multi-function integrated inp-based photonic circuits · lattice constant = 5.87 a at 300k (two...

Coldren ECOC Tutorial 092308

MultiMulti--function Integrated InPfunction Integrated InP--Based Based Photonic CircuitsPhotonic Circuits

ECOCECOC’’08 Tutorial08 Tutorial

Larry A. ColdrenLarry A. ColdrenECE and Materials DepartmentsECE and Materials Departments

University of California, Santa Barbara, CA 93106 University of California, Santa Barbara, CA 93106 [email protected]@ece.ucsb.edu

Acknowledgements: Chris Doerr, Alcatel-Lucent; Chuck Joyner, Infinera; UCSB colleagues


Outline/ContentsOutline/Contents

•• Integration Platforms/TechnologyIntegration Platforms/Technology

•• TransmittersTransmitters

•• ReceiversReceivers

•• Transceivers/Wavelength ConvertersTransceivers/Wavelength Converters

•• ConclusionsConclusions


Indium Indium phosphidephosphide

Zincblende structure

Lattice constant = 5.87 A at 300K(two intersecting FCC lattices, one for In and one for P)

III-V material


InGaAsP/InPInGaAsP/InP latticelattice--matched alloysmatched alloys

InGaAsP lattice-matched to InP

λg(µm) = 1.24/ Eg(eV)1.31

1.55


Lateral waveguides/couplersLateral waveguides/couplers

Deeply-etched Ridge Surface ridge Buried ribBuried channel

Higher index contrast

InPInGaAsP

WMMI WWG

LMMI

LTUNE

PinPout

MMI coupler

Waveguide cross sections


ModulatorsModulators

Traveling-wave linear phase modulator

Electro-absorption modulator (EAM)

Can use quantum-confined Stark effect with larger ∆λ

Data

Data

~4 mm

~ 100 µm

RF and optical velocities difficult to match

Electro-absorption modulator (EAM)

(Can get away with lumped phase modulator up to ~10 GHz)(Also, current injection for < 1 GHz)

Mach-Zehnder modulator (MZM) lumped

Can use quantum-confined Stark effect for large ∆α

Data

~ 500 µm


ActiveActive--Passive (axial) IntegrationPassive (axial) Integration

VerticalVerticalTwinTwin--GuideGuide

VerticalVerticalTwinTwin--GuideGuide

Desire lossless, reflectionless transitions between sections


First integrated InP (laser First integrated InP (laser –– X) devicesX) devices

• Coupling mirrors between integrated active and passive sections

Etched grooves- Tunable single frequency- Laser-modulator- Laser-detector

L.A. Coldren, B.I. Miller, K. Iga, and J.A. Rentschler, “Monolithic two-section GaInAsP/InP active-optical-resonator devices formed by RIE,” Appl. Phys. Letts., 38 (5) 315-7 (March, 1981).

DBR gratings and vertical couplers- Tunable single frequency- Combined integration technologies

Y. Tohmori, Y. Suematsu, Y. Tushima, and S. Arai, “Wavelength tuning of GaInAsP/InP integrated laser with butt-jointed built-in DBR,” Electron. Lett., 19 (17) 656-7 (1983).

Partially transmissive mirrors


QWI For MultipleQWI For Multiple--Band Edges/Single GrowthBand Edges/Single Growth

• Simple/robust QWI process– Ability to achieve multiple band

edges with a single implant

E. Skogen et al, “Post-Growth Control of the Quantum-Well Band Edge for the Monolithic Integration of Widely-Tunable Lasers and Electroabsorption Modulators,” IEEE J. Sel. Topics Quantum Electron.


