Outline

• A Powers of Ten Look at Network Components• Opto-electronic Integration and the Network Processor• Overview of Materials• Constructing a Technology Roadmap• Technology Barriers for Integration

Rajeev J. Ram

Director, Communications Technology RoadmapHead, Physical Optics and Electronics

Electrical Engineering and Computer ScienceMassachusetts Institute of Technology

powersof10.com

Optical NetworkOptical Network

UUNET

WDM Ring Network ArchitectureWDM Ring Network Architecture

Metro WDM Ring

Rx Tx A B C DA - 1 2 3B 1 - 4 5C 2 4 - 6D 3 5 6 -

Interconnect table Logical mesh

6 transmitter wavelengths required for 4 nodes.

OADM Node configuration

Tx Tx Tx Rx Rx Rx

amplifiers amplifiers

Node A

Rx TxRx Tx

1,2,3,4,4,5,5,6,6 2,3,4,5,6,6 3,5,6

Rx:1,2,3,4,4,5,5,6,6 Rx:1,1,2,2,3,4,4,5,6

Rx Tx

Rx:1,2,2,3,3,4,5,6,6

Rx Tx

Rx:1,1,2,3,3,4,5,5,6

Node B Node C Node D

1,2,3 1,1,2,3,4,5 1,1,2,2,3,4,4,5,6

MetroCO/POP

CO/POP

CO/POP

CO/POP

CO/POP

CO/POPCO/POP

CO/POP

Access

ADM

ADMADM

ADM

Local Loop

CoreSan Francisco

Seattle

SubmarineNetwork

Boston

Chicago

Metro

Putting It All Together: OADM NodePutting It All Together: OADM Node

R-TpV

Transmit & Receive TranspondersClient IP,ATM,SDH/SONET,PDHTransmit & Receive TranspondersClient IP,ATM,SDH/SONET,PDH

Pre-ampEast

Pre-ampWest

WDM

Power ampWest

Power ampEast

ControlChannel

WDM

WDM

WDM

MUX

Traffic Traffic

... ...DEMUX

R-TpRtpRtp TpTpTp Tp

MUX

Gain block•EDFA•Pump lasers•Detectors•980/1550 MUX•Isolators•Gain equalizers

Multiplexers•AWG•Thermoelectrics•Attenuators

Transceivers•EA modulator

+DFB•Thermoelectrics•Isolators•Detectors•Laser Driver•Receiver Amps

Defined, basic functions, standardsDifferentiation: hardware

Flexible, complexDifferentiation: software

. . .

DMUX

CDR

AGC

. . .MUXDRIVER

FRAMERSAND

MAPPERS

LAYER 2

TZA

OO

PP

TT

II

CC

SS

NPU SWITCH

FABRIC

Digital CMOS IC’sDigital CMOS IC’s

Optics EOI (PMD) EOI (PHY) Protocol Processors Fabric

Network Processors

Analog andAnalog andMixed Signal IC’sMixed Signal IC’s

and Modulesand Modules

Electronics and Electronics and Photonics Photonics Rx/Rx/TxTx

Receiver:photodiodereceiver power monitortransimpedance amplifierclock data recoverydecision circuitelectrical DeMUX

Transmitter:16 input electrical channels at 622Mbps9.95328Gbps laserlaser control and monitoringsingle-mode optical fiber pigtail

4.0'' L x 3.5'' W x 0.53'' H

Intel

~10-30M gates~2Gbits of memory 256 MB of route table memory 256 MB of packet buffer memory for receive and transmit~100-200 Watts of power dissipation~2 square feet>$10k cost

Cisco

OC-192 Linecard:

