HIGH CAPACITY OPTICAL FIBER TRANSMISSION EXPERIMENTS USING MULTIPLE MODES Dr. V.A.J.M. Sleiffer MSc

May 13th 2015

11:30-11:55

Communication networks beyond the capacity crunch - further discussion The Royal Society at Chicheley Hall, home of the Kavli Royal Society International Centre, Buckinghamshire

ACKNOWLEDGEMENTS

• Dr. Maxim Kuschnerov (Coriant)

• Dr. Yongmin Jung (ORC)

• Paolo Leoni (Universität der Bundeswehr München)

• Dr. Haoshuo Chen (Formerly TU/e, now with Bell Labs)

• Dr. Huug de Waardt (TU/e)

• Prof. David Richardson (ORC)

• All partners from the MODEGAP project

OVERVIEW

Introduction

Few-mode fiber (FMF) experiments

Hollow-core photonic bandgap fiber (HC-PBGF)

Field demonstration of MDM upgrade scenarios

Conclusions and remarks

INTRODUCTION

• Increasing data traffic (~2 dB/year)

• Current transmission medium, the single mode fiber, is reaching its limits

– Fiber nonlinearity limits maximum received OSNR

– Higher-order modulation formats have high OSNR requirements AND are more sensitive to nonlinear effects

– Limitation of maximum capacity for a certain reach

• Cost per bit and energy efficiency important drivers for new technology

R.J. Essiambre et al., “Capacity limits of Optical Fiber Networks,” JLT 28, pp. 662-700 (2010)

INTRODUCTION

• Capacity? Fiber nonlinearity, number of cores/modes, transmission window

• Reach? Fiber attenuation and nonlinearity, amplification technologies

• Cost/energy efficiency? Higher-order modulation, information density

• Amplification

• Routing

• Space-division multiplexing (SDM) and mode-division multiplexing (MDM)

Single-mode fiber ribbon

= Single-mode fiber

Multi-core fiber/ Coupled-core fiber

Few-/Multi-mode fiber

THE MODEGAP PROJECT

• Advantages w.r.t. other space-division multiplexing (SDM) technologies

– Highest information density per µm2 allows for a high level of integration

– Lowest expected overall system costs and highest energy efficiency (integrated amplifiers and ROADMs)

– Easy handling/splicing

• Hollow-core photonic band gap fiber (HC-PBGF):

– Lowest nonlinearity

– Lowest potential loss @2µm

– Highest available bandwidth @2µm

– Multi-mode?

F. Poletti et al., “Hollow-core photonic bandgap fibers: technology and applications,” Nanophotonics, vol. 2, no. 5-6, pp. 315–340, Nov. 2013.

×2.5

×4

×10

OVERVIEW

Introduction

Hollow-core photonic bandgap fiber (HC-PBGF)

Field demonstration of MDM upgrade scenarios

Conclusions and remarks

FMF experiments

FEW-MODE FIBER EXPERIMENTS

DAC

DAC

ODD

AWG

DAC

DAC

EVEN

AWG

2810

Symbols

4402

Symbols

Mode MUX

LP11B

LP11A

LP01

LP11A

Sco

pe

1S

co

pe

2Coherent

Rx

Coherent

Rx

Coherent

Rx

FM-EDFA

84km 35km

Span 2Span 1

357

SymbolsDAC

DAC

CUT

LO

1x4

48

48

WSS

0.4nm

0.4nm

0.4nm

Syn

c.

LP11B

LP01

Mode DEMUX

Mo

du

lati

on

DP

+W

DM

FMF-link MDM

Coherent reception and 6×6 MIMO-DSP

Here we only use 2 mode-groups / 3 modes: LP01, LP11A and LP11B

HIGH-CAPACITY TRANSMISSION OVER FMF

• Total 73.7 Tb/s (96 × 3 × 256) over 119 km of FMF

• Net datarate 57.6 Tb/s (taking into account FEC-overhead+Network protocols)

• Reach limitation due to mode (de)multiplexer loss

96 WDM channels FEC-limit

V.A.J.M. Sleiffer et al., “73.7 Tb/s (96 x 3 x 256-Gb/s) mode-division-multiplexed DP-16QAM transmission with inline MM-EDFA”, Optics Express 20 (26), B428-B438 (2013)

