Generation and Optical Processing of 100of 100-GBd QAM ......Generation and Optical Processing of...

FraunhoferHeinrich Hertz InstituteFraunhofer

Heinrich-Hertz-Institut

Generation and Optical Processing of 100 GBd QAM Signalsof 100-GBd QAM Signals

Thomas Richter

[email protected]

Fraunhofer Heinrich Hertz Institute, Einsteinufer 37, 10587 Berlin www.hhi.fraunhofer.de

PhotonicNetworks and SystemsAcknowledgment

Research projects

SASER M ltiR FOPASASER MultiReg FOPA

All my collegues of the Submarine and Core Systems Group at Fraunhofer HHI

Lars Grüner Nielsen, OFS Denmark

ISUPT2013, RochesterOctober 21, 2013

Thomas Richter 2©

PhotonicNetworks and SystemsOutline

Introduction

Generation of 107-GBd QAM signals Generation of 107-GBd QAM signals Concept Experimental Results for BPSK/QPSK/16QAMExperimental Results for BPSK/QPSK/16QAM

Processing of 107-GBd QAM signals:All-optical Phase RegenerationAll-optical Phase Regeneration Concept Experimental Results for Nyquist-BPSKExperimental Results for Nyquist BPSK

Conclusions


Thomas Richter 3©

PhotonicNetworks and Systems

State-of-the-Art High-Speed Serial Systems Serial line rates in coherent systems

• Today’s commercial ~ 30-GBd QPSK (16QAM)• Lab (ETDM) 56-GBd 16QAM [Winzer, ECOC2010, PDP]

107-GBd 16QAM [Raybon, ECOC2013,PDP]

L b (T /R OTDM) 1274 GBd 16QAMx 10

• Lab (Tx/Rx-OTDM) 1274-GBd 16QAM [Richter, JLT 30(4) 2011]

Title of today’s talky“Generation and Optical Processing of 100-GBd QAM signals”• QAM-signals with high quality are preferred• ETDM system offer rather limited quality at ~100 GBd

Realization of high-quality 107-GBd QAM system


Thomas Richter 4©

g q y y

PhotonicNetworks and Systems107-GBd QAM-system: Key aspects

I/Q-mod. rate 53.5 GBd

Tx-OTDM2-fold

opt. Nyquistopt. Nyquistpulse-shapingcomm. avail. Rx-ADC

>120-GHz opt. BW


Thomas Richter 5©

PhotonicNetworks and Systems107-GBd System

107-GBd Nyquist BPSK/QPSK/16QAM Transmitter

53.5 GHz,33%-RZ 53.5 GBd 107 GBd

Nyquistshaping

CW MZM I/Q-Mod PS-OMUX OF

26.75 GHzclock

phase-stable53.5 GBd 107 GBddelay = 63 5 symbols

C-band~100 kHz

electrical 53 5 GBd delay = 63.5 symbols1178.1ps

electrical 53.5-GBddriving signals

2-ChannelBPG

(215-1)

D1

D2

to IQ-Mod

00 m

W/D

IVGeneration of the IQ-Mod driving signals: BPSK/QPSK

2-ChannelBPG

(215-1)

D1

D2

/D1

1

2

6dB

00 m

V/D

IV

to IQ-Mod

Generation of the IQ-Mod driving signals: 16QAM

(2 1)

BPSK: 0=0 bit, QPSK: 0=169 bit18.7 ps

90 (2 1)/D2 3

16QAM: 1=47 bit, 2=1071 bit, 3=1024 bit

6dB 10

18.7 ps


Thomas Richter 6©



53.5 GHz,33%-RZ 53.5 GBd 107 GBd

Nyquistshaping


26.75 GHzclock

phase-stable53.5 GBd 107 GBddelay = 63 5 symbols

C-band~100 kHz

electrical 53 5 GBd delay = 63.5 symbols1178.1ps


2-ChannelBPG

(215-1)

D1

D2

to IQ-Mod

00 m

W/D

IVGeneration of the IQ-Mod driving signals: BPSK/QPSK

2-ChannelBPG

(215-1)