Electronics and Electronics and Photonics Photonics Rx/Rx/TxTx

Semiconductor Laser PackageSemiconductor Laser Package

Silicon

Other

InP/GaAs

Laser .1 λλ-LockPIN

Laser Driver

PIN/APD

TIA

CDR

RECEIVER

TRANSMITTER

TRANSPONDER

ISO

LIMITINGAMPLIFIER

Microcontrollerpower conditioning

Network control

Mod

PM/CDCM

Mux

Demux

ModulatorDriver

TEC controller

EPROM

TEC

Intel

Materials & Components in TransceiverMaterials & Components in Transceiver

Planar Planar Lightwave Lightwave Module: Fiber-to-ChipModule: Fiber-to-Chip

Communications Technology Roadmap (CTR) Objective: To providetechnology development targets for the long-term evolution of planaropto-electronic integration in the optical communications industry.

ACTIVE DEVICESdiode laser

SOAsmodulators

photodetectorsTE cooler

ELECTRONICSCMOS memoryFlip-flops/MUX

Transimpedance ampsBias circuitry

PASSIVE DEVICESAWGsVOAs

Dispersion ElementIsolator/Circulator

Opto-Electronic Integrated Circuits (OEICS)

Improvements in CMOS speed are madelargely from progress in lithographicdimensions — making devices smaller inorder to switch faster

Evolution

OC-48 (1980’s)GaAs MESFET, Si BJT Si CMOS

OC-192 (2001)GaAs, SiGe 0.5 µm Si CMOS

OC-768InP 1µm, SiGe SiGe BiCMOS?

Mitsubishi 70 nm cobalt silicide gate (ft=114G, fm=135 G, 11 dB gain at 40 G)

The SEMATECH RoadmapFiber-optic analog IC

Materials OverviewMaterials OverviewSubstrate SizeSubstrate Size

193 nm

365 nm

365 nm

157 nm

193 nm

365 nm

157 nm

157 nm

StepperTechnology

Not available

(Freiberger ‘02)

8”GaAs

3x103 cm-2

(AXT VGF ‘02)

6”InP

4”InP

2-5x103 cm-2

(AXT)3”InP

3-7x103 cm-2

(Sumitomo)6”GaAs

3-5 7x103 cm-2

(Freiberger)4”GaAs

-12”Silicon

-8”Silicon

EP DefectDensitySizeMaterial

Drafting Effect

Drafting Effect means scaling isn’t just number ofdevices but also tool set, feature size, performance

1x4 WDM (silicon nitride Rings)

1515 1520 1525 1530 1535 1540 1545

Wavelength (nm)

Po

wer

-- s

am

e s

cale

(au

)

Port1

Port2

Port3

Port4

Thru

0

1

0

1

Thru-portKimerling, MITMaki, MIT LL

LambdaCrossing (OFC 2002)•Thermo-optic switched

microring•6 dB insertion loss•6” Si process•FSR of 80x50GHz

Advanced Lithography for Advanced Lithography for Ultracompact Ultracompact ComponentsComponents

s Laser: Single E / O device

s Detector: Single O / E device

s Modulation Driver: ~100 Transistors

s Transimpedance Amp+LA: ~ 50-100 Transistors

s Mux/DeMux: 1,000-10,000 Transistors

s Framers, and Mappers: 1,000,000 gates

Laser .1 SOA λλ-LockPIN

ModulatorDriver

Laser Driver

PIN/APD

TIA

DEMUX

CDR

MUX

RECEIVER

TRANSMITTER

TRANSPONDER

MODISO

LIMITINGAMPLIFIER

Framer

Framer

The Complexity Barrier

InP HBT – 3000 transistors

InP HEMT – 100 transistors (e-beam lith)

SiGe/Si – 10,000,000 transistors

Laser .1

λλ-Lock

PIN

Laser Driver

ISO

Mod

Mux

ModulatorDriver

TEC controller

PIN/APD

TIA

CDR

LIMITINGAMPLIFIER

Microcontroller

power conditioning

CDCM PMDCM

PM/CDCM

Demux

EPROM

Silicon Signal

Silicon Control InP/GaAs RF/Opto

Other opto materials Lithium niobate InP e-o/e-a/e-refr.

