Post on 08-Apr-2018
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The Energy Efficient Photonics
Revolution
John BowersDirector, Institute for Energy Efficiency
Collaborators
UCSB: Dan Blumenthal, Larry Coldren, Martijn Heck, Jock Bovington, Molly Piels, Yongbo Tang,Daoxin Dai, Sid Jain, Jon PetersIntel : Richard Jones, Mike Morse, Yimin Kang, Mario Paniccia, Brian KochAurrion: Eric Hall, Alex Fang, Greg FishHewlett Packard: Di Liang, Marco Fiorentino, Raymond G. Beausoleil
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Focused Solutions - Research
Lighting
A $1 LED light bulb 20x more efficient than an incandescent bulbElectronics and Photonics
Wireless and optical technologies for super-high-performance communicationsComputing A new Moores Law for more energy-efficient computing
Buildings and Design
Economically viable zero net-energy building systemsProduction and Storage
Solar cells with double efficiency at one-tenth the costEconomics and Policy
Worldwide energy efficiency policy direction, measurements and standards
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Institute of Energy Efficiency
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Global Data TimelineSlide Courtesy Intel
2007 2008 2009 2010 2011
1ZB
500EB
1.5ZB
2ZB
Generated dataexceeds global
storagecapacity
A Zetabyte of
data isgenerated in
one year
Twice as muchdata generated
than can bestored
126 million blogs234 million websites
1.73 billion web users
90 trillion emails sent
A Flood of Data is being created at a60% growth rate may become more than we can handle!
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That Date Needs to be Accessed:IP Traffic Growth
Inte
rnettraffic(exabit/ps1MillionT
bps)
5
Internet video to pc
File sharing
Source: Cisco VNI June, 2009
Cisco forecast
Minnesota
Traffic Study
2 dB/year
Internet traffic
R. W. Tkach, Bell Labs Tech. J., 2009.
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Transmission Research records
1986 1990 1994 1998 2002 200610
100
1
10
100
Capac
ity
on
a
singlef
iber
Gb/s
Tb
/s
2010
Plot courtesy of P. Winzer and Chris Doerr
WDM started PDM started
Space Division Multiplexing(SDM) startingPhase diversity
started
1980: 50 Mbit/s
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How do we get to Terabit Optical Ethernet?
100G standards being commercialized 200G and 400G are
next then onto Terabit
Complex, highly integrated
circuits are needed
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100 Gb/s Transmit
100 Gb/s Receive
Value of Photonic Integration: Size,Weight and Power Reduction
100 Gb/sReceive
100 Gb/sTransmit
R. Nagarajan, Infinera ECOC 2007
InfineraSolution
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Photonic Integration for Coherent Optics(PICO)
Create a new generation of photonic integration engines that provideunprecedented and practical control of optical frequency and phase, driving alevel of sophistication that is routine today for RF into the optical domain.
Goal:
2009 2010 2011 2012 2013 2014
Capability
1Tb/s Integrated
Tx/Rx Capacity
100Gb/s All-Optical
Coherent Regeneration
256 QAM
Coherent PICs
Ultra-Narrow andTunable InP/Si Lasers
& Laser Arrays
Epitaxial InP on Si
PICs
THz-Bandwidth ChirpedLidar & mmW Sources
QPSK Coherent
PICs
100Gb/s IntegratedTx/Rx Capacity
1st Gen Optical
Phase-Locked Loops
1st Gen Hybrid InP/Si
Laser Technology
350 GHz fmax HBT
OPLL ASICs
2009 2010 2011 2012 2013 2014
Capability
1Tb/s Integrated
Tx/Rx Capacity
100Gb/s All-Optical
Coherent Regeneration
256 QAM
Coherent PICs
Ultra-Narrow andTunable InP/Si Lasers
& Laser Arrays
Epitaxial InP on Si
PICs
THz-Bandwidth ChirpedLidar & mmW Sources
QPSK Coherent
PICs
100Gb/s IntegratedTx/Rx Capacity
1st Gen Optical
Phase-Locked Loops
1st Gen Hybrid InP/Si
Laser Technology
350 GHz fmax HBT
OPLL ASICs
Coldren, Bowers, Rodwell, Johansson (UCSB),
Yariv (Caltech), Koch (Lehigh), Campbell (UVA), Ram (MIT)
LIDAREthernet Rx
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Terabit Optical Ethernet CenterBlumenthal, Bowers, Coldren, Rodwell
Mission Statement: To lead the way in a new roadmap for multi Tbps Optical Ethernet Create new energy efficient photonic integrated technologies
1020202015
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Monolithic Integration
UCSBMOTOR
Switch + diagnostic elements
Switch elements
PLSI
S. C. Nicholes, et al.
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Why Silicon Photonics?