PIC TransmittersPIC Transmitters


Early PIC transmitter: EMLEarly PIC transmitter: EML

EML = electroabsorption-modulated laser

M. Suzuki, et al., J. Lightwave Technol., LT-5, pp. 1277-1285, 1987.

DFB laser EAM


Early PIC with wavelengthEarly PIC with wavelength--selectable laser selectable laser and EAMand EAM

M. G. Young, et al., Electron. Lett., 31, pp. 1835-1836, 1995.


Early PIC with widelyEarly PIC with widely--tunable laser tunable laser and EA or MZand EA or MZ--modulatormodulator

Front Mirror Gain Phase

Rear Mirror

SG-DBR Laser

AmplifierMZ Modulator

MQW active regions

Sampled gratings

Courtesy of JDSU+

UCSB

SGDBR+X: (UCSB’91-’08 Agility’99-’05 JDSU’05 )

2 0 0 k m 0 k m

10 Gb/s Optical Duobinary Transmission

L.A. Johansson, L.A. Coldren, P.C. Koh, Y.A. Akulova, and G.A. Fish, "Transmission of 10 GbpsDuobinary Signals Using an Integrated Laser-Mach Zehnder Modulator" Optical Fiber Communication(OFC), paper no. OThC4, San Diego, CA, MARCH, 2008

13dBm

16dBm

19dBm FIBER POWER

192 193 194 195 196Channel Frequency (THz)

45

50

55SMSR (dB)

-140

-150

-160

RIN (dB/Hz)

1

2

3∆ν (MHz)

SGDBR/SOA (no mod.)• Vernier sampled DBRs and phase set wavelength• External SOA controls amplitude


SGDBRSGDBR-- MachMach--ZehnderZehnder transmitter stage transmitter stage of transceiver (wavelength converter)of transceiver (wavelength converter)

DQWSeriesSeries--pushpush--pull SGDBRpull SGDBR--MZ transmitter MZ transmitter •• Integrated load R and bypass CIntegrated load R and bypass C•• 30 GHz Bandwidth30 GHz Bandwidth•• 40 Gb/s error free operation40 Gb/s error free operation•• Low/negative chirpLow/negative chirp

A. Tauke-Pedretti, M.N. Sysak, J.S. Barton, L.A. Johansson, J.W.Raring, and L.A. Coldren, “40 Gbpsseries-push-pull Mach-Zehnder Transmitter on a dual-QW integration platform,” Photon. Tech. Lett., 18(18) 1922-4 (2006).

0 km

25 km

50 km

10 Gb/s Eyes

40 Gb/s eyes Negative chirp resultMZ small-signal bandwidth

(km)

Transmitter

Receiver


40 40 Gb/sGb/s SGDBR/TWSGDBR/TW--EAMEAM

•• Integration of travelingIntegration of traveling--wave EAM designs with SGwave EAM designs with SG--DBR laserDBR laser•• Modulation efficiency 15 Modulation efficiency 15 –– 20 dB/V over the tuning range20 dB/V over the tuning range•• Open eyes at 40 Gb/s for all wavelengths Open eyes at 40 Gb/s for all wavelengths

–– 6 6 –– 10 dB extinction with 2.1V10 dB extinction with 2.1V

1533 nm

1543 nm

1559 nm

40 Gb/s NRZ

M. M. Dummer, J.Klamkin, E. J. Norberg, J. W. Raring, A. Tauke-Pedretti, and L A. Coldren, “ Periodic Loading and Selective Undercut Etching for High-Impedance Traveling-Wave Electroabsorption Modulators”, OFC’08, March, 2008.


Recent multiRecent multi--channel transmitter PICchannel transmitter PIC

Optical Outputl1... l10

10 x 10 Gb/s

CH1

CH10

VOA

Arra

yEA

M A

rray

AW

G M

ultip

lexe

r

OPM

Arra

yDC Electrical Bias and Control

10 x 10 Gb/s Electrical Input

Tuna

ble D

FBAr

ray

R. Nagarajan, et al., Sel. Top. Quant. Electron., 11, pp. 50-65, 2005. Slide courtesy of C. Joyner


MultiMulti--channel transmitter resultschannel transmitter results

0 50 100 150 200 250 300DFB Forward Current (mA)

-1.5

-1

-0.5

0

0.5

1

1.5

2

DFB

Vol

tage

(V)

Large-Scale Photonic Integrated Circuit10-Channel DW DM Transmitter

DC (20°C)

Channels 1-10

Opt

ical

Pow

er M

onito

r Pho

tocu

rren

t(a

rbitr

ary

units

)

