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TRANSCRIPT
Atul Srivastava
CTO, NTT Electronics - America
Low Power DSP and Photonic Integration in
Optical Networks
Market Focus ECOC 2014
NTT Electronics Corp. ©2013 – proprietary & confidential
Outline
• 100G Deployment
– Rapid Growth in Long Haul
– Role of Modules
• New Low Power 100G DSP
– Based on 20nm CMOS
– Versatile: Many Applications
– Pluggable Modules (CFP, CFP2…)
• Integration in Optical Components
– InP Devices
– Si Photonics
– Compact Tx/Rx with DSP assist
• Discussion
2
NTT Electronics Corp. ©2013 – proprietary & confidential
100G Deployment Trends
3 Exponential Growth: Doubling 1.5-2 years
NTT Electronics Corp. ©2013 – proprietary & confidential
100G Coherent Metro Networks
4
Metro Regional
Metro Core
Long-Haul
Metro Access
• Long-Haul >1500, 6-8 ROADMs
• Metro-Regional
500-1000km; 16 ROADMs
• Metro-Core 100-500km; 24 ROADMs
• Metro-Access
40-100km
Typical Optical Specs: 16dB OSNR, 15,000ps/nm dispersion, 12ps PMD
Cost, Power and Size of module are key metrics for 100G Metro
NTT Electronics Corp. ©2013 – proprietary & confidential
100G Modules and Line cards: Lower Power and
Smaller Size Enabling higher card density
2012
100W
Size (Smaller)
Power Consumption
5
2016
45W
OIF Gen 1 5x7 MSA 80W
OIF Gen 2 4x5 MSA 45W
CFP <30W CFP2 ACO 12W
2014
Module Power
dominated by
electronic
components
Lower Power DSP
Module Size determined by
optical
components
Tx & Rx
More Integration
NTT Electronics Corp. ©2013 – proprietary & confidential 6
100G Transceiver Module/DSP Power Dissipation
5”x7”
4”x5”
CFP 40nm CMOS
28nm
20nm
NTT Electronics Corp. ©2013 – proprietary & confidential
Gen-2 Gen-1
Trends on Coherent Transceiver MSAs
7
Multi-haul, Telecom
Non-LH Telecom/Datacom
5’’x7’’
CFP
DSP
Rx
Mo
d.
Mo
d. DSP
Rx
Mo
d.
DSP
Rx
4’’x5’’
DSP
CFP2
ACO
2011 2013 2015~2017
OIF Gen-2 IA
Editor: Atul Srivastava
Long-haul, telecom
NEL
DSPs
NTT Electronics Corp. ©2013 – proprietary & confidential
NTT Electronics Corp. ©2013 – proprietary & confidential
NLD0629 100G DSP
• 40-nm CMOS
• External transmit MUX, external framer ASIC
9
100G
Optical
Front-End
SD-FEC
encoder
SD-FEC
Decoder
(FEC)
Fixed
Equalizer
(FEQ)
Adaptive
Equalizer
(AEQ)
4ch
A/D
converter
I/O
IF
I/O
IF
Other
Rx
DSP
TX
DSP
I/O
IF
MUX
IC
Dual
I-Q
Mod.
XI
XQ
YI
YQ
XI
XQ
YI
YQ
Framer
IC
NTT Electronics Corp. ©2013 – proprietary & confidential
NLD0640 100G LP-DSP
• 20-nm CMOS • Internal 4x DAC, internal framer with EFEC • 70%-less power consumptions and footprint
– If compared with 40-nm three-chip solution
10
100G
Optical
Front-End
SD-FEC
Encoder
SD-FEC
Decoder
(FEC)
Fixed
Equalizer
(FEQ)
Adaptive
Equalizer
(AEQ)
4ch
A/D
converter
I/O
IF
I/O
IF
Other
RX
DSP
Line estimation
TX
DSP
4ch
D/A
converter
Dual
I-Q
Mod.
XI
XQ
YI
YQ
XI
XQ
YI
YQ
Fra
me
r
Lower Power <20W with 20nm
NTT Electronics Corp. ©2013 – proprietary & confidential
Target Applications
11
Long Haul (LH)
~ 2,000 km
p2p DWDM
Metro-Regional (MR)
~ 600 km
ROADM Ring
Metro-Access (MA)
~ 600 km
p2p WDM
ZR
~ 100 km
Dark Fiber
Data Center
Data Center
Gen
-1 D
SP
Gen
-2 L
ow
Po
wer
DS
P
2012 ~
2013 ~
2014 ~
2014 ~
NTT Electronics Corp. ©2013 – proprietary & confidential
Specifications selectable function matrix
12
SD-FEC
(LDPC)
7%
HD-FEC
CD compensation
(ps/nm)
OFF
55,000
20,000
10,000
2,000
Nyquist
filter
ON
OFF
Client
100GbE
OTU4
ON
OFFG-FEC
E-FEC
Items SpecificationModulation format DP-QPSK
Nyquist filter ON / OFFSignal bit-rate(Selectable)
127.2 Gb/s (OTU4V mode)111.8 Gb/s (OTU4 mode)
Chromatic dispersion compensation +/-55,000 ps/nmNet coding gain 11 dB (SD-FEC + E-FEC)
Dispersion estimation time 17 msecPolarization tracking speed 50 KHz
Frequency offset compensation +/- 5 GHzClient signal (Selectable) 100GbE CAUI / OTU4 OTL4.10
100GE
G-FEC OFF
2,000
OFF
Short range (100 km)
E-FEC ON
20,000 OUT4 OFF
Metro access (1,000 Km)
NTT Electronics Corp. ©2013 – proprietary & confidential
Lower Power by 20nm and function selection
13
Lower Power < 20W with 20nm
NTT Electronics Corp. ©2013 – proprietary & confidential