D1

D2

/D1

1

2

6dB

00 m

V/D

IV

to IQ-Mod

Generation of the IQ-Mod driving signals: 16QAM

(2 1)

BPSK: 0=0 bit, QPSK: 0=169 bit18.7 ps

90 (2 1)/D2 3

16QAM: 1=47 bit, 2=1071 bit, 3=1024 bit

6dB 10

18.7 ps


Thomas Richter 7©



53.5 GHz,33%-RZ 53.5 GBd 107 GBd

Nyquistshaping


26.75 GHzclock

Phase-stable53.5 GBd 107 GBddelay = 63 5 symbols

C-band~100 kHz

electrical 53 5 GBd

Broadband Coherent Receiver63 GH

delay = 63.5 symbols1178.1ps


ADC OfflineProcessing

~63 GHz160 GS/sOSNR

VOASignal

~50 GHz

DSPBERADC

90o

Hybrid

LOCWMonitoring


Thomas Richter 8©

PhotonicNetworks and Systems107-GBd: Spectra w/o & w/ Nyquist


Thomas Richter 9©


BPSK107-GBd RZ

107-GBd Nyquist

-10

0

in d

B

-20

tive

pow

er i

120 GHz

100 50 0 50 100

-30rela

t

-100 -50 0 50 100norm. frequ. in GHz


Thomas Richter 10©


BPSK107-GBd RZ

107-GBd Nyquist

QPSK107-GBd RZ

107-GBd Nyquist53.5-GBd NRZ

-10

0

-10

0

in d

B

-20

10

125 GHz-20

tive

pow

er i

120 GHz

100 50 0 50 100

-30

100 50 0 50 100

-30rela

t

-100 -50 0 50 100norm. frequ. in GHz

-100 -50 0 50 100norm. frequ. in GHz


Thomas Richter 11©


BPSK107-GBd RZ

107-GBd Nyquist

QPSK107-GBd RZ

107-GBd Nyquist53.5-GBd NRZ

16QAM107-GBd RZ

107-GBd Nyquist

-10

0

-10

0

-10

0

in d

B

-20

10

125 GHz-20

10

122 GHz-20

tive

pow

er i

120 GHz

100 50 0 50 100

-30

100 50 0 50 100

-30

122 GHz

100 50 0 50 100

-30rela

t

-100 -50 0 50 100norm. frequ. in GHz

spectrally well-confined within ~125 GHz (20-dB bandwidth)

-100 -50 0 50 100norm. frequ. in GHz

-100 -50 0 50 100norm. frequ. in GHz


Thomas Richter 12©

PhotonicNetworks and Systems107-GBd: Optical Envelopes

QPSK 16QAMBPSK

18.7 ps

53.5-GBd33%-RZ

9.35 ps

107-GBdRZRZ

9.35 ps107-GBdNyquist


Thomas Richter 13©

(measured using an optical sampling oscilloscope with > 500-GHz bandwidth)

PhotonicNetworks and Systems107-GBd: BER Performance

BPSK

2

R)

4

3

-log(

BE

R

10 12 14 16 18 206

5 theory 107-GBd BPSK

OSNR in dB

~0.5 dBimplementation penalty at 1x10-3


Thomas Richter 14©

implementation penalty at 1x10


QPSKBPSK

2

R)

2

R)

4

3

theory

-log(

BER

4

3

-log(

BE

R

12 14 16 18 20 22 246

5 107-GBd QPSK

theory

10 12 14 16 18 206


OSNR in dB


OSNR in dB

~1.5 dB


Thomas Richter 15©



QPSK 16QAMBPSK

2

R)

2

R)

2

R)

