Silicon Photonics for HPC Interconnects, 100 Gbps and Beyond

1 Luxtera Company Overview

• Founded: 2001 • Pioneered a new class of ¾ Spin Out from Caltech Semiconductor “Silicon CMOS • Headquarters Photonics”Photonics ¾ Carlsbad, CA ¾ Enables Single CMOS chip opto- • Privately Held electronic transceiver ¾ Shipping product for revenue ¾ Breaks both performance and price/performance barriers • Strong Intellectual Property Portfolio ¾ Over 80 US Patents issued ¾ Over 40 additional pending

Brian Welch, [email protected] 2 Overview

• Motivations – IBTA Interconnect Roadmap • Silicon Photonics – Technology Summary • Contemporary Applications – 40 Gbps QSFP Active Optical Cables • Next Generation Solutions – 25 Gbps per lane interconnects • Beyond 25 Gbps

Brian Welch, [email protected] 3 Motivations

• Enterprise interconnect throughput has increased by over 10x in the last dddecade – From 10Gbps per link to 120 Gbps • Within two years solutions capable of over 300 Gbps will be required – Next generation enterprise CPUs can deliver up to 320 Gbps of signaling • Ability to scale out is limited, driving the need for InfiniBand IBTA Roadmap Plans for 100G drama tillhihtically higher ser ilial EDR need for 2011 rates – Over 25 Gbps per Lane

Brian Welch, [email protected] 4 Silicon Photonics TECHNOLOGY SUMMARY

Brian Welch, [email protected] 5 Silicon Photonics

• Silicon Photonics is a scalable platform capable of meeting the increasing needs of the enterprise world.

– Silicon Photonics has near infinite optical bandwidth.

• Silicon Phot oni cs scal es with the ITRS roa dmap, ensuring interconnects will not be the limiting factor in fabric development.

– Silicon Photonics scaling is cost neutral.

Brian Welch, [email protected] 6 Silicon Photonics

EPIC –Electro Photonic Integrated Circuit

Fully Integrated CMOS Silicon Photonic Circuits Standard CMOS Analog & Digital Circuits Photonic, Analog & Digital Circuits

Silicon Photonics

Waveguides Waveguide Structures + =

Vertical Couplers High/Low Speed Modulators

Added to standard Silicon Enables: Low‐cost, high Waveguide Photo‐detectors Integrated PD & TIA/LA CMOS chip fab and CMOS chip volume optics platform

Luxtera’s CMOS Photonics technology design flow

Brian Welch, [email protected] 7 Photonics and Electronics on a Common Wafer

Based on Commercial Process : • “Photonically-enabled” CMOS process • “Pluggable” p rocess modules added for p hotonics • All processes and tools used are standard and fully compatible with CMOS

Based on Commercial Process : Metal 1 “Photonically-enabled”Poly Gate Salicide CMOS Block process Contacts “Pluggable” process modules added for photonics Ge All processes a nd too l s usedField ar e Oxide stan dar d an d f ull y compatible with CMOS Active Si

Buried Oxide

Si Substrate

Brian Welch, [email protected] 8 Silicon Photonics Key Components

25G MZ Modulators 25G Integrated Photodiodes

Vertical Optical Coupling Wafer‐Scale Testing

Brian Welch, [email protected] 9 Low Cost Light Sources for CMOS Photonics

• Integration of light sources with • For multi‐channel transceivers a CMOS photonics: single laser can be shared between • CW Laser always on – Like a DC the channels reducing laser cost power supply • Since the laser is always on, no need for expensive high‐speed Lasers

Micro‐packaged laser: Flip‐chip laser: Light Source

Passive Splitters 8 MZI Optical Modulators Interfaces

Brian Welch, [email protected] 10 Contemporary Applications 40 GBPS QSFP AOC

Brian Welch, [email protected] 11 Blazar 40 Gbps QSFP AOC

Lowest Power: 780 mW typical; 1.09 W Max Longest Reach: Up to 4,000 meters Single Mode Fiber Lowest Bit Error Rate: <10-15 Bit-Error Rate QQggSFP Pluggable Lowest Latency: Active Cable Assembly 340ps per TX, 340ps per RX 5ns per meter of fiber High Bandwidth: 24 AWG Passive Copper <7m 42 Gbps (4 x 10 .52 Gbps)

32 AWG Standards Compliant: Active Copper Fiber QSFP MSA mechanical compliance <12m 4,000m Ethernet SFP+ compliant electrical interface IBTA QDR compliant (UNH Certified) High Reliability: MTBF > 5 Million hours FIT < 200

12 Blazar 4x10 Gbps Silicon Photonics IC

Unprecedented Opto/Electronic CMOS Integration Optics • Fiber coupled directly to the die • Integrated wave guides 4x10 Gb/s • Integrated modulators Electrical • Integrated photo‐detectors SFP+ Analog and Digital Electronics Digital Receivers • Integrated modulator driver Core

• Integrated amplifiers • Integrated digital functions Transmitters OtilOptical Applications 4x10 Gb/s Interfaces Electrical • QDR 40G InfiniBand SFP+ • 4x10G and 40G Ethernet • PCIe Extensions • 4x8G Fibre Channel Monolithically integrated in mainstream SOI CMOS

Brian Welch, [email protected] 13 Blazar MSA Compliant Packaging

Brian Welch, [email protected] 14 Next Generation Solutions 25 GBPS PER LANE INTERCONNECTS

Brian Welch, [email protected] 15 Challenges of Scaling in Conventional Technologies

• Copper Interconnects: – Increasing lane rates drives the need for heavier gauge wiring, and/or shorter lengths – Increasing lane count increases fiber bulk and decreases usability • Multi-Mode Interconnects: – Increasing lane rate puts pressure on high speed VCSELs, mandating higher current densities – Fiber core and photodiode spot sizes need to reduce to enable rate scaling

Brian Welch, [email protected] 16 Advantages of Silicon Photonics

• Silicon Photonics only requires electrical scaling with increased data rate. – Silicon Photonics optical components have OE bandwidth far beyond any near term needs (over 100 GHz) – Silicon Photonics interfaces and medium remain constant irrespective of rate • Single mode fiber and waveguide type photodiodes – Silicon Photonics light sources are unmodulated, and require no modification to support higher rates

Brian Welch, [email protected] 17 Silicon Photonics at 25 Gbps

Luxtera’s Silicon Photonics is Demonstrated 25G EDR InfiniBand Ready Now! Performance • Clean Transmitter and Receiver Eye a long w ith Low Jitter Resu lts in: – Low Bit Error Rate – Long Reach

• No need for faster lasers – Current CW lasers can be reused

• Single Mode fiber is future proof – Over 2 Terabyte capable

•No significant incremental cost over 40G – Same Die size – Same Laser – Same Fiber

Brian Welch, [email protected] 18 Beyond 25 Gbps INFINIBAND HDR AND OTHER ADVANCED FABRICS

Brian Welch, [email protected] 19 Beyond 25 Gbps

• HDR tentatively scheduled for 2014 availabilit y • HDR likely to push signaling rates beyond 40 Gbps – Over 400 Gbps aggregate interconnect throughput • Terabit cables needed within the coming InfiniBand IBTA Roadmap Plans for 100G EDR need for 2011 decade?

Brian Welch, [email protected] 20