Reach extension of passive optical networks using semiconductor optical

amplifiersA E Kelly, C. Michie, I. Andonovic, J. McGeough, S

Kariaganopoulos

Standard Passive Optical Networks

GPON 1:32Reach 10-20km

Extended Reach Passive Optical Networks

Electronic regeneration cannot be used as it results in Preamble erosion due to burst mode locking time

Passive Optical Networks 1300nm backhaul

transmitter 1310nm

VOA1 SOA VOA2

20 nmfilter

receiver 1310nm

•VOA1 represents access loss – split plus some link loss•VOA2 predominately trunk loss•1300 nm and 1.25/2.5 Gbit/s; dispersion neglected

insertion loss α

Significant ASE levels

Power BudgetSimple linear model

2

22

tot

inPRSNR

PinPIN or APD

.)(4)(2

22

2

2

BFRkTBIRPe

PRISNRN

LDrec

in

TOT

P

shot noise terms thermal noise

receiver Noise Figure

pin

Power BudgetSimple linear model 2

22

tot

inPRSNR

PinPIN or APD

shot noise termsthermal noise

receiver Noise Figure

APD

BFRkTBIRPFeM

PRMISNRN

LDinA

in

TOT

P

)(4)(2 2

222

2

2

APD Multiplication and Noise Factor

SNR modified to account for ER of transmitter – at best 10 dB

Power Budget

e

eAVE

rrP

Q11

20

21

Baseline calculations

APDNeo PhotonicsPTB3J88-5638T-SC/PC+

pin – OCP- TRXAG1M

data modelled for commercial pin/APD

1.E-11

1.E-10

1.E-09

1.E-08

1.E-07

1.E-06

1.E-05

-30.00 -28.00 -26.00 -24.00 -22.00 -20.00

Receiver Power, dBm

BE

R

BTB10dB ER

1.E-11

1.E-10

1.E-09

1.E-08

1.E-07

1.E-06-36.00 -34.00 -32.00 -30.00 -28.00 -26.00

Receiver Power, dBm

BE

R

BTBBTB ER 10 dB

Inclusion of AmplifierBuild upon a model of the SNR to include the noise terms

associated with amplifier

2222221 ASEASEASESASEST

22220 ASEASEASET

Extinction Ratio further degraded due to ASE

ASEASE PPP /)( 1

11

20

21

AVEPQ

transmitter 1310nm

VOA1 SOA VOA2

20 nmfilter

receiver 1310nm

insertion loss α

Significant ASE levels

0v

APD based ReceiverAssumptions

– -28 dBm sensitivity for BTB un amplified with 10 dB ER– M=10– thermal noise estimated to give sensitivity of -28dBm

for 10-10 BER (value specified on data sheets)– Psat of SOA +13 dBm– NF 7 dB

Amplified APD Receiver

1.E-13

1.E-12

1.E-11

1.E-10

1.E-09

1.E-08

1.E-07

1.E-06

1.E-05

1.E-04

1.E-03

-45.00 -40.00 -35.00 -30.00 -25.00

Signal Power, dBm

BE

R

BTB infinite ERBTB 10 dB ER0.8 nm filter10 nm filter20 nm filter20 nm no ER deg

Baseline0.8nm filter10 nm filter20 nm filter

20 nm filterER not considered

Influence of Optical Filtering

-40.00

-39.00

-38.00

-37.00

-36.00

-35.00

-34.00

-33.00

-32.00

-31.00

-30.00

0 5 10 15 20

Optical Filter Bandwidth, nm

Rec

eive

r Pow

er, d

Bm

( B

ER

10e-

10)

0

1

2

3

4

5

6

7

8

9

10

Ext

inct

ion

Rat

io, d

B

Prec pinPrec APDpin ext dBAPD ext dB

Post Amplifier Losses

Position amplifier to compensate for splitting and reach lossesSOA Psat limited to +13 dBmGain adjusted accordingly max

max

1GGP