Current Solutions for Coherent MSA
14
• 40nm discrete three-chip configuration
– 100G OTN Framer,
– 100G DSP, and
– Transmit Mux
NTT Electronics Corp. ©2013 – proprietary & confidential
Coherent CFP enabled by LP-DSP
• LP-DSP integrated the three-chip functions
– 70%-less power dissipations
– 70%-less foot print
• If compared with three-chip solutions
15
NTT Electronics Corp. ©2013 – proprietary & confidential
LP-DSP mounted CFP with InP Modulator
16
THPDP1-4:OECC2014 PDP
SD-
FEC
Modulator
Controller MDIOinterface
TX Output(Optical)
IntegratedReceiver
10
10
10 Gbps x 10
Rx Input(Optical)
OTU4/100GE
DAC
ADC
ModulatorDrivers
Coherent
DSP
Tu
nab
le
Laser
Fra
mer
InP DP-IQ
MDIO: Management Data Input/Output
Photo courtesy of
NTT Electronics Corp. ©2013 – proprietary & confidential
InP-based DP-IQ modulator
17
-30
-25
-20
-15
-10
-5
0
-4 -2 0 2 4
XI XQ YI YQ
Push-pull driving voltage [V] N
orm
. ou
tpu
t p
ow
er [
dB
]
p/2
p/2
In
XI
XQ
YI
YQ
PMF
SMF
Out
• Differential drive
• SMT I/F for RF
• FPC I/F for DC
• Bias voltage: < 10 V
• Vp: 1.9 V@DC, < 2.5 V @ 32 GBaud
• Module size: 12×39 x 6.5 mm
Modulator configuration InP DP-IQ modulator
(12 x 39 x 6.5 mm)
Extinction characteristics
NTT Electronics Corp. ©2013 – proprietary & confidential
Tunable laser: micro ITLA
18
Micro-iTLA (20 x 35 x 6.9 mm)
Compact tunable laser module (8 x 15.25 x 6.2 mm)
Fiber
Wavelength Locker Tunable DFB Laser Array
PD2
TEC1
Etalon Filter
PD1
TEC2
• Compact laser module installed in OIF
compliant micro-iTLA
• Use of stable DFB array-type LD
• Output power: 16 dBm
• Spectral linewidth: < 300 kHz
Spectral linewidth @ ITU-T Grid
PETRA Confidential
NTT Electronics Corp. ©2013 – proprietary & confidential
ICR (Integrated coherent receiver)
19
• OIF compliant (type 2)
• Silica-based PLC DPOH (Dual
Polarization Optical Hybrid)
• Hybrid integration of photodiodes via
micro lens array
• Wide input power dynamic range with
integrated VOA
Module configuration
Waveguides
4-ch PD array
Micro-lens array
Silica PLC
Side view
Signal line
TIA
Base
Integrated coherent receiver (16 x 30 x 5 mm)
PETRA Confidential
Subcarrier
NTT Electronics Corp. ©2013 – proprietary & confidential
Coherent detection with ICR
20
LO power = 13 dBm OSNR = 16 dB
PETRA Confidential
NTT Electronics Corp. ©2013 – proprietary & confidential
Eye-diagram and consternation
21
X Pol.
Y Pol.
X Pol.
Y Pol.
OSNR: 30dB (0.1nm resolution)
Real-time received constellations Transmitted optical waveform
NTT Electronics Corp. ©2013 – proprietary & confidential
Real-time measured post-FEC BER vs. OSNR
22
NTT Electronics Corp. ©2013 – proprietary & confidential
Si photonics
• Leverage CMOS facilities
Ecosystem including ext. CMOS fab is to be established.
Good mass producibility: wafer size is 8 or 12 inches
• Shrink size of optical devices
Smaller optical circuits (R~5mm)
Larger propagation loss, phase error,
– and polarization dependence must be handled
Coupling with optical fiber is challenging
• Can integrate active elements such as modulator and photodiode
delta = 41.32%, 0.33166x0.33166
-10 -5 0 5 10-10
-5
0
5
10
delta = 0.3%, 7.2x7.2
-10 -5 0 5 10-10
-5
0
5
10
SM fiber Si nanowire
SiP InP Silica PLC
Passive Yes Yes Yes
PBS, PR Yes Difficult Yes
Modulator Yes Yes Hybrid
PD Yes Yes Hybrid
Laser Hybrid Yes Hybrid
TO effect ~10-4 /T ~10-4 /T ~10-5 /T
NTT Electronics Corp. ©2013 – proprietary & confidential
Electronics integration with Si photonics
Photonics: WDM filter array and Ge PD array Electronics: TIA integration by flip-chip bonding
100G one-chip Rx
25 G x 4-ch TIAs
4l x 25G TIA output of 25 G IMDD (PRBS 231-1) PD input: -10 dBm K. Takeda, GFP’14
HF evaluation set-up
HF probe HF probe CPW
CPW chip
PIC wafer
NTT Electronics Corp. ©2013 – proprietary & confidential
Compact Optical Tx and Rx …DSP Assist
DSP
PBC
AD
C
DAC PBS
LD
LD
Tx
Rx
Coupling
loss
Chirp
Phase error
Extinction
ratio
Loss
imbalance
Vpi
Coupling
loss
Coupling
loss
Performance enhancement by DSP
NTT Electronics Corp. ©2013 – proprietary & confidential
26
Thank you