SOFI
WP2: Applications of Silicon-Organic Hybrid
(SOH) and Device Specification
Networks and Optical Communications group – NOC
Ioannis Tomkos, Arvind Mishra
presented by Dietmar Korn, Karlsruhe Institute of Technology
1
NOC group - AIT
www.ait.edu.gr
SOFI
Outline
 Orientation
• Objectives
• Achievements
 Possible SOH Applications
 Target Applications
• Specifications
 Simulations
• Electro-optical, Chi(2) related
• All-optical, Chi(3) related
2
NOC group - AIT
www.ait.edu.gr
SOFI
WP2 – Task & Objectives
 Task 2.1 Definition of application and device
specifications [M1 – M12]
 Task 2.2 Modelling of devices and system for
communications applications [M12 – M36]
 Task 2.3 Value analysis in terms of cost and green
aspects [M24 – M30]
 Task 2.4 The evaluation of the silicon-organic
hybrid technology for the realization of disruptive
components by exchanging the organic cladding
materials [M1 – M36]
3
NOC group - AIT
www.ait.edu.gr
SOFI
WP2 - Objectives Task 2.1 (2010)
 To define the applications for advanced network functionalities in terms of high
data rate, low cost and power consumption.
 Define the device specifications of a waveguide phase modulator and an
integrated MZI modulator.
 To define a device and system reference scenario that will be used for the
performance evaluation of the developed components with respect to the
identified applications.
Milestone 2.1: Decision on implementation of devices based on the electro-optic modulation
applications and material properties (M3) [Completed]
Milestone 2.2: Definition of a system environment with respect to the network applications (M4)
[Completed]
Deliverable 2.1: Definition of potential applications and system environment.
First device specifications are issued (M6) [Completed]
4
NOC group - AIT
www.ait.edu.gr
SOFI
Applications of
Silicon-Organic Hybrid Technology
• Electro-optic signal processor
Material properties
List of applications
Target system scenarios
[Modulator, QPSK, DP-QPSK, OFDM]
– Device specification
– System specifications
• All- optical signal processor
Nonlinear material parameters
List of applications
 Possible system scenarios
Device specification
5
NOC group - AIT
WP1
Project Management
WP3
Silicon Chip Desing &
Fabrication
WP4
Organic Material
Fabrication, Deposition &
Chip Functionalization
WP2
Spezifications,
Applications
WP5
RF Packaging, Pigtailing
and Testing
WP6
Exploitation, Dissemination, Publication
www.ait.edu.gr
SOFI
Electro-optic material properties
of SOH
Very large second order nonlinear (Chi-2)
electro-optic interaction
Organic Material
EO coefficient
Vpi
Polymer-M1@GO
r33= 80 pm/V @ 1550nm
1 Volt
OH-1@ RB
r11= 50 pm/V @1550nm
1.5 Volt
6
NOC group - AIT
Ultra high speed operation
www.ait.edu.gr
SOFI
Identified Electro-Optic Applications
of SOH Technology
High speed optical communication system
As a Phase/ MZM modulator [10 – 100 GHz]
–
–
–
–
As a low energy pulse carver for RZ, RZ DPSK, RZ DQPSK
NRZ, RZ, Duo-binary modulation formats
I-Q modulator for DQPSK/ QAM, OFDM
Low energy subcarrier generation for OFDM
Demodulators for M-PSK, DPSK, DQPSK, QAM, OFDM
– Passive structures will be put on the chip
WDM de-multiplexers
– Can be realized by cascading multiple tunable micro-ring resonators filled with