4

3

-log(

BE

R

4

3

theory

-log(

BER

4

3

-log(

BE

R

18 21 24 27 30 33 36 396

5107-GBd 16QAMtheory

12 14 16 18 20 22 246

5 107-GBd QPSK

theory

10 12 14 16 18 206


OSNR in dBOSNR in dB


OSNR in dB

Error floor at ~ 10-4 ~1.5 dB


Thomas Richter 16©


PhotonicNetworks and SystemsConclusions: 107-GBd System

107-GBd BPSK/QPSK/16QAM

107 GBd Receiver 107-GBd Receiver• Single broad-band receiver (>120 GHz optical BW)• Standard DSP (offline processing)

• 107-GBd Transmitter• 53.5-GBd ETDM• Conventional 33%-RZ pulse carving• Phase-stabilized optical time-division multiplex (x2)

Well-suited test-bed for 107-GBd signal processing

• Optical Nyquist-shaping for tight spectral confinement


Thomas Richter 17©

PhotonicNetworks and SystemsOutline

Introduction

Generation of 107-GBd QAM signals Generation of 107-GBd QAM signals Concept Experimental Results for BPSK/QPSK/16QAMExperimental Results for BPSK/QPSK/16QAM

Processing of 107-GBd QAM signals:All-optical Phase RegenerationAll-optical Phase Regeneration Concept Experimental Results for Nyquist-BPSKExperimental Results for Nyquist BPSK

Conclusions


Thomas Richter 18©

PhotonicNetworks and SystemsProcessing of 107-GBd signals

High-speed + QAM increased OSNR requirementincreased OSNR requirement increased sensitivity to impairments

(e.g from inline-amplication, optical filtering, nonlinearities)

reduced reach

Ways out ?y improved Tx/Rx-DSP, improved FEC-codes usage of o/e/o regeneration / shorter o/e/o intervals all-optical in-line regeneration


Thomas Richter 19©

PhotonicNetworks and SystemsFocus: PSA

Phase-sensitive amplifiers (PSA) using fiber-optic parametric amplifiers

L i (1R)• Low-noise (1R)• Phase-regenerative (2R+)

A few references on 2R+ A few references on 2R+...• K. Croussore, JSTQE, 14(8), pp. 2003 • R. Slavik, Nature Photon. 4, 2010• J Kakande ECOC 2010 PD 3 3• J. Kakande, ECOC 2010, PD 3.3

Reports on BPSK/QPSK NRZ-signals ≤ 56 GBd

Here: Focus will be on 107-GBd Nyquist-BPSK 2 phase states (0, ), Nyquist-pulse-shape envelope


Thomas Richter 20©

PhotonicNetworks and SystemsPSA: Principle

Pump1 Pump2dual-pump fiber-optical PSAFour-Wave Mixing (FWM)

SignalSignal*

Signal

Pump1

ωωS ωP2ωP1

g

Pump2HNLF

S* = P1 + P2 - S

E ~ A e+jS + A e-jSEout ~ AS e+jS + AS* e jS


Thomas Richter 21©

PhotonicNetworks and SystemsPSA: Complex-field illustration

2

Ratio(Signal*/Signal) 0 Pump1 Pump2

Four-Wave Mixing (FWM)

As* = 0( ti A /A 0)

As=1, s = {0 ... }

0

1

( g g )

ture Signal

Signal*

Im{E }

(ratio As*/As = 0)

-1

0

quad

ra

ωωS ωP2ωP1

Im{Eout}

-2 -1 0 1 2-2

inphase

S* = P1 + P2 - S

Re{E t} E ~ A e+jS + A e-jSpRe{Eout} Eout ~ AS e+jS + AS* e jS

No Signal* no phase-sensitive behaviour


Thomas Richter 22©


2

Ratio(Signal*/Signal) 0

Pump1 Pump2


As* = As( ti A /A 1)

As=1, s = {0 ... }

0

1

( g g ) 1

ture Signal

Signal*

Im{E }

(ratio As*/As = 1)

-1

0

quad

ra

ωωS ωP2ωP1

Im{Eout}

-2 -1 0 1 2-2

inphase

S* = P1 + P2 - S


With Signal* PS-gain for in-phase componentPS tt ti f th d t t


Thomas Richter 23©

PS-attenuation for the quadrature component


2


Pump1 Pump2



As=1, s = {0 ... }

0

1

( g g ) 1

ture Signal

Signal*

Im{E }

(ratio As*/As = 1)