256 Gb/s

256 Gb/s

256 Gb/s

LONG-HAUL TRANSMISSION OVER FMF

• 3 MDM × 128-Gb/s DP-QPSK channel

• 60-km FMF (DMD minimized)

• 2 FM-EDFAs

V.A.J.M. Sleiffer et al., “An optical chopper based re-circulating loop for few-mode fiber transmission”, Optics Letters 39 (5), 1181-1184 (2014)

Tx

Rx

Beam diameter ≈ 0.6mm

Loop in

Loop o

ut

Tx

RxTim

ing

Contro

l

Chopper

3dB coupler

loop

60km

Spool 1 Spool 2

Length [km] 30 30

DGD [ps/m] -0.044 0.053

Average BER

Signal 1

Signal 2

Signal 3

FEC-limit

0 100 200 300 400 500 60010

-5

10-4

10-3

10-2

Transmission Distance [km]

Bit-e

rror

ratio

400 500 600 700 800 900 1000 1100 1200

10-4

10-3

10-2

Transmission Distance [km]

Bit-e

rror

ratio

10-5

FEC-Limit

LP01LP11bLP11a

Average BER 3 MDM × 128-Gb/s

DP-QPSK

Pol. X

Pol. Y

LP11a LP11b LP01

LONG-HAUL TRANSMISSION OVER FMF

V.A.J.M. Sleiffer et al., “An optical chopper based re-circulating loop for few-mode fiber transmission”, Optics Letters 39 (5), 1181-1184 (2014)

V.A.J.M. Sleiffer et al., “480 km Transmission of MDM 576-Gb/s 8QAM using a Few-Mode Re-circulating Loop”, IEEE Photonics Conference, Bellevue WA, PD6(2013)

Mode-selective launch Mode-mixed launch

LONG-HAUL TRANSMISSION OVER FMF

• Impulse response grows due to DGD/DMD!

– Important for DSP requirements

– Important for non-linear effects?

V.A.J.M. Sleiffer et al., “480 km Transmission of MDM 576-Gb/s 8QAM using a Few-Mode Re-circulating Loop”, IEEE Photonics Conference, Bellevue WA, PD6 (2013)

100 150 200 250 300 350 400

10-4

10-3

10-2

Number of TapsBit-e

rror

ratio

2 Loops (120km)

5 Loops (300km)

8 Loops (480km)

-120 -80 -40 0 40 80 120-60

-40

-20

0

Tap Number

Magnitude [

dB]

2 Loops (120km)

5 Loops (300km)

8 Loops (480km)

OVERVIEW

Introduction

Field demonstration of MDM upgrade scenarios

Conclusions and remarks

Hollow-core PBGF

FMF experiments

HC-PBGF EXPERIMENTS

• Light propagates in air meaning:

– Ultra low nonlinearities (>103 reduction over SMF)

– Ultra low Rayleigh scattering and potential for ultra-low overall transmission loss

• Low-loss can only be provided when overlap between the optical field and the glass is small

• Hard to achieve in reality! -> still actively being researched

– Ultimate low latency (99.7% the speed of light in vacuum)

HC-PBGF EXPERIMENTS (SINGLE-MODE)

• Highest capacity transmitted using coherent technology 24 Tb/s

– V.A.J.M. Sleiffer et al., “30.7 Tb/s (96 × 320 Gb/s) DP-32QAM transmission over 19-cell photonic band gap fiber”, Proc. OFC, OW1I.5 (2013)

• Longest distance transmitted using coherent technology and a re-circulating loop consisting of 6.2 km HC-PBGF -> 74.8 km

– M. Kuschnerov et al., “Data Transmission through up to 74.8 km of Hollow-Core Fiber with Coherent and Direct-Detect Transceivers”, Submitted to ECOC 2015

Interesting research topic!

