Z. Ghassemlooy , H. Le Minh, and Wai Pang Ng Optical Communications Research Group
H. Le Minh, Z. Ghassemlooy, Wai Pang Ng and M. F. Chiang
description
Transcript of H. Le Minh, Z. Ghassemlooy, Wai Pang Ng and M. F. Chiang
Simulations of All-Optical Multiple-Input AND-Gate Based on Four Wave Mixing in a
Single Semiconductor Optical Amplifier
H. Le Minh, Z. Ghassemlooy, Wai Pang Ng and M. F. Chiang
Optical Communications Research Group, NCRLabNorthumbria University, Newcastle, UK
14th IEEE International Conference on Telecommunications
8th IEEE Malaysia International Conference on Telecommunications
Penang, Malaysia, 14th - 17th May 2007
ICT-MICC 2007ICT-MICC 2007
Presentation Outline
1. Introduction
2. SOA nonlinearities and FWM
3. Three-input AND gate based on SOA-FWM
4. Simulations
5. Summary
ICT-MICC 2007ICT-MICC 2007
Presentation Outline
1. Introduction
2. SOA nonlinearities and FWM
3. Three-input AND gate based on SOA-FWM
4. Simulations
5. Summary
ICT-MICC 2007ICT-MICC 2007
Photonic Network Transparency High-speed all-optical core router
Processing, switching and routing in optical domain high throughput
Solution: All-optical Boolean logic gates (AND, OR, XOR…)
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Introduction
Edge Router (Ingress/Egress) with 4-bit address XXXX
Core Router
1011
1010 0110
0111
Client Network
Client Network
1001
XXXX
Low-speed packet
Low-speed packet
High-speed packet
Core Network
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Presentation Outline
1. Introduction
2. SOA nonlinearities and FWM
3. Three-input AND gate based on SOA-FWM
4. Simulations
5. Summary
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SOA Nonlinearities
1. Cross gain modulation
2. Cross phase modulation
3. Four-wave mixing
SOA BPF (2)
1
2
Data
CW
Inverted data at 2
1 2
Data
CW
2
SOA1
SOA2
BPF (2)
1
2
1 – 2
SOA
1
2
1 2
21 – 2 22 – 1
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Presentation Outline
1. Introduction
2. SOA nonlinearities and FWM
3. Three-input AND gate based on SOA-FWM
4. Simulations
5. Summary
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3-inputs AND gate based on SOA-FWM (1)
Operation Principle M different inputs Xm at different M frequencies m
Output Y is “1” only when all the inputs are non-zeros
Ein Eout
WDM multiplexer
X1
X2
XM
SOA
1
2
M
o Y
X1 X2 … XM Y 0 x … x 0 x 0 … x 0 … … … … 0 x x … 0 0 1 1 … 1 1
x: 0 or 1 M-input AND gate
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3-inputs AND gate based on SOA-FWM (2)
Multi-tone Output N frequency components are generated:
Output Y is selected at o such that the component consists of all m contributions
2
)1(2
MMN
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Ein Eout
WDM multiplexer
X1
X2
XM
SOA
1
2
M
o Y
X1 X2 … XM Y 0 x … x 0 x 0 … x 0 … … … … 0 x x … 0 0 1 1 … 1 1
x: 0 or 1 M-input AND gate
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3-inputs AND gate based on SOA-FWM (3)
Frequency component generation from 3 input wavelengths Signal beatings 3 – 2, 3 – 1 and 2 – 1 will modulate signals
at 1, 2 and 3, thus resulting in 9 new frequency components
However, only three components contain information of all 1, 2 and 3. Those are: 1 + 2 – 3, 3 + 1 – 2 and 2 + 3 – 1.