Utilize advanced fabrication technologies for low cost, high volume integrated photonics.
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The Solution: Optical Interconnects
3D layer stacking will beprevalent in the 22nmtimeframe
Intra-chip optics can takeadvantage of thistechnology
Photonics layer (withsupporting electricalcircuits) more easilyintegrated with high
performance logic andmemory layers
Layers can be separatelyoptimized for performanceand yield
Opti
ca
lI/O
Logic Plane
O
ff-c
hip
opti
ca
l
sig
na
ls
On
-chip
optic
altr
affic
Photonic PlaneMemory Plane
Kash, Photonics in Supercomputing:
the Road to Exascale, IPNRA, 2009
BUT: Silicon has an indirect gap and doesnt emit light!So, how to integrate sources?
BUT: Silicon has an indirect gap and is a poor absorber (not1.55 m)! So, what about photodetectors?
BUT: Silicon is centrosymmetric (not electro-optic)!So, how to integrate modulators?
BUT: SiO2 is thermally resistive. So, power dissipation ofactive devices is a problem, particularly for rings and DWDM
BUT: Silicon is reciprocal. How to make an isolator?
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Hybrid Silicon Photonics
Silicon rib waveguide onSOI wafer
III-V active region
Optical gain from III-V Material Efficient coupling to silicon passive photonic devices No bonding alignment necessary: suitable for high volume CMOS All back end processing low temperature (
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Silicon Evanescent DFB Lasers
16
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Arrays of 16 DFBs with ElectroabsorptionModulators and Photodetectors
17
Laser Abandgap
Laser Bbandgap
16 DFB/PDlaser array
8 IntegratedPD-DFB-EAM
EAMbandgap
EAMbandgap
ISLC 2010, Kyoto , JapanWA3 9.15 - 9.30 Integrated Broadband Hybrid Silicon DFB Laser Array using Quantum Well Intermixing
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Hybrid Silicon Microring Laser: Path to lowthreshold and low power
III-V
Si
D. Liang, et al. Optics Express , 17 ( 22 ), 20355-20364 , October 23 , 2009
0.4 pJ/bit10 mA, 1 V =10 mW25 Gbit/s
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TW-EAM Structure
Small Footprint: 240 x 430mLarge bandwidth: 42 GHz
430m
240
m
-6
-5
-4
-3
-2
-1
0
1
0 10 20 30 40 50
E/Ore
sponse[dB]
Frequency [GHz]
42GHz
Bitrate:50 Gb/sER: 9.8 dBVpp: 2 V 20ps
Tang et al. OFC 2011
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20
Rattner, IPR Plenary,
Postdeadline (2010)
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21Rattner, IPR 2010
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Next Generation Optical USB
Every computer, SAN, Display,Rattner, IPR 2010
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Maximum configuration for CRS-1 92 Tbps (80 racks)
~1 Megawatt!!!
Problem: Bandwidth demands scaling faster than both silicon andcooling technologies
State-of-the Art Electronic IP Router
*Courtesy of Steve Nicholes
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D. J. Blumenthal,
Director, LASOR25
UCSB LASOR:a Label Switched Optical Router
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International Symposium on Ultra-high Capacity Optical Communication and Related OpticalSignal Processing and Devices Technical University of Denmark, Lyngby, Sept. 16 17, 2010
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LASOR PIC Technologies
An 8x8 InP Monolithic Tunable Optical Router (MOTOR) Packet ForwardingChip, S. C. Nicholes, et. al., IEEE JLT, Special Issue on OFC, (2009)
(Invited).