HC-PBGF EXPERIMENTS (FEW-MODE)

V.A.J.M. Sleiffer et al., “High capacity mode-division multiplexed transmission in a novel 37-cell hollow-core photonic bandgap fiber”, Journal of Lightwave Technology 32 (4), p. 854-863 (2014)

HC-PBGF EXPERIMENTS (FEW-MODE)

• Total 73.7 Tb/s (96 × 3 × 256) over 310 m of 37-cell HC-PBGF

• Net datarate 57.6 Tb/s (taking into account FEC-overhead+Network protocols)

96 WDM channels

FEC-limit

V.A.J.M. Sleiffer et al., “High capacity mode-division multiplexed transmission in a novel 37-cell hollow-core photonic bandgap fiber”, Journal of Lightwave Technology 32 (4), p. 854-863 (2014)

-300 -200 -100 0 100 200 300-60

-40

-20

0

-300 -200 -100 0 100 200 300-60

-40

-20

0

4-5

ps/

m

12

-13

ps/

m

9-1

2 p

s/m

LP01 LP11 LP21 LP02

Tap Number

Mag

nit

ud

e [d

B]

Mag

nit

ud

e [d

B]

HC-PBGF EXPERIMENTS (FEW-MODE)

• Large DGD between modes

– Factor ~100 more than solid-core FMF

• (Not shown) Very large mode-dependent loss (MDL) of ~3-4 dB/km

LP01 LP01

LP11 LP11

V.A.J.M. Sleiffer et al., “High capacity mode-division multiplexed transmission in a novel 37-cell hollow-core photonic bandgap fiber”, Journal of Lightwave Technology 32 (4), p. 854-863 (2014)

Field demonstration of MDM upgrade scenarios

OVERVIEW

Introduction

Conclusions and remarks

FMF experiments

HC-PBGF

FIELD DEMONSTRATION OF MDM UPGRADE SCENARIO ON LEGACY NETWORKS

• All few-mode fiber work beside this is confined to laboratories

• Need to show backward compatibility of SDM technology with single mode technology

– No end-to-end FMF link immediately available

– Congested spans to be replaced first

FM-EDFA

FMF

MU

X

DE

MU

X

nxSSMF

m×ROADM Terminal

Terminal

Single-mode

Amplifiers

m×ROADM

n×SSMF

nxSSMF

n×SSMF

n×SSMF

n×SSMF

m×ROADM m×ROADM

V.A.J.M. Sleiffer et al., “Field demonstration of mode-division multiplexing upgrade scenarios on commercial networks”, Optics Express 21 (25), p. 31036-31046 (2013)

DETAILED TRIAL LAY-OUT

1,2) Flexi-rate prototypes A) Live A1 Network (1,023 km)

3) Commercial 100G B) Dark A1 fiber (52.2 km)

4) Offline receiver FMF) Few-mode fiber

Legend:

V.A.J.M. Sleiffer et al., “Field demonstration of mode-division multiplexing upgrade scenarios on commercial networks”, Optics Express 21 (25), p. 31036-31046 (2013)

DAC

EVEN

1

2

Salzb

urg

Klagenfurt

Bischofs-hofen

a

Vienna

Bb

Lin

k 3

Link 2

Link 1

1x4

DAC

ODD800

Symbols

1854 Sym.

5535 Sym.

8x8x1x8

1x8

193.95THz

193.95THz

100G

100G

optional

optionalW

SS

1

1

2

or

b

4

3

100G

Scope 1

Scope 2

Scope 3

Offlin

e D

SP

LO

LO

LO

CoherentRx 1

CoherentRx 2

CoherentRx 3

1x4

2

Salzb

urg

Bischofs-hofen

60km 60kmFMF FMF

FM-EDFA

Mode DEMUX

Mode MUX

b4

or

3

SCENARIO 1: SINGLE-MODE TRANSMISSION OVER FMF

V.A.J.M. Sleiffer et al., “Field demonstration of mode-division multiplexing upgrade scenarios on commercial networks”, Optics Express 21 (25), p. 31036-31046 (2013)

SCENARIO 1: SINGLE-MODE TRANSMISSION OVER FMF

• Transmission over 1,247 km (1,023 km live network) with three fiber types (SSMF, NZDSF, FMF)

• Coriant 100G-HD commercial cards used

V.A.J.M. Sleiffer et al., “Field demonstration of mode-division multiplexing upgrade scenarios on commercial networks”, Optics Express 21 (25), p. 31036-31046 (2013)