-1

0

quad

ra

ωωS ωP2ωP1

Im{Eout}

-2 -1 0 1 2-2

inphase

S* = P1 + P2 - S




Thomas Richter 24©



2


Pump1 Pump2



As=1, s = {0 ... }

0

1

( g g ) 1

ture Signal

Signal*

Im{E }

(ratio As*/As = 1)

-1

0

quad

ra

ωωS ωP2ωP1

Im{Eout}

Ph i-2 -1 0 1 2

-2

inphase

S* = P1 + P2 - S

Re{E t} E ~ A e+jS + A e-jS

Phase squeezing

pRe{Eout} Eout ~ AS e+jS + AS* e jS



Thomas Richter 25©


PhotonicNetworks and SystemsExperiment:

Black-box Coherent107-GBdNyquist PM PSA ReceiverNyquistBPSK

PM

broadbandelectr. noise


Thomas Richter 26©

PhotonicNetworks and SystemsSet-up: PSA

OUTPump2 HNLFSlave

LaserPump- OUT

IN PZT

10%

CW

SOA WDM WDM

PD

10%

Pump-Locking PSA-Stage

PD


Thomas Richter 27©

PhotonicNetworks and SystemsSet-up: PSA – Pump locking

OUTPump2 Slave

Laser250 mA OUT

PZT

10%

CW

WDM WDM

10%

PSA-StageIN

SOA

P(pump1) ≈ - 5 dBm

Pump1 (100 kHz)

P(data signal) ≈ -16 dBm


Thomas Richter 28©


OUTPump2 Slave

Laser250 mA OUT

PZT

10%

CW

WDM WDM

10%

PSA-StageIN

SOA

P(pump1) ≈ - 5 dBm 10

20

Pump1 (100 kHz)

pump1P(data signal) ≈ -16 dBm

-20

-10

0

wer

in d

Bm

pump1107-GBd

BPSK

1550 1552 1554 1556 1558 1560-50

-40

-30po

w


Thomas Richter 29©

wavelength in nm


OUTPump2 Slave

Laser250 mA OUT

PZT

10%

CW

SOA WDM

10%

PSA-StageIN

WDM

Pump1 (100 kHz)

pump1pump2

Generation of a phase-locked dual-pump configuration by modulation stripping

107-GBdBPSK

and optical injection locking


Thomas Richter 30©

PhotonicNetworks and SystemsSet-up: PSA – HNLF

OUTPump2 HNLFSlave

Laser250 mA OUT

10% SOA WDM

10%

PD

IN PZTCW

WDM

OPLL-Circuit PD

HNLF

Pump1 (100 kHz)

OPLL- L=189 m, = 7.5 (W km)-1

- Al-doping & strain for suppressionof stim Brillouin scattering

- Sets the PSA operation point to achieve gain or attenuation

of stim. Brillouin scattering PSBS > 31 dBm- Compensates relative phase drifts

within the pump-locking stage


Thomas Richter 31©

PhotonicNetworks and SystemsResults: PSA – HNLF input

30R 0 01

1020

Bm

P(P1+P2) ~ 30 dBm

Res: 0.01 nm

107 GBd

20-10

0

wer

in d

B pump1107-GBdBPSKpump2

40-30-20

pow

1545 1550 1555 1560-40

wavelength in nm


Thomas Richter 32©

PhotonicNetworks and SystemsResults: PSA – HNLF output

30R 0 01

OPLL set for max-Gain

1020

Bm

Res: 0.01 nm PSA-input

20-10

0

wer

in d

B

PSA-gain(ON/OFF)

40-30-20

pow

( )

~ 5.3 dB

HNLF-loss

1545 1550 1555 1560-40

wavelength in nm

~ 4 dB


Thomas Richter 33©

PhotonicNetworks and SystemsResults: PSA – HNLF output

30

OPLL set for max-GainOPLL set for min-Gain (=max.Att.)

