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Roadmap to 100 GbE, a CWDM Solution

IEEE 802.3 Higher Speed Study Group

IEEE 802.3 Higher Speed Study Group

Interim Meeting , Monterey CA

January 17-19, 20

Xavier Clairardin, Kotura

xclairardin@kotura.com

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Proposed SMF Study Alternative

•CWDM laser array

–Un-cooled CWDM DML array

–1430 –1610nm, 20nm spacing

–ITU G.694.2 Grid

•10 GbsPINsarray

•Existing 10 GbsElectronics

•SOI Integration platform

–Mux/ Demuxintegrated Gratings

–Automated Flip Chip bonding

–Passive Alignment

–Non herm

etic package

–Small Photonic Chip fits in Small

Form

Factor MSA such as XENPAK

•100m –10km Reach over SMF

MUX DEMUX

10xPhotodiodes

Monitoring

Photodiodes

10 x CWDM DFB

Laser Arrays

10 x TIA10 x Laser Driver

Optical Output

100 GE

Optical Input

100 GE

Electrical Output

10 x 10 GE

Electrical Input

10 x 10 GE

1550nm 10x10 G un-cooled DML CWDM array

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Leveraging Silicon Photonics

A platform

that integrates optics & electronics on the same

silicon chip using standard CMOS m

anufacturing techniques.

Electrons & Photons in Silicon

Silicon

SiO

2

p+ / n+ doped

metal

Optical beam

Array of CMOS Photonics Chips

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Silicon Allows Very Small Mux/Demux

15mm

3.5mm

15mm

7mm

•CMOS Si process

•100’s of chips per wafer

•1/10 size of a standard AWG

•Small chip fit SFF MSA such XENPAK

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Silicon DeMuxresponse over 10 CWDM channels

12nm

RX Demuxdesigned with 12nm Flat passband

•Allows 4nm for DFB registration

•Allows 8nm for variation of Demuxover 100oC

•Provides <-30dB adjacent channel x-talk.

DFB λ λλλ

registration: +/-2nm

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MuxResponse over 10 CWDM channels

6.4nm

TX Muxdesigned with broad Gaussian 6.4nm Passband

allowing 4nm for DFB registration.

5pm/oC ∆λ/∆T difference between Si and InPover Temp Range

provides for 20oC for temperature differential across chip.

High therm

al conductivity of Si provides good therm

al management

DFB λ λ λ λ registration: +/-2nm

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Waveguide Optical Coupling

•Three dim

ensional mode expander reduces waveguide coupling loss to

< 0.5 dB

•Total insertion loss of <1dB fiber-to-fiberdemonstrated

•Reduced Back facet reflection (<-50dB)

•Im

proved PDL (<0.05dB)

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-1.5

-1-0.5

00.5

11.5

-5

-4.5-4

-3.5-3

-2.5-2

-1.5-1

-0.50

Offset(um)

coupling Loss(dB)

Horizontal

Vertical

02

46

810

-3

-2.5-2

-1.5-1

-0.50

Distance(um)

coupling Loss(dB)

Coupling Loss ~ -1.2dB with passive alignment tolerance:

X±0.5um, Y ±0.3um, Z = 3um±1um

DFB Laser Coupling to a W

aveguide

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Laser Hybridization –

Automated passive alignment

Key Strengths

•Tuning capability is Key for DWDM applications

•Silicon has similar ∆n/∆T as III/V

•High therm

al conductivity enables high power dissipation and good temp control

•No compromise in perform

ance

•Low cost process

•Very high yield

Key Components

•Lasers

•Detectors

•SOAs& LOAs

•SLDs

Laser

Monitor PD

Waveguides

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Photodiode Hybridization

Active area

Pn

Absorptive area

p-n

junction collects

photo-current

Phase 1: Integrated Mirror with

Surface Mount Photodiode

Phase 2: Integrated

Power Monitor

Si Ge

Future Photodiode

Integration

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CYOPTICS CWDM Laser Array

12

MUX

Monitoring

Photodiodes

10 x CWDM DFB

Laser Arrays

10 x Laser Driver

Electrical Input

10 x 10 GE

100 GbEthernet

DEMUX

10xPhotodiodes

10 x TIA

Electrical Output

10 x 10 GE10X10 GE Link Budget Considerations

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Economic Feasibility

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Example of Photonic integration : Next Gen FTTH Triplexer

Laser: Passive

Auto-aligned

Passive Fiber

Attach

VOAs

Surface

Mount PD

Monolithically

Integrated Front

Facet Monitor

Mux/ Demux

Grating Element

Absorbers

n

Si

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10 GE Landscape

10GBASE-EW

10GBASE-ER

10GBASE-LW

10GBASE-LR

10GBASE-LX4

1310nm LAN / WWDM SMF

10GBASE-SW

850nm W

AN

Serial MMF

10GBASE-SR

850nm LAN

Serial MMF 65m

300m

10Km

40Km

1310nm LAN / WWDM M

MF

1550nm W

AN / Serial SMF

1550nm LAN / Serial SMF

1310nm W

AN / Serial SMF

1310nm LAN / Serial SMF

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100 GE Current Reach/PMD Objectives

Extended Reach

Long Reach

Interm

ediate Reach

Short Reach

MMF

100m

300m

2Km

10Km

40Km

Current Objectives

Potential Interm

ediate

SMF

SMF

SMF

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Roadmap to Lower Cost & Higher Perform

ance

Integration“D

o whatever you can in CMOS and the rest in InP,” (Infinera)

•Start with silicon m

ux/demux& hybridization platform

–Silicon Photonics: Mux/demux, Hybridization platform

–Leverage existing chip sets at 10GE: TIA’s, laser drivers

–InPplatform

: 10X10GE CWDM DFB lasers array, monitors, detectors

•Im

plement monitors in silicon

–InP: 5X 20 GE CWDM DFB laser array, detectors

–Electronic chips: commercial TIA’s, laser drivers

•Replace laser array with broad light source

•Im

plement modulators & detectors in silicon

–InP: Low cost broadband light source

Time