YIG thin film waveguides

Thin film filters waveguide lockers

Fiber Bragg gratings organics / photonic

crystals

Roadmap Fundamentals

Why Develop a Roadmap?

→ Reduce financial risk

→ Guide allocation of resources

→ Improved alignment of organizational decision making

"A 'roadmap' is an extended look at the future of a chosen field of inquirycomposed from the collective knowledge and imagination of the brightestdrivers of change in that field.“ -- Robert Galvin, former Chairman, Motorola

Key Elements of a Technology Roadmap:

→ Identify drivers, barriers, actions and a timeline for development

→ Developed by consensus

→ Not “forecasting” – but creating a vision for the future

→ Not a single snapshot in time Technology

Industry

Policy

CTR Project Overview

Assessment of Current Technologies - DWDM

Assessment of Current Technologies - DWDM

Industry Perspective of Optical Network Evolution

Industry Perspective of Optical Network Evolution

Technology EvolutionTechnology Evolution

Bottom-Up Analysis: Manufacturing Cost DriversBottom-Up Analysis: Manufacturing Cost Drivers

Sept 2002Jan 2002 Jan 2003 Sept 2003

CTR IndustryWorkshop at MIT

Microphotonics Industry Consort ium Conference Apr 2002

TWG: Photonic Integrat ion in III-V

T W G : Opto-Electronic Integration in Si l icon

TWG: Appl icat ions for Organics in O E I C s

Communicat ions TechnologyRoadmap Conference Nov 2002

Industry Interv iews – Process equipment ,components, equipment, carr iers , etc . . [21organizat ions, >55 interviews]

Database of funct ionalper formance metr icsFundamental mater ia lproperties

Process-Based CostAnalys is Model forIntegrated PhotonicCircuits

Microphotonics Industry Consort ium Conference May 2003

TWG: Hybr id Integrat ion

Assessment of Current Technologies – Optical Access

Assessment of Current Technologies – Optical Access

Roadmapping MethodologyRoadmapping Methodology

CTR Technology Working Groups (TWGs)

“Photonic Integration in InP”WG Chair: Rajeev Ram, MIT

TECHNOLOGYWORKING GROUPS

“Opto-Electronics Convergence in Silicon”WG Chair: Lionel Kimerling, MIT

“Applications for Organics in Integrated Photonic Circuits”WG Chair: Vladimir Bulovic, MIT

“Development of a Hybrid Platform for Photonic Integration”WG Chair: Dominic Goodwill, Nortel

TWGs – Gather together thought leaders, from bothindustry and academia, in particular areas ofexpertise to discuss technology evolution.

CTR TWG - A FRAMEWORK FOR DISCUSSION

s 3-D Integration of materials

s Simulation tools for OEICs

s Maturity of applications opticalclock distribution

s Immature processes for photonics

s Vastly different manufacturing fordifferent circuits (DSP v. DRAM v. Analog)

s Materials limitations emission of light

s Lack of accurate simulation tools foranything except digital

s Resistance to incorporate newfunctions

s Mature electronics applicationsand industry

s Low power dissipation CMOS

s Lower operating cost – reducefootprint and increase power efficiency

s Ease of use - interfacemanagement for customer

ACTIONSBARRIERSDRIVERS

Summary of dr ivers, barr iers and act ions for photonic integrat ion:

Silicon

10µµm

Ge SiO2

Si OptoelectronicsSi Optoelectronics

-2.0 -1.5 -1.0 -0.5 0.0 0.50

100

200

300

400

500

600

Res

pons

ivity

(mA

/W)

Bias Voltage (V)