DAC

EVEN

1

260km 60kmFMF FMF

FM-EDFA

Mode DEMUX

Salzb

urg

Klagenfurt

Bischofs-hofen

a

Vienna

Bb

Lin

k 3

Link 2

Link 1

Mode MUX

1x4

DAC

ODD800

Symbols

1854 Sym.

5535 Sym.

8x8x1x8

1x8

193.95THz

193.95THz

100G

100G

optional

optional

WSS

1

1

2

or

b b

4

100G

Scope 1

Scope 2

Scope 3

Offlin

e D

SP

LO

LO

LO

CoherentRx 1

CoherentRx 2

CoherentRx 3

1x4

2

Salzb

urg

Bischofs-hofen

4

or

3

3

SCENARIO 1: SINGLE-MODE TRANSMISSION OVER FMF

• Most penalty from additional EDFAs

• Minimal penalty due to few-mode fibers (FMF)

• 100G commercial card was running for hours without post-FEC errors

V.A.J.M. Sleiffer et al., “Field demonstration of mode-division multiplexing upgrade scenarios on commercial networks”, Optics Express 21 (25), p. 31036-31046 (2013)

-4 -2 0 2 4 6 8 1010

-3

10-2

PLaunch

[dBm]

16 18 20 22

Bit-e

rror

ratio

Pump power [dBm]

0 60 120 18010

-4

10-3

10-2

Time [s]

Bit-e

rror

ratio

1,247 km (Link 1 to 3 + 120 FMF )

1,023 km (Link 1 & 2)

100G Performance over

SCENARIO 2: MID-LINK MODE MULTIPLEXING AND DE-MULTIPLEXING OF THREE SIGNALS

V.A.J.M. Sleiffer et al., “Field demonstration of mode-division multiplexing upgrade scenarios on commercial networks”, Optics Express 21 (25), p. 31036-31046 (2013)

SCENARIO 2: MID-LINK MODE MULTIPLEXING AND DE-MULTIPLEXING OF THREE SIGNALS

• Three single-mode signals transmitted over 52 km SMF and multiplexed onto FMF, de-multiplexed and transmitted again over three separate SMFs before detection and offline 6 × 6 MIMO-DSP

• Each fiber carrying either 16 WDM channels with 192-Gb/s DP-8QAM (total 7.2 Tb/s) or 256-Gb/s DP-16QAM modulation (total 9.6 Tb/s)

V.A.J.M. Sleiffer et al., “Field demonstration of mode-division multiplexing upgrade scenarios on commercial networks”, Optics Express 21 (25), p. 31036-31046 (2013)

60km 60kmFMF FMF

FM-EDFA

Mode DEMUX

Mode MUX

b4

or

3

DAC

EVEN

1

2

Salzb

urg

Klagenfurt

Bischofs-hofen

a

Vienna

Bb

Lin

k 3

Link 2

Link 1

1x4

DAC

ODD800

Symbols

1854 Sym.

5535 Sym.

8x8x1x8

1x8

193.95THz

193.95THz

100G

100G

optional

optionalW

SS

1

1

2

or

b

4

3

100G

Scope 1

Scope 2

Scope 3

Offlin

e D

SP

LO

LO

LO

CoherentRx 1

CoherentRx 2

CoherentRx 3

1x4

2

Salzb

urg

Bischofs-hofen

SCENARIO 2: MID-LINK MODE MULTIPLEXING AND DE-MULTIPLEXING OF THREE SIGNALS

• Good performance over 224 km combined FMF and SMF

V.A.J.M. Sleiffer et al., “Field demonstration of mode-division multiplexing upgrade scenarios on commercial networks”, Optics Express 21 (25), p. 31036-31046 (2013)

193.4 193.6 193.8 194 194.2 194.410

-7

10-6

10-5

10-4

10-3

10-2

Frequency [THz]

Bit-e

rror

ratio

-30

-25

-20

-15

-10

-5

-0

Rela

tive p

ow

er

[dB]

3·256-Gb/s DP-16QAM Avg. BER

3·192-Gb/s DP-8QAM Avg. BER

DP-sig. 1 DP-sig. 2 DP-sig. 3

Pol. X

Pol. Y

Pol. X

Pol. Y

sig. 1 sig. 2 sig. 3

SCENARIO 3: MULTI-RATE, MULTI-DISTANCE TRANSMISSION

V.A.J.M. Sleiffer et al., “Field demonstration of mode-division multiplexing upgrade scenarios on commercial networks”, Optics Express 21 (25), p. 31036-31046 (2013)

SCENARIO 3: MULTI-RATE, MULTI-DISTANCE TRANSMISSION

• 1 x 128 Gb/s DP-QPSK, 2 x 192 Gb/s DP-8QAM, different transmitters (lasers) running at the same wavelength

