO-G010359-00-Z
David Jackrel
Ph.D. Candidate- Dept. of Materials Science & Eng.
Advisor- Dr. James S. Harris
August 14th, 2001
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Outline
Introduction Photodiode Specifications Device Structure & Materials
Experimental Results DC Response RF Response
Development Plan InGaAs GaInNAs
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Photodiode Specifications?
Parameter LIGO I Advanced LIGO
Steady-State Power 0.6 W 1~10 W
Operating Frequency 29 MHz 100 kHz
~ 180 MHzQuantum Efficiency 80% 90%
Detector Design
Bank of 6(+) PDs 1 PD
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P-I-N Device Characteristics
Large E-field in I- region
Depletion Width Width of I- region
RC time constant
Tuned to a specific
1
IW
IsJ
Js
WAKC
CR
/0
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Heterojunction Band Gap Diagram
= 1.064m h = 1.17eV
Absorption occurs in i-region
InAlAs Optically transparent to 1.06m radiation
N-layer:
In.22Al.78As
Eg2=1.8eV
P-layer:
In.22Al.78As
Eg2=1.8eV
I-layer:
In.22Ga.78As
Eg1=1.1eV
n-
i-
p-
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Rear-Illuminated PD Advantages
Conventional PD Adv. LIGO Rear-Illuminated PD
High Power High Speed Linear
Response
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InGaAs/GaAs PD Structure
•MBE
•GaAs Substrate
•InGaAs for i-layer
•InAlAs for the n- and p- layers
•Graded Buffer layer
•AR coating & Au/Pt contacts
2 m
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III-V Lattice Constants and Band Gaps
InAlAs and InGaAs well lattice matched
InAlAs much wider band gap
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TEM Images of Confined Dislocations
Device Layers:
-few dislocations
Graded Buffer:
-many dislocations
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Nd:YAG (NPRO) PD Test Setup
NPRO
(800mW)
PDPower
Meter
Power
Control
RF Amplitude
Modulator
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Quantum Efficiency: #673
Avg. Quantum Efficiency v Reverse Biasy = 0.0045e-0.7534x
R2 = 0.9808
0.0%
10.0%
20.0%
30.0%
40.0%
50.0%
60.0%
70.0%
80.0%
90.0%
100.0%
-8 -7 -6 -5 -4 -3 -2 -1
Bias (V)
QE
(%
)
30%Loss
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QE: Power & Bias Effects
#673 Edge, Popt=1.00mW, 2.57mW, 5.18mW
0.00%
10.00%
20.00%
30.00%
40.00%
50.00%
60.00%
70.00%
-7 -6 -5 -4 -3 -2 -1 0
V (Volts)
QE
(%
)
QE (%) 5.18mW
QE (%) 2.57mW
QE (%) 1.00mW
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DC Response Linearity: #673
Photocurrent, Vb = -6.5Vy = 0.5729x - 0.0931
R2 = 0.9993
0
5
10
15
20
25
0 5 10 15 20 25 30 35 40
P optical (mW)
I ph
(m
A)
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RF Response: 3dB Bandwidth
~4MHz, 3dB-Bandwidth
~5nF Capacitance
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C-V Characteristics (#673)
depletion width 1.44 m ~2.16m
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InGaAs Development Plan
Goals: by Sept. 2002…
90% QE
Thin substrates to 50m-100m
Maximize Bandwidth
Optimize illuminated area
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GaInNAs Lattice-Matched to GaAs
GaInNAs- Adv LIGO
InGaAs- LIGO I PD
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Conclusion
Introduction Photodiode Specifications Device Structure & Materials
InGaAs RI PIN PD
Experimental Results DC Response
70% QE RF Response
4MHz 3-dB Bandwidth
Development Plan InGaAs GaInNAs