SOH material to provide flexible FSR
Additional applications



7
Microwave photonics
Ultra short pulse generator
Arbitrary optical waveform generation
NOC group - AIT
www.ait.edu.gr
SOFI
Target Applications
Modulators for data transmission ( Vpi < 3 V) operating at 10 - 100 Gbd
 Phase and MZM modulator
 I-Q QPSK modulator
 Integrated RZ pulse carver with DQPSK modulators
 Possibility to realize dual polarization modulators for QPSK modulators
Modulators for
 Modulators for Microwave photonics
 Comb line generation / OFDM signal generation
Chemical sensing application (Bio-chip based optical sensing)
8
NOC group - AIT
www.ait.edu.gr
SOFI
Initial SOFI Modulator Specifications
Modulators ( Vpi < 3 V)
•
•
•
•
•
9
Phase Modulator
Intensity Modulator
I-Q QPSK/ OFDM modulator
Integrated RZ pulse carver
with DQPSK modulators
Possibility to realize dual
polarization QPSK modulators
 Industry interest
NOC group - AIT
Modulator specification Minimum Best case Estimated from
experiments
RF Vpi
7V
1V
5V
Extinction ratio
10 dB
30 dB
-
-Losses (without insertion)
8dB
4 dB
15 dB
Polarization Isolation
1 dB
20-30 dB
20 dB
(as expected)
Symbol rate (Gbaud/s)
12.5
100
10
Data rate (Gbit/s)
NRZ/RZ/Duobinary/BPSK
QPSK/DQPSK
8-PSK
16-QAM
32-QAM
12.5
25
37.5
50
100
100
200
300
400
800
Need experiment
Group velocity dispersion
-
-
Need experiment
Operating wavelength
range
C band
C
band
-
Wavelength dependent loss
< 2 dB
< 0.2
dB
Maximum Operating
temperate
850C
2500C
www.ait.edu.gr
SOFI
Simulation Plans (Task 2.2)
Target Simulation Plan as per deliverable D2.1
– QPSK transmission at 56 Gbit/s and digital coherent detection
– DP-QPSK transmission at 112 Gbit/s and digital coherent detection
– Multi-channel QPSK-OFDM transmission
Current activities
– QPSK/DQPSK transmission at 56 Gbit/s and digital coherent
detection
– 100 Gbit/s OFDM systems
– Novel and cost-effective subcarrier generation
– 100 Gbit/s Duobinary-OFDM signal generation
– OFFT filtering and direct detection
10
NOC group - AIT
www.ait.edu.gr
SOFI
Target Systems Scenarios (1):
50 Gbit/s QPSK Transmission
and Coherent Detection
I-Q Modulator
I
Single polarization 50 Gbit/s
•
•
Transmitter
 I-Q modulators with 25 Gbd/s
 Coherent
 Real time processing
Out
 Dispersion compensation
 Optical PMD compensation
 Compensation of nonlinearities
 System impairments
NOC group - AIT
FEC
Decoder
90
9000
PD1
Carrier
recovery
 System performance analysis
11
MZM
MZM
Q
Receiver
Equalizer
MZM
MZM
LD1
Fiber
•
Data QPSK
Coder
DSP
Clock
recovery
retiming
I
-
PD2
LO
ADC
PD3
90
9000
Q
-
PD4
Equalizer
Coherent detection




Symbol rate = 28 Gs/s
Linewidth Tx = LO = 100 kHz
Extinction ratio = 25 dB
Tx power = 5 mW
www.ait.edu.gr
SOFI
Target Systems Scenarios (1):
Dependence on Design Parameters
@Transmitter
@Receiver
@Communication channel
I/Q optical power imbalance
Gain imbalance at the modulator drivers
Path delay between I and Q
Phase error of transmitted
I and Q
Impact of Laser linewidth and RIN
Modulator bias
Pre-distortion or pre-filtering
Launch power
Coherent cross talk
Split ratio imbalance
Power optimization of Local
oscillator
Role of narrow line width local
oscillator
Optimization of Equalizer
Group velocity dispersion
Polarization mode
dispersion
Fiber nonlinearities:
FWM, SPM, XPM, etc.