R 0 01

1020

Bm

PSA-input

Swing

Res: 0.01 nm

20-10

0

wer

in d

B ~ 20 dB

PSA-gain(ON/OFF)

40-30-20

pow

( )

~ 5.3 dB

HNLF-loss

1545 1550 1555 1560-40

wavelength in nm

~ 4 dB


Thomas Richter 34©


Results: 107-GBd Nyquist-BPSK IN/OUT

PSA preserves the Nyquist pulse-shape of the input signal !p yq p p p g(as also expected for unsaturated operation)

Bl k bBlack-boxPSA OUTIN


Thomas Richter 35©

PhotonicNetworks and SystemsResults: Phase-squeezing

increase in magnitude of applied broadband phase noiseincrease in magnitude of applied broadband phase noise

beforePSAPSA

after PSA

Phase distributionbefore PSA

202

er/b

efor

eto

r in

dB

A lit d-20-10

0

ty in

dB

after PSAbef.PSA (undegr.)

0.0 0.1 0.2 0.3 0.4 0.5

-6-4-2

Phase

atio

STD

afte

he re

gene

rat Amplitude

90 60 30 0 30 60 90-60-50-40-30

prob

abili

t


Thomas Richter 36©

ra th phase-STD of degraded signal-90-60-30 0 30 60 90

phase error in deg

PhotonicNetworks and SystemsResults: 4-Level Phase-Regeneration

107 GBd PSA107-GBdQPSK

107-GBdstar-8QAM PSA


Thomas Richter 37©

PhotonicNetworks and SystemsConclusion

Phase-regeneration in PSA has been applied to Nyquist-shaped signals Up to 6-dB phase-squeezing was achieved at 107-GBd

with Nyquist-BPSK Processing of more complex formats possible in modifiedProcessing of more complex formats possible in modified

PSA configurations

The investigations have been enabled by the presented107-GBd system• 53 5 GBd ETDM + 2 f ld OTDM• 53.5-GBd ETDM + 2-fold OTDM• 126-GHz coherent receiver• Modest implementation penalties for BPSK/QPSK/16QAM


Thomas Richter 38©

Modest implementation penalties for BPSK/QPSK/16QAM

FraunhoferHeinrich Hertz InstituteFraunhofer

Heinrich-Hertz-Institut

Generation and Optical Processing of 100 GBd QAM Signalsof 100-GBd QAM Signals

Thomas Richter

[email protected]

Fraunhofer Heinrich Hertz Institute, Einsteinufer 37, 10587 Berlin www.hhi.fraunhofer.de


Results: PSA – signal power atPSA output w/ & w/o phase-locking

5

OPLL-settingfor max.Gain OPLL OFF

(slow power fluctuations)

5

0

n dB

-10

-5

pow

er in

OPLL-settingfor max.Gain

-20

-15

rela

tive

OPLL-setting

0 10 20 30 40 50-25

time in s

OPLL-settingfor min.Gain


Thomas Richter 40©

time in s

PhotonicNetworks and SystemsPhase-regenerative PSA for QAM

Richter, IEEE Ph t i S i t

4-PAM2ASK BPSK Photonics Society

Summer TopicalConference 2013

PSA2ASK-BPSK

(20 GBd)

Star-8QAMRichter, ECOC 2013,We.3.A.2

PSA(25-GBd)


Thomas Richter 41©

PhotonicNetworks and SystemsBPSK-PSA: Complex-field illustration

Pump1 Pump2Four-Wave Mixing (FWM)

2 0 0.2Ratio(Signal*/Signal)ratio As*/As ↑

As=1, s = {0 ... }

SignalSignal*

0

10.4 0.6 0.8 1

ture

( g g )

Im{E }

ratio As*/As ↑

ωωS ωP2ωP1

-1

0

quad

raIm{Eout}

Ph i S* = P1 + P2 - S-2 -1 0 1 2

-2

inphaseRe{E t} E ~ A e+jS + A e-jS

Phase squeezing

pRe{Eout} Eout ~ AS e+jS + AS* e jS

Phase-squeezing strength is dependent on the FWM-efficiency


Thomas Richter 42©

q g g p y

Generation and Optical Processing of 100of 100-GBd QAM ......Generation and Optical Processing of...

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