0 50 100 150 200 250 300DFB Forward Current (mA)

-1.5

-1

-0.5

0

0.5

1

1.5

2

DFB

Vol

tage

(V)

Large-Scale Photonic Integrated Circuit10-Channel DW DM Transmitter

DC (20°C)

Channels 1-10

Opt

ical

Pow

er M

onito

r Pho

tocu

rren

t(a

rbitr

ary

units

)

-80

-70

-60

-50

-40

-30

-20

-10

0

10

1526 1530 1534 1538 1542Wavelength (nm)

Nor

mal

ized

Pow

er (d

B)

-20

-16

-12

-8

-4

0

0 1 2 3 4Negative Bias (V)

Nor

mal

ized

Tra

nsfe

r Fu

nctio

n (d

B)

-12

-9

-6

-3

0

3

0 5 10 15 20Frequency (GHz)

Nor

mal

ized

Ele

ctri

cal R

espo

nse

(dB

)

LS-PIC DWDM TransmitterEAM Frequency Response (-3V)

Channels 1-10

Nor

mal

ized

Ele

ctri

cal R

espo

nse

(dB

)

-12

-9

-6

-3

0

3

0 5 10 15 20Frequency (GHz)

Nor

mal

ized

Ele

ctri

cal R

espo

nse

(dB

)

LS-PIC DWDM TransmitterEAM Frequency Response (-3V)

Channels 1-10

Nor

mal

ized

Ele

ctri

cal R

espo

nse

(dB

)

1 2 3 4 5 6 7 8 9 10

EAM transfer function

Slide courtesy of C. Joyner


TravelingTraveling--wave MZM DQPSK PICwave MZM DQPSK PIC

CWlight

Modulatedsignal

Sub-MZMs

Q Q

I I

50-Ω termination

50-Ω termination

π/2 phase shifters

DC bias

Wavelength range: L-band (λPL = 1.47 µm)RF input: Differential

EO interaction length: 3 mm (Sub-MZMs),1.5 mm (π/2-phase shifter)

Chip size: 7.5 mm x 1.3 mm

Courtesy of N. Kikuchi

Uses novel n-p-i-nstructure

N. Kikuchi, ECOC, 10.3.1, 2007.


189.5 189.6 189.7 189.8-80

-70

-60

-50

-40

-30

-20

-10

Fi

ber o

utpu

t pow

er (d

Bm

)

Frequency (THz)

TWTW--MZM DQPSK ResultsMZM DQPSK Results

40 Gbit/s

MZDI Balancedreceiver

λ = 1580 nmLD

40 Gbit/s

Driving voltage: 3 Vpp (Vπ ) for each

data data

data data

80 Gbit/s (+π/4)

(-π/4)

Received eye patterns

(10 ps/div)

+/-π/4

Slide courtesy of N. Kikuchi


Recent InP DQPSK modulator PICRecent InP DQPSK modulator PIC

Ground pad EAM padStar coupler DC bias pad

2.2 µm

n InP

Aup+ InGaAs

p InP

i InP8 QWs

EAM #1

EAM #2

37%

37%

26%

0°

+90°

225°

Inlet width ratio chosen to achieve desired splitting

ratio

1.7 mm

BCB

Set to 90° bias by design (using extra path length in one arm)

C. R. Doerr, et al., OFC, PDP33, 2007.


DQPSK modulator resultsDQPSK modulator results

15 20 25-9-8-7

-6

-5

-4

-3

-2

OSNR (dB)

Log

(bit

erro

r rat

e)

215-1 PRBS

79.6 Gb/s (OC-1536)

Quad #1Quad #2

1554.4 1554.6 1554.8 1555 1555.2-60

-50

-40

-30

Wavelength (nm)

Pow

er (d

Bm

)