-35
0.25
-37
0.2
0.15
-39
0.1
-41
0.05
-43
0
10
15
20
25
30
Extinction Ratio (dB)
35
40
Rx Sensitivity (dBm)
56Gbit/s QPSK, B2B, with DSP
Split Ratio
Imbalance
Rx @SER 10-3
56Gbit/s QPSK, B2B, with DSP
-29
-34
SER@10-3
-39
SER@10-9
-44
0
0.5
1
1.5
2
Drive amplitude Imbalance I-Q (dB)
12
NOC group - AIT
www.ait.edu.gr
SOFI
Target Systems Scenarios (1):
Maximum Reach Fiber Length
DQPSK
Co-QPSK
QPSK transmission is possible @ SER 10-3 upto
1280 km of fiber in dispersion managed system
13
NOC group - AIT
www.ait.edu.gr
SOFI
Target Systems Scenarios (2):
100 Gbit/s DP-QPSK Transmission
and Coherent Detection
QPSK
coder
100 Gbit/s DP-QPSK
Data
•
•
FEC
Encoder
TM
900
CW
LD
PBS
PBS
Transmitter
 I-Q modulators with 25 Gbaud/s
 Dual polarization
– DP-QPSK has potential industry interest
Receiver
 Coherent
 Real-time Processing
Data
FEC
De-coder
P/S
QPSK
coder
DSP
Clock
recovery
retiming
ADC
Balance
Detection
CW
LD
TE
TM
900
Hybrid
PBS
PBS
Equalizer
Carrier
recovery
NOC group - AIT
900
Equalizer
Carrier
recovery
14
S/P
TE
DSP
Clock
recovery
retiming
ADC
Balance
Detection
900
Hybrid
www.ait.edu.gr
Target systems scenarios (3):
OFDM signal generation/transmission and
detection
SOFI
100 Gbit/s QPSK OFDM
QPSK
25 Gbd/s
25 GHz
~
Laser
MZM
I-Q mod
φ
I-Q mod
φ
I-Q mod
φ
I-Q mod
φ
100 Gbit/s
QPSK-OFDM
Equalizer
Optical
FFT
90 deg
Hybrid
LO
Balance
Detection
ADC
Clock
recovery
retiming
Carrier
recovery
DSP
FEC
Decoder
Data rates: 100 Gbit/s
No of subcarrier = 4
Symbol rate = 25 Gbaud/s
Channel spacing = 50 GHz
Spectral efficiency (b/s/Hz) = 2
15
NOC group - AIT
www.ait.edu.gr
SOFI
Novel Comb-line Generation
Scheme
Since wave frequency (10 GHz)
VPI -Simulated comb-spectra
Since wave frequency ( 2x 10GHz)
Advantage
Spectral flatness
0.9 dB
1.
2.
3.
4.
16
NOC group - AIT
Simple and cost-effective
Require drive voltage < ~Vpi = 8 + 1 comb lines
Doesn’t require additional electrical diplexer or
Modulators
Can generate more comb lines with larger drive
voltages than Vpi
www.ait.edu.gr
SOFI
Target Systems Scenarios (3):
100 Gbit/s Duobinary-OFDM
100 Gbit/s Duobinary-OFDM
Transmitter
12.5 Gb/s
 Data rates 100 Gbit/s
 No of subcarrier = 8
 Symbol rate = 12.5 Gbaud/s
 Channel spacing = 100 GHz
 Spectral efficiency (b/s/Hz) = 1
100 Gb/s OFDM signal
0.01 nm@RBW
0.01 nm@RBW
17
NOC group - AIT
www.ait.edu.gr
SOFI
•
Summary: Simulations Performed
and Platform Built
Simulation platform built for transmission system performance
analysis off 56Gbit/s coherent QPSK
– Digital coherent receiver
– Dual-polarization capability- in progress
18
•
Combline generation schemes
•
Simulation platform for system performance analysis of 100
Gbit/s Duobinary OFDM
NOC group - AIT
www.ait.edu.gr
SOFI
Future Simulations Planned

Performance of 56 Gbit/s QPSK with DSP without dispersion
management system
• WDM system

Performance of 112 Gbit/s DP-QPSK with/ without DSP with dispersion
management system
• Single channel
• WDM system

Experimental validation of 100 Gbit/s duobinary OFDM results

Simulation and Experiments for 100 Gbit/s QPSK OFDM
19
NOC group - AIT
www.ait.edu.gr
SOFI
Rx using OFFT and direct detection
100 Gbit/s Duobinary-OFDM
Receiver with direct detection
Fiber span 40 km
After 3x 40 km
0.01 nm@RBW
•
•
20
Subcarrier data signals are separated by OFFT
Peak to average ratio is very large, which need to be minimized within ± 2dB
• System optimization is underway
NOC group - AIT
www.ait.edu.gr
SOFI
Initial Result:
100 Gbit/s Duobinary-OFDM
Fiber Length [km]
• Possible to transmit signal up to 100 km fiber without using any
dispersion compensating elements
21
NOC group - AIT
www.ait.edu.gr
SOFI
All-optical nonlinear material