330 mA/W with 1 µm Ge550 mA/W with 4 µm Ge770 mA/W with AR Coating

330 mA/W with 1 µm Ge550 mA/W with 4 µm Ge770 mA/W with AR Coating

p+Si+V -V

Gen+Ge

Kimerling Group, MIT

>90% quantum efficiencyIntegrated Mux and VOA

Bookham

CTR TWG - A FRAMEWORK FOR DISCUSSION

s Design for integration

s Develop standards that includetelecom and datacom

s Simulation tools for OEICs

s “Layer of Abstraction” at sub-system level

s Tools for localized thermalmanagement

s Sacrificing customization andperformance

s Lower device yields

s Lack of industry standards

s Thermal management

s Lack of simulation tools

s Breadth of resources under one roof

s Lower manufacturing costs –reduce packaging costs

s Lower operating cost – reducefootprint and increase power efficiency

s Ease of use - interfacemanagement for customer

ACTIONSBARRIERSDRIVERS

Summary of dr ivers, barr iers and act ions for photonic integrat ion:

III-V

6 section DBR LaserAgility

Opto Speed's receiver IC containsan InGaAs pin photodiodemonolithically integrated with anInP HBT-based TIA

InP OptoelectronicsInP Optoelectronics

CTR TWG - A FRAMEWORK FOR DISCUSSION

s Improvements to packagingtechnology plastic packaging

s Process development planardeposition

s Improve material stability newmaterials and processes (i.e. improvecross-linking)

s Industry perception of organics

s Materials compatibility – differentorganic materials optimized for each function.

s Material stability – index drifts with time

s Thermal management

s Limited electronic functions 100kHztransistors, no n-channel logic

s Immature process technology

s Packaging complexity – hermeticsealing

s Lower manufacturing costs – noepitaxy, no processes (ie inkjet printing)

s Large format – roll-to-rollmanufacturing

s Unique materials properties -large thermo-optic coefficient, electro-optic coefficient, dielectric constant

ACTIONSBARRIERSDRIVERS

Summary of dr ivers, barr iers and act ions for photonic integrat ion:

Organic

L. Eldada et al., Telephotonics

-30

-25

-20

-15

-10

-5

0

-0.2 -0.1 0 0.1 0.2Applied Electrical Power [W]

Nor

mal

ized

Opt

ical

Pow

er [d

B]

1x2 "OFF" (Exp.)

Three 1x2 "ON" (Sim.)

16x16 (Sim.)16x16 (Exp.)

PerformanceCharacteristics

• Insertion Loss: 4 dB• Extinction: -30 dB• Power Consumption: 4.5 W (35 mW/DOS)• PDL: 0.1 dB

N 2 N 4 N 8 N 8 N 4 N 2 N N → 2N(N-1) 1x2 ’s16 32 64 128 128 64 32 16 → 480 1x2’s

16x16 Digital OpticalSwitch Design Elements

• 480 1x2 Switches• 740 S-Bends• 227 Crossings• 8 Switching Stages• 1920 Bond Pads forper Heater Actuation• 514 Bond Pads bySerializing 4 Stages• Chip SizeOld 4x10.4 cm2 (1/6”wfr)New 4x6 cm2 (6/6”wfr)• 256 Switching States• 128 Heaters Actuatedfor 16 Paths

Polymer Polymer OptoelectronicsOptoelectronics

OEIC Roadmap for III-V Integration

Current Stage 1Near Term

Stage 3Mid Term

Stage 4Long Term

TX-RX

SOA + PIN + TIA

Laser + Mod

PIN + TIA

Laser + SOA + Mod

Driver Amp

Optical MUX

Driver + TxRx

Multi Wave TxRx

Technology

Industry

Policy

SummarySummary

Developing high performance, low-cost network elementsrequires integrating diverse optical and electronic functions

A broad industry-wide effort is underway to construct aroadmap for optoelectronic integration

Unexpected challenges…•Customer perceptions about technology

Networks differentiated by hardwareTechnology bias & insufficient standards definitions

•Diverse manufacturing lines even for same materialAnalog and digital (DSP) lines in SiliconPhotonics and electronics lines in InP