10 ps

C. R. Doerr, et al., OFC, PDP33, 2007.


ReceiversReceivers


Early PIC multiEarly PIC multi--wavelength receiverwavelength receiver

J. B. D. Soole, et. al., Electron. Lett., pp. 1289-1290, 1995.

8 × 2 nm


Optical Input

l1... l1010 x 10Gb/s

CH1

CH10PIN PhotodiodeArray

AW

G D

e-M

ultip

lexe

r

10 x 10Gb/s Electrical

Output

Recent multiRecent multi--channel receiver PICchannel receiver PIC

R. Nagarajan, et al., Sel. Top. Quant. Electron., 11, pp. 50-65, 2005.



-35

-30

-25

-20

-15

-10

-5

0

5

1528 1533 1538 1543 1548Wavelength (nm)

Nor

mal

ized

Pho

tore

spon

se (d

B)

0.0

0.2

0.4

0.6

0.8

1.0

0 1 2 3 4 5 6 7 8 9 10Channel Number

Pola

riza

tion

Dep

ende

nt L

oss (

dB)

MultiMulti--channel receiver resultschannel receiver results



T. L. Koch, et al., Electron. Lett., 25, pp. 1621-1622, 1989.

Early heterodyne receiver PICEarly heterodyne receiver PIC

Heterodyne receiverfor coherent

LO laser

Also, H. Takeuchi, et al., IEEE Photon. Tech. Lett., 1, pp. 398-400, 1989.


Balanced receiver for Balanced receiver for phase modulatedphase modulated signals signals with feedbackwith feedback——NEED for NEED for OEICsOEICs!!!!

Large-signalmodulation•Open loop•Closed loop

0

0 . 5

1

Tran

smis

sion

M Z p h a s e ( r a d )0 π 2 π

Pho

tocu

rren

t

Signal – LO phase difference

•• Signal mixed with local oscillator to demodulate optical phaseSignal mixed with local oscillator to demodulate optical phase–– Detected differential photocurrent represents signalDetected differential photocurrent represents signal--LO phase differenceLO phase difference–– Response of interferometer based demodulator is sinusoidalResponse of interferometer based demodulator is sinusoidal

•• With feedback the differential photocurrent is reduced by the loWith feedback the differential photocurrent is reduced by the loop op gain: gain: 1/(1+T1/(1+T))

–– Hybrid integrated EIC* provides transconductance amplificationHybrid integrated EIC* provides transconductance amplification–– Closely track received optical phase to operate within linear reClosely track received optical phase to operate within linear regimegime–– NEED VERY SHORT FEEDBACK PATH NEED VERY SHORT FEEDBACK PATH

is ~ sin(ϕsignal - ϕLO)

L.A. Johansson, H.F. Chou, A. Ramaswamy, L. A. Coldren, and J.E. Bowers, “Coherent optical receiver for linear optical phase demodulation,” Proc. MTT-S Microwave Sym., Tu3D-01 (June, 2007).


QWI/offset absorber PIC PM receiver QWI/offset absorber PIC PM receiver

Semi-Insulating InP substrate

n+ - InP

n+ - InPn++- InGaAs or

InGaAsP contact

p++ - InGaAs contact

n- - InGaAsP WG

p+ - InP

InP collectorp++ - InGaAs absorber

p+ - InP

MQWsQWI

Modulator Passive waveguide

UTC detector


Balanced UTCBalanced UTC--PD designPD design

Long absorption profile and wide input reduce front end saturation

BPM simulation illustrating absorption profile

4 µm wide 9 µm wide

2D overlap of mode with absorber: 2.8%

J. Klamkin, A. Ramaswamy, L. A. Johansson, H-F Chou, M.N. Sysak, J. W. Raring, N. Parthasarathy, S.P. DenBaars, J.E. Bowers, and L. A. Coldren, “High-output-saturation and high-linearity uni-traveling-carrier waveguide photodiodes,” Photonics Tech. Letts. 19 (3) 149-151 (Feb. 2007).