properties of SOH
All-optical processing possible
•
•
•
•
Nonlinear coefficient
22
NOC group - AIT
Due to third-Order Nonlinear Interaction of signals with nearly
identical carrier frequencies
Nonlinear coefficient is very large in SOH [ n2= 1.7 ± 0.8 x 10 -17
m2/W
Very high TPA figure of merit > 2 in slot-SOH type structure
Large birefringence > 3
 Self Phase Modulation (SPM), Cross Phase Modulation (XPM) ,
Four-Wave-Mixing (FWM), Cross Polarization Phase Modulation
(XPolPM)
www.ait.edu.gr
SOFI
Possible application and specification of
SOH as all-Optical processor
All-optical signal processing element operating beyond 100 Gbit/s
•
•
•
•
Wavelength conversion [FWM, XPM and Nonlinear Polarization rotation)
Modulation format conversion
XOR, flip-flop, and other logic gate operation
Optical time-division demultiplexing
Transmission/ absorption recovery time
Conversion efficiency @ Switching
energy
Intrinsic loss
Birefringence
Operating wavelength range
Wavelength dependency of conversion
efficiency difference
Data rates
Spectral efficiency
OSNR penalty
Feasibility and status of the SOH
performance
23
NOC group - AIT
FWM
XPM
XpolPM
< 1 ps
-18 dB @
< 1 ps
-18 dB @
< 1 ps
-18 dB @
3fJ
< 5 dB (<1.5dB/mm)
C/ C+L
< ±1 dB
3fJ
< 5 dB
C/ C+L
< ±1 dB
3fJ
< 5 dB
> 5 dB
C/ C+L
< ±1 dB
> 100 Gbit/s
Support multi-level
modulation formats
negative
Possible & demonstrated @
56 Gbit/s with high switching
energy; device optimization
is required
> 100 Gbit/s
Support multi-level modulation
formats
> 0 dB
Possible & demonstrated @
42.7 Gbit/s with high switching
energy , device optimization is
required
> 100 Gbit/s
Support multi-level
modulation formats
> 0 dB
Possible & need to be
experimentally
verified
www.ait.edu.gr
Comparison with other
Comb-generation Methods
SOFI
Clock freq
= 12.5 GHz
Bias-1
Clock freq
= 12.5 GHz
Clock freq
= 25 GHz
Clock freq
= 12.5 GHz
6 dB
6 dB
Bias-1
Bias-1
Dual Drive
MZM
Dual Drive
MZM
MZM
Clock freq
= 25 GHz
Bias-2
Bias-2
Bias-2
24
Dual-Drive MZM
Our method
Dual-drive MZM
Using diplexer [5]
RF clock frequency
Source required
Basic 
Second Harmonic X
Basic 
Second Harmonic X
Drive Aplitudes (Vpi)
@f0 => 0.96 
@2f0 => 0.94
@f0 => 1.0 
@2f0 => 0.97
@MZM(1) = 1.17 XXX
@MZM(2) = 2.47
Biases
@f0 => 0.5
@2f0 => 1.0
@f0 => 1.0 
@2f0 => 0.4
@MZM(1) = 1.0 
@MZM(2) = 0.35
Number of comb-lines
8 
7
7
Peak optical power in comb
-10 dBm X
-7 dBm 
-8.3 dBm 
Spectral flatness (Max – Min)
0.93 dB X
0.84 dB X
0.51 dB 
Extinction ratio (dB)
49.2 
49.5 
49.7 
Inventory
One DD-MZM 
Two RF clock source
RF Phase shifters
One DD-MZM 
Two RF clock source
RF Phase shifters
Diplexer
RF Power splitter
Two MZM X
One RF clock source
RF Phase shifters
RF Power splitters
High drive voltage
amplifiers
Complexity
Simple 
Moderate
Complex X
Cost
Cost effective 
Costly 
Relatively costly X
NOC group - AIT
MZM
Two MZM method [2]
Basic 
www.ait.edu.gr
SOFI
Initial Experimental Results:
with 10 GHz and 20 GHz RF Clocks
OSA Spectrum Version=4 ResBW=0.01, Sens=2, Pts=1202, Center=1549.59,
Span=3.00 Date='2010-10-08 15:12' Intensity (dBm/RBW)
OSA Spectrum Version=4
ResBW=0.01, Sens=2, Pts=1202,
Center=1549.59, Span=3.00
Date='2010-10-08 15:12' Intensity
(dBm/RBW)
-10
Electrical drive RF signals
-15
-20
optical Power (dBm)
-25
-30
-35
-40
-45
-50
-55
-60
-65
-70
-75
-80
1547.5
1548
1548.5
1549
1549.5
1550
1550.5
1551
1551.5
Wavelength (nm)
With combined RF signal of 10 GHz and 20 GHz
– 8 comb-lines with unequal power ~2.5 dB
– Drive amplitude was enough
– Distorted clock signal of 20 GHz due to clock divider response
– A better clock source would be required to achieve flatness < 1 dB
25
NOC group - AIT
www.ait.edu.gr