– Hybrid transmission in operation with live network

– 128-Gb/s DP-QPSK over 1,245 km, 192-Gb/s DP-8QAM over 224 km

V.A.J.M. Sleiffer et al., “Field demonstration of mode-division multiplexing upgrade scenarios on commercial networks”, Optics Express 21 (25), p. 31036-31046 (2013)

60km 60kmFMF FMF

FM-EDFA

Mode DEMUX

b4

or

3

DAC

EVEN

1

2

Salzb

urg

Klagenfurt

Bischofs-hofen

a

Vienna

Bb

Lin

k 3

Link 2

Link 1

1x4

DAC

ODD800

Symbols

1854 Sym.

5535 Sym.

8x8x1x8

1x8

193.95THz

193.95THz

100G

100G

optional

optional

WSS

1

1

2

or

b

4

3

100G

Scope 1

Scope 2

Scope 3

Offlin

e D

SP

LO

LO

LO

CoherentRx 1

CoherentRx 2

CoherentRx 3

1x4

Salzb

urg

Bischofs-hofen

2

Mode MUX

SCENARIO 3: MULTI-RATE, MULTI-DISTANCE TRANSMISSION

V.A.J.M. Sleiffer et al., “Field demonstration of mode-division multiplexing upgrade scenarios on commercial networks”, Optics Express 21 (25), p. 31036-31046 (2013)

0 2 4 6 8 1010

-7

10-6

10-5

10-4

10-3

10-2

Time [Min]

Bit-e

rror

ratio

Pol. X. Pol. Y.

192-Gb/s DP-8QAM 224 km:sig. 3sig. 2

128-Gb/s DP-QPSK 1,247 km sig. 1

FIELD DEMONSTRATION OF MDM UPGRADE SCENARIO ON LEGACY NETWORKS

We have successfully shown three possible upgrade scenarios for legacy networks with Space-Division-Multiplexing technology:

• Single-mode transmission over few-mode fiber with commercial 100G

– 1,127km single-mode fiber and 120 km few-mode fiber + few-mode EDFA

• 3 × SMF multiplexed onto FMF, de-multiplexed onto 3 × SMF again

– 3 mode-division multiplexed × 16 WDM × 192-Gb/s DP-8QAM (7.2 Tbit/s)

– 3 mode-division multiplexed × 16 WDM × 256-Gb/s DP-16QAM (9.6 Tbit/s)

• Multi-rate (QPSK, 8QAM), multi-distance (1,247 km and 224 km) transmission over 3 modes

– Different transmitter lasers

V.A.J.M. Sleiffer et al., “Field demonstration of mode-division multiplexing upgrade scenarios on commercial networks”, Optics Express 21 (25), p. 31036-31046 (2013)

Conclusions and remarks

OVERVIEW

Introduction

FMF experiments

HC-PBGF

Field demonstration of MDM upgrade scenarios

REMARKS ON COST AND ENERGY

• MIMO-DSP

– number of modes

– modal DGD

• Maybe able to minimize complexity by re-using information which affect all modes (carrier recovery/chromatic dispersion)

• FM-EDFA technology

– Higher energy efficiency?

– Cladding/core pumped?

• Coupled core fiber

– Minimize DGD

– Increase effective area

• Other network elements? ROADMs

M. Kuschnerov et al., “Energy efficient digital signal processing,” in Proc. OFC, paper Th3E.7 (2014).

Typical power dissipation distribution of the

different DSP processes in a 100-Gb/s DP-

QPSK line card

SD-FEC decoder

CD compensation

Other DSP modules

Carrier recovery

MIMO equalizer

CONCLUSIONS

• FMF/HC-PBGF is a potential transmission medium to increase the capacity per fiber system:

– Potential for capacity upgrade per fiber (57.6 Tb/s over FMF and PBGF)

– Long-haul reach achieved (1020 km over FMF)

– Interoperability with single-mode fiber technology demonstrated

• Important step to technology acceptance by telecom operators

• A lot of system tests still required, for instance to assess the fiber nonlinearity of FMFs

• Thesis available online: Towards petabit per second optical long-haul transmission links using space-division multiplexing technology

YACHT MAAKT WENDBAAR

THANK YOU FOR YOUR ATTENTION