PD 1

PD 2

Interconnect

QW

Barrier

Absorber

1D mode profilep+ InGaAs Absorber

n-InP Collector

InGaAsP MQW and Waveguide


Linearity ResultsLinearity Results

PD B: OIP3 = 46.1 dBm at 60 mA44.2 dBm at 80 mA

Two-tone OIP3

Example IMD3 measurement

*Record OIP3 for a WG PD

I1 dB = 80 mA

Saturation currents PD B

f = 1 GHz


Phase modulator designPhase modulator design

QW

Barrier

15 QW - Γ2D = 20.7 %

V0 V

∆φ Linearized output

characteristic [∆φ(∆V) – ∆φ(-∆V)]

∆V

V0 V

∆φ

∆V

•• Linear term doubled, even order terms cancelledLinear term doubled, even order terms cancelled•• Third order distortion suppressed with bias optimizationThird order distortion suppressed with bias optimization

VπDC = 2.1 V•mm

Push-pull modulation


TranceiversTranceivers/wavelength converters/wavelength converters


1. QWI1. QWI++ widelywidely--tunable transceiver/tunable transceiver/SOASOA--PIN & SGDBRPIN & SGDBR--EAMEAM

QWI+

• Current from UTC directly modulates EAM• Only dc biases & no filters required for wavelength conv.• Any wavelength in to any out over C-band• Signal monitoring available

J.W. Raring, and L.A. Coldren, “40-Gb/s Widely Tunable Transceivers,”IEEE J. Sel. Topics Quantum Electron., 13, (1), pp. 3-14, (January/February 2007)


Widely-tunable SGDBR laser

UTC photodiode

QWIQWI--Transceiver chip elementsTransceiver chip elements•• HighHigh--gain/high gain/high PPsatsat 22--stage SOA prestage SOA pre--amps + UTC photodiode receiveramps + UTC photodiode receiver•• SGSG--DBR laser + QW EAM transmitterDBR laser + QW EAM transmitter

175µm QW EA modulator

High gain/high Psat SOA

28.5 dB gain

22.5 dB gain


QWIQWI++ transceiver 40 transceiver 40 Gb/sGb/s transmit and transmit and receive functionalityreceive functionality

–– Transmitter: 175Transmitter: 175µµm EAM m EAM –– DC = 2.5DC = 2.5--4.5V: 4.5V: VVPtoPPtoP = 2.5= 2.5–– Receiver: 400 Receiver: 400 µµm m highhigh--gain SOA with gain SOA with

4040µµm UTC m UTC


2. Wavelength converter/SOA2. Wavelength converter/SOA--PIN receiver &PIN receiver &SGDBRSGDBR--Mach Mach ZehnderZehnder transmittertransmitter

•• Photocurrent drivenPhotocurrent driven•• 35 35 µµm m QW absorption region in receiverQW absorption region in receiver

–– Tapered for reduced capacitanceTapered for reduced capacitance•• 300 300 µµmm travelingtraveling--wave Machwave Mach--Zehnder modulation regionZehnder modulation region

–– SeriesSeries--pushpush--pull design to maximize bandwidthpull design to maximize bandwidth•• Data format and rate transparentData format and rate transparent•• No optical filter requiredNo optical filter required•• IntegratedIntegrated termination resistor and bypass Capacitortermination resistor and bypass Capacitor

–– No external bias tees usedNo external bias tees used


Simple offset QW integration platformSimple offset QW integration platform

Active PassiveInGaAs p-contact

p-InP

7 – Quantum Wells

1.4 Q InGaAsP WG

n-InP

InGaAs n-contact

Fe dopedInP substrate

n-InP

Use simplest integration platform to do the job

•• Receiver SOAReceiver SOA–– Offset quantum wells provide gain (23 dB achieved)Offset quantum wells provide gain (23 dB achieved)–– Linearly flared waveguide (16 Linearly flared waveguide (16 dBmdBm PPsatsat))–– 13 13 dBmdBm (20mW) (20mW) 1 V 1 V rmsrms (2.8 (2.8 VVpppp) over 50 ) over 50 ΩΩ

•• QuantumQuantum--well PIN detectorwell PIN detector–– Reverse biased laser QW provide high absorption Reverse biased laser QW provide high absorption

coefficientcoefficient–– Wide front end prevents saturationWide front end prevents saturation–– Tapering reduces capacitanceTapering reduces capacitance

A. Tauke-Pedretti, M.M. Dummer, M.N. Sysak, J.S. Barton, J.W. Raring, J. Klamkin, and L.A. Coldren, “Monolithic 40 Gbps Separate Absorption and Modulation Mach-Zehnder Wavelength Converter,” Proc. OFC, paper no. PDP36, Anaheim, CA (March 25-29, 2007)