M. J. R. Heck et al., "Integrated Recirculating OpticalBuffers," in SPIE Photonics West 2010, Proc., CA, 2010.
Optical BuffersMOTOR
Packet Forwarding Chip
CAM All-Photonic Wavelength Converter
Tauke-Pedretti, A., et. al., "Separate Absorption and Modulation Mach-Zehnder Wavelength Converter," Lightwave Technology, Journal of , vol.26,
no.1, pp.91-98, Jan.1, 2008
Vikrant Lal, et. al., "Monolithic Wavelength Converters for High-SpeedPacket-Switched Optical Networks," Selected Topics in Quantum Electronics,
IEEE Journal of , vol.13, no.1, pp.49-57, Jan.-feb. 2007
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Si3N4 waveguides on Si platform
iPhoD at UCSB (Blumenthal, Bowers)
iPhod = Fiber Like Losses on Chip -> 10x, 100x, 1000x reduction over todays losses
20 meter spiral delay line
3 cm
Q of >10 million. 30 MHz linewidth
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Data Centers:
Higher Capacity switchingSmaller size, weight and power
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Network Interface Rate
*Courtesy of R. W. Tkach,OIDA Annual Forum 2009
100 Gbit/s Interfacesare available.
100 Gbit/s switchingdoes not exist yet.
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Eliminating the OEO conversion and eliminating theelectronic switch reduces power and scales to highercapacity.
Power dominated by optical amplifiers (to make up forloss) and FPGA controller
Power Savings
1.E04
1.E03
1.E02
1.E01
1.E+00
1.E+01
1.E+02
1.E+03
FastOptical
Switch
Fast
Electrical
Switch
Ethernet
Switch
CoreRouter P ONONU IPTVServer
Energy
perbit(nJ)
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Port speeds increasing rapidly 1Tb/s coming in near term Fabric radix increasing
Fibers connecting more nodes
Trends in Switching and HPC
At 1Tb/s line speed and 100s of nodes, 100Tb/ssystem needed
Fibers connecting boards.Moving to fibers connecting chips...Switching is critical...
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0 5 10 15 20
-18
-12
-6
0
6
12
18
3 m @ 20oC
4.4
3.01.75
1.0
0.7
Frequency
response
(dB)
Frequency (GHz)
0.35 35 Gb/s
semi-insulating GaAs substrateAR coating
injector
pad
oxide
aperture
BCBgate contact
channel contact
active
region
gate pad
channel
pad
SiN sidewall
i-DBR
p-DBR
n-DBR
semi-insulating GaAs substrateAR coating
injector
pad
oxide
aperture
BCBgate contact
channel contact
active
region
gate pad
channel
pad
SiN sidewall
i-DBR
p-DBR
n-DBR
Novel Vertical-Cavity Surface-Emitting Lasers (VCSELs)
Coldren
State-of-the-Art diode VCSEL 25 and 35 Gbit/s Field-Induced Charge-
Separation Laser50 and 100 Gbit/s?
0 1 2 3 40
1
2
3
4
5
0 1 2 3 40
0. 2
0. 4
0. 6
0. 8
1
0V
-1 V
-2 V
-3 V
-4 V
Bias current, Ibias (mA)
Diodevoltage,Vpn
(V)
Lightou
tput(mW)
Vgate
DC and RFmeasurement
Channel
Injector
GateIbias
VpnVgate
FICSL
0 5 10 1 5-20
-15
-10
-5
0
5
10
15
20
Frequency(GHz)
Response(
dB)
Ibias = 4 mA
f 3dB ~ 11 G Hz
V gate = 0V
5 m @ 20C
~ 11GHz
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s.j.wallach.super2000.11.200033
PetaFlop System
I/O
ALL-OPTICALSWITCH
Multi-DieMulti-Processor
1
2 3
64
63
49
48
4 5
16
17
18
32
3347
46
128 die/box4 CPU/die
10 meters= 50 NS Delay
...
...
...
...
LAN/WAN
High Performance Computing Scaling
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Power Consumption
Co
mputationalThrough
put
1 kW10 kW100 kW1 MW10 MW
Peta-FLOPS in
a rack
HPC performance spaceexpanded by Chip-to-Chip
Optical Interconnects
electrical inter-chipinterconnect barrier
overcome by OI
OI at ~100 fJ/bit*
*D. A. B. Miller, IEEE Proc., 2009
High Performance Computing Scalingenabled by Optical Interconnects
100GFLOPS
1TFLOPS
10TFLOPS
100TFLOPS
1 Peta-FLOPS
10 Peta-FLOPS
OI at ~1 pJ/bit
100 x lower power!
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Summary
Photonics provides lower power, more efficient waysto communicateon a wide area, local area, andwithin data centers and supercomputers.
Integration is essential for size, weight, power andcost reduction and improved yield and reliability
Hybrid silicon photonics can integrate thistechnology with CMOS.
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