Gregory Fish, Aurrion Inc. USA OSA Optical Interconnects for Extreme-Scale Computing Incubator August 9-11, 2015 Heterogeneous Photonic Integration for WDM based Optical Interconnects
Gregory Fish, Aurrion Inc. USAOSA Optical Interconnects for Extreme-Scale Computing IncubatorAugust 9-11, 2015
Heterogeneous Photonic Integration for WDM based Optical Interconnects
Evolution of PhotonicsUsing the silicon manufacturing supply chain to make photonics
OSA Optical Interconnects for Extreme-Scale Computing Incubator, August 9-11, 2015
Conventional Silicon Photonics
In House Fabrication Foundry Infrastructure
Custom Packaging Techniques – Cooling, Gold Box Hermetic Packaging
OSAT Packaging - Self Hermetic, Uncooled
$$$$ $
Physics Based Simulations Silicon Based EDA
Transmission Line and decoupled drivers (cm) Electronic Co-design (<mm)
~10 pJ/bit ~pJ/bit
Heterogeneous Integration: Materials and Silicon Technologies
Heterogeneous Integration for Si photonic PICs: Combining multiple materials into a photonic circuit to use the best material for the function, while remaining compatible with Si foundry tools and processes.
Heterogeneous Electronic/Photonic Integration: Combining multiple Silicon technologies, including photonics together into a chip-scale microsystem.
OSA Optical Interconnects for Extreme-Scale Computing Incubator, August 9-11, 2015
Photonics
Heterogeneous Photonic Systems on Chip (SoC) Heterogeneous Electronic/Photonic System in Package (SiP)
NonlinearMaterials
DetectorsModulators &
Switches
Lasers
Low Loss Waveguides
Chip Produced in Silicon Foundry
MEMS
ITRS 2010Whitepaper
Hom
ogenous Integration
Heterogeneous Integration
4 fibers8 fibers
16 fibers
Scaling Bandwidth
OSA Optical Interconnects for Extreme-Scale Computing Incubator, August 9-11, 2015
25G
50G
100G
4 wavelengths8 wavelengths
16 wavelengths
Drivers for WDM in the Emerging Data Centers• Scale of largest Data Centers is driving
>500m interconnect lengths which requires Single Mode Fiber.
• IEEE Standards for SMF use WDM for reaches beyond 500m.
• 40G LR4 (10 km)• 100G LR4 (10km)• 400G FR8 (2km) & 400G LR8 (10km) (approved)
• Industry Standard based solutions need to be cost effective to avoid fragmentation.
1295 1300 1305 1310
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wavelength (nm)
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ower
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NRZ
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1295 1300 1305 1310
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1270 1275 1280 1285 1295 1300 1305 1310
wavelength (nm)
3
2
1
0
PAM4
OSA Optical Interconnects for Extreme-Scale Computing Incubator, August 9-11, 2015
Enabling Uncooled WDM
OSA Optical Interconnects for Extreme-Scale Computing Incubator, August 9-11, 2015
Close integration of electronics and photonics
Lasers operating over a wide temperature range
[B. Koch et al., OFC 2013, PDP5C.8]
[B. Lee et al., OFC 2015, Tu3.G3]
Modulators operating over a wide wavelength range
Electronics-like packaging
Heterogeneous Components and Processing for Uncooled WDM
OSA Optical Interconnects for Extreme-Scale Computing Incubator, August 9-11, 2015
Active materials
defined by lithography
No critical alignment
Mature silicon photonics passives
Integration of multiple III-V
Materials
Reduced topology for
Standard Processing
Hermetic at Chip Scale
Wafer scale processing
Die PlacementSubstrate Removal
III-V ProcessingInterconnect
Heterogeneous Integration Process
Demonstration of an Heterogeneous Integration platform for Silicon Photonics
• Processed on Silicon wafers using Foundry Infrastructure.• Optimized III-V Materials for Active Components with Silicon Photonics.• Heterogeneous III-V Components on Silicon Match and even Exceed performance of Native III-V substrate.
Heterogeneous Integration:Platform and Component Library Overview
OSA Optical Interconnects for Extreme-Scale Computing Incubator, August 9-11, 2015
Laser and SOAs
Modulators
High Speed Photodiodes
Passives and MUX/DEMUX
0.80.9
11.11.21.31.41.5
0 500 1000 1500 2000 2500 3000
Ith/I
th0
Hours
Wavelength Stabilized
Heterogeneous Process is Reliable
High Temperature OperationUncooled Lasers on SiliconHeterogeneous O-Band Laser• Uncooled (no TEC)• > 40 dB side mode suppression• <400 kHz linewidth• RIN <-145 dB/√Hz• Laser diode efficiency: ~15% at T=80C• Reliability demonstrated:
• >4M laser accelerated aging device-hrsand counting
OSA Optical Interconnects for Extreme-Scale Computing Incubator, August 9-11, 2015
WDM Laser Arrays
High yield integrated laser breaks cost barrier• Large WDM arrays processed in parallel
Uncooled operation• Wavelength-locking across temperature
(20-80C) without a TEC• 200GHz (or 800GHz) grid
OSA Optical Interconnects for Extreme-Scale Computing Incubator, August 9-11, 2015
High Speed ModulatorsElectroabsorption Modulator (EAM)• >35GHz 3dB bandwidth• Vpp=1.0 V (>4dB ER), 2V (~9 dB ER)• Compact (<200um) , <3 dB IL• <0.5 pJ/bit at 32 Gb/s with CMOS driver
Mach-Zehnder Modulator (MZM)• 23 GHz, 3dB bandwidth • < 3 V for Pi phase shift• >15 dB ER• < 3 dB IL
OSA Optical Interconnects for Extreme-Scale Computing Incubator, August 9-11, 2015
25 Gb/s
28 Gb/s
30 Gb/s
32 Gb/s
35 Gb/s
>35GHz
See OFC2015 Paper Tu3G.3
High Speed Photodiodes
Heterogeneous Waveguide PD
• p-i-n photodiode with InGaAs absorber and Si waveguide layer
• 3dB bandwidth >35GHz
OSA Optical Interconnects for Extreme-Scale Computing Incubator, August 9-11, 2015
20 Gb/s
30 Gb/s
40 Gb/s
50 Gb/s
60 Gb/s
Low Loss Passives
• Low-loss (<1dB/cm) silicon waveguides and low-loss crossings.
• High yield complex MUX/DEMUX structures with 200mm fabrication tooling.
• Athermal operation for uncooled WDM.
OSA Optical Interconnects for Extreme-Scale Computing Incubator, August 9-11, 2015
MUX/DEMUX
IO Coupling
Heterogeneous Integrated Photonic Circuits and Packaging for Uncooled WDM
Heterogeneous Photonic Circuit Manufacturing• Silicon photonics PIC using foundries
• Assembly using silicon OSATs
• Complete BGA transceiver
• Low cost optical connector attach
OSA Optical Interconnects for Extreme-Scale Computing Incubator, August 9-11, 2015
ConclusionsWDM is effective and necessary approach for bandwidth scaling, yet brings challenges.
Heterogeneous Integration on Silicon Photonics addresses the challenges:• Cost effective integration of laser and other III-
V materials.
• Athermal and tunable optical elements for wavelength.
• Intimacy with electronics for control and signal integrity through advanced Si packaging.
OSA Optical Interconnects for Extreme-Scale Computing Incubator, August 9-11, 2015