MachMach--Zehnder Wavelength ConverterZehnder Wavelength Converter

DQW

1529 nm 1545 nm

1561 nm Back to back

Constant input to varying output Varying input to constant output

WC PerformanceWC Performance•• 40 Gb/s NRZ operation40 Gb/s NRZ operation•• <2.5 power penalty for varying input <2.5 power penalty for varying input

and output wavelengthsand output wavelengths

A. Tauke-Pedretti, M.M. Dummer, M.N. Sysak, J.S. Barton, J. Klamkin, J.W. Raring and L.A. Coldren, “Separate Absorption and Modulation Mach-Zender Wavelength Converter,” J. LightwaveTech., 26, (1), 91-98 (Jan. 2008)

Current from absorber drives SPP-MZM


4. SOA4. SOA--PIN & SGDBRPIN & SGDBR--TW/EAM TW/EAM wavelength converterwavelength converter

• Data format and rate transparent 5-40Gb/s• No filters required (same λ in and out possible)• On-chip signal monitor• Two-stage SOA pre-amp for high sensitivity, efficiency and linearity• Traveling-wave EAM with on chip loads• Only DC biases applied to chip• 40 nm wavelength tuning range

M. Dummer et al. OFC 2008 OThC6 (2008), and Invited paper, ECOC 2008.


SGDBR/TWSGDBR/TW--EAM WC RF/DATA EAM WC RF/DATA CharacteristicsCharacteristics

Bit-Error-Rate

Wavelength converted (1560 to 1548 nm) bit error ratio (open symbols) compared with back-to-back transmission (solid symbols) (1548 nm) for PRBS 231-1 data at various bit rates

Eye Diagrams


5. SOA5. SOA--MZI Wavelength Converter MZI Wavelength Converter PICsPICs::40 40 Gb/sGb/s Packet Forwarding Chip Packet Forwarding Chip

Output 1550nm

•• Fast Tunable SGDBR LaserFast Tunable SGDBR Laser•• Differential MachDifferential Mach--ZehnderZehnder Interferometer SOA Wavelength Converter (Interferometer SOA Wavelength Converter (‘‘allall--opticaloptical’’))•• Preamplifier Preamplifier SOAsSOAs•• Integrated delayIntegrated delay

V. Lal, M. L. Masanovic, J. A. Summers, G. Fish, and D. J. Blumenthal, "Monolithic Wavelength Converters for High-Speed Packet-Switched Optical Networks," JSTQE, 13, pp. 49-57, 2007.

OQW & ButtOQW & Butt--joint regrowthjoint regrowth


6. Tunable wavelength converter 6. Tunable wavelength converter using AWGusing AWG--laser + SOA + filterlaser + SOA + filter

•• FastFast--tunable 40G wavelength converter tunable 40G wavelength converter –– 88--channel multichannel multi--frequency laser (MFL)frequency laser (MFL)–– λλ--conversion via conversion via nonlinear SOAnonlinear SOA and delay filterand delay filter

SOA

SOA Array

WC-SOA MZI

lj j = 1..8

lsig lsig & lj

InP

WC

Laser

6.5 mm

4.0

mm

Converted optical eye diagram at 40 Gb/s

MFL

WC

P. Bernasconi, et al., PDP16, OFC 2005. Slide courtesy of P. BernasconiAlcatel-Lucent—IRIS Project


Packet Switching TechnologyPacket Switching Technology


0.5mm

7mm

λinput = λoutput

λinput ≠ λoutput

Back-to-Back

22--Stage Tunable Wavelength ConvertersStage Tunable Wavelength Converters

OFC 2007: OThT2: Monolithically Integrated Multi-Stage All-Optical 10Gbps Push-Pull Wavelength Converter, Joseph A. Summers, Milan L. Masanovic, Vikrant Lal, Daniel J. Blumenthal

• First stage generates known out of band wavelength to avoid need for filters and provide known input wavelength to output stage for improved efficiency