1+2– 3
1+1–3 1+1– 2 2+2–3
3+1–2
2+2– 1
2+3–1
3+3–2 3+3–1
1 2
3 2S
2r
1+2– 3
1+1–3 1+1– 2 2+2–3
3+1–2
2+2– 1
2+3–1
3+3–2 3+3–1
1 2
3 2S
2r
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Eout
o Y X1 X2 … XM Y
0 x … x 0 x 0 … x 0 … … … … 0 x x … 0 0 1 1 … 1 1
x: 0 or 1
3-input AND gate based on SOA-FWM (4)
Filtering out o
Y could be selected from one of these components1 + 2 – 3
3 + 1 – 2 2 + 3 – 1
However, for high conversion efficiency, 2 + 3 – 1 is selected (positive detuning)
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3-input AND gate based on SOA-FWM (5)
Output power
Output power is given by
where GX is the SOA gain in X-polarisation, R() is
the conversion efficiency function (nonlinear)
1323X321out 2 RGPPPP
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3-input AND gate based on SOA-FWM (6)
Output Amplitude Modulation Ratio: the ratio of the
maximum value over the minimum value of the output
bits “1”
Output On/Off Contrast Ratio: the ratio of the
minimum value of output bits “1” and the maximum of
output bit “0”
min,1
max,1AM P
Pr
max,0
min,1on/off P
Pr
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Presentation Outline
1. Introduction
2. SOA nonlinearities and FWM
3. Three-input AND gate based on SOA-FWM
4. Simulations
5. Summary
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Simulations (1)
Parameters Values
X1 signal frequency - f1 193.1 1012 HzX2 signal frequency - f2 193.4 1012 HzX3 signal frequency - f3 194.1 1012 HzX1 pulse peak power - P1 2 mWX2 pulse peak power - P2 2 mWX3 pulse peak power - P3 2 mWPulse-width 5 psOutput filter frequency – f0 194.4 1012 Hz (at f0 = f2 + f3 – f1)Filter bandwidth - B0 140 109 Hz
Parameters Values
Laser chip length 600.0 10-6 mActive region width 3.0 10-6 mActive region thickness 40.0 10-9 mConfinement factor 0.56Group effective index 3.7Material linewidth enhancement factor 3.0Differential refractive index -1.11 10-26 m3
Linear material gain coefficient 3.0 10-20 m2
Transparency carrier density 1.5 10-24 m-3
Nonlinear gain coefficient 1.0 10-23 m3
Nonlinear gain time constant 200.0 10-15 sCarrier capture time constant 70.0 10-12 sCarrier escape time constant 140.0 10-12 sGain peak frequency 196.0 1012 HzGain coefficient spectral width 1.0 1013 HzPopulation inversion parameter 2.0Initial carrier density 1.0 1024 m-3
Injection DC current 200 mA
Simulation parameters SOA parameters
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Simulations (2)
VPI simulation schematic
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Simulations (3)
AND operation
X1
(1 0 1 0 1 1 1 1 0 1 )
X2
(0 1 1 0 1 1 1 0 1 1 )
X3
(0 1 1 0 0 1 1 0 1 1 )
Y
(0 0 1 0 0 1 1 0 0 1 )
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Simulations (4)
Two/three-input AND gate performance (10 Gbit/s)
- - - 2-input AND gate 3-input AND gate Pout rAM ron/off
• Output power: linearly dependent on the input power
• Amp. modulation ratio (rAM): the amplitude variation is small ~ 2 dB
• On/off contrast ratio (ron/off): in a range of 14 - 22 dB
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Simulations (5)
Two/three-input AND gate performance (10, 20 and 40 Gbit/s)
- - - 2-input AND gate 3-input AND gate Pout rAM ron/off
• Output power: being reduced at high speed due to slow SOA gain recovery
Therefore
• Amp. modulation ratio and On/off contrast ratio are reduced
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Presentation Outline
1. Introduction
2. SOA nonlinearities and FWM
3. Three-input AND gate based on SOA-FWM
4. Simulations
5. Summary
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Summary
SOA-FWM AND gate features– Multiple-input logic AND gates– Simple implementation– Low power consumption– Integration capability (SOA size ~ m)
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SOA-FWM AND gate issues– Low wavelength conversion ratio– Speed is limited by SOA gain recovery
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Acknowledgement
Northumbria University for sponsoring this research
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Thank you!
Any Questions?
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