Variable Length Packets and Dynamic Forwarding

Packet Forwarding Chip (PFC) Packet Forwarding Chip (PFC) -- Packet Packet λλ--Conversion Conversion and Optical Label Reand Optical Label Re--WriteWrite

Output λ2A C E G I

Output λ1

B D F H JiMix 7:4:1 -> 40B:570B:1500B

1500B

A B C D E F G H I J

Guard Band 40B

570B

Input

WC 8ns 40GNew 10G OL



10G Optical Header Re-Write

~10 ps Delay Line

Fast Tunable Laser

Signal Power Control SOAs

Pump Power Control SOA

Pump/Signal Combiners

XPM SOA ’s

Label Write MZ Phase

7 mm

0.75

mm

Signal Splitter

Chip Area = 5.25 mm2

“Monolithic Widely Tunable Optical Packet Forwarding Chip in InP for All-Optical Label Switching with 40 GbpsPayloads and 10 Gbps Labels,” V. Lal, M. Mašanović, D. Wolfson, G. Fish, C. Coldren, and D. J. Blumenthal, Postdeadline Paper, ECOC 2005 Glasgow, Scotland.


InP/Silicon Ring MLL and All-Optical Clock Recovery

Mode locked laser with III-V quantum wells wafer bonded to silicon waveguides

All-optical clock recovery with significant retiming and reshaping30 Gb/s 231-1 PRBS data input, 30 GHz clock outputInput wavelength insensitive14 ps input jitter, 1.7 ps output jitter

4 dB input ER, >10 dB output ER

“A Racetrack Mode-Locked Silicon Evanescent Laser,” A. Feng, et. al., Optics Express, http://www.opticsexpress.org/abstract.cfm?id=149007

“All-Optical Clock Recovery with Retiming and Reshaping Using a Silicon Evanescent Mode Locked Ring Laser,” OFC 2008, Brian R. Koch1, Alexander W. Fang1, Henrik N. Poulsen1, Hyundai Park1, Daniel J. Blumenthal1, John E. Bowers1, Richard Jones2, Mario J. Paniccia2, Oded Cohen3; 1Univ. of California at Santa Barbara, USA, 2Intel Corp., USA, 3Intel Corp., Israel.


Hybrid Hybrid InPInP/Si Switch & /Si Switch & Photonic Chip BufferPhotonic Chip Buffer

• InP Chip Insertion loss– Fiber-to-fiber gain : 2 dB

• Extinction ratio > 38 dB• Switching time (longest SOA)

– Rise time < 750 ps– Fall time < 1ns

• Silica on silicon chip– 0.04 dB/cm loss– Butt-coupled to switch– 450 cm (23ns)– PDL : 1 dB– CD : 130ps/nm-km

Switch: InP

Delay loop: SiO2

Burmeister, Bowers, PTL 18(1).


40 40 Gb/sGb/s Switch & Buffer PerformanceSwitch & Buffer Performance

Pre-amplified receiverBERT

Tx40 Gb/s RZ PRBS 231-1

1550 nm

1.2 nm BFRx

TEC

• Power penalty at 1e-9 BER• Dynamic range : 15dB• With <2 dB power penalty

• Negative power penalty• Gain from the amplifiers• ASE reduced by filter

Burmeister et al. Optics Express (2008).

SWITCH

• Packets contain 64 bit identifier strings

• 5 circulations, or 64 ns of delay with 98% packet recovery

• More circulations possible with less loop loss, lower noise figure

BUFFER


ConclusionsConclusions

•• MultiMulti--functionality InPfunctionality InP--based Photonic ICs can based Photonic ICs can now be made with statenow be made with state--ofof--thethe--art performance art performance and reductions in power dissipation, size, and and reductions in power dissipation, size, and perhapsperhaps cost in sufficient numbers. cost in sufficient numbers.

•• MultiMulti--channel WDM transmitters, receivers, channel WDM transmitters, receivers, and wavelength converters demonstratedand wavelength converters demonstrated

•• Many future Many future PICsPICs now on the now on the ‘‘drawing boarddrawing board’’

multi-function integrated inp-based photonic circuits · lattice constant = 5.87 a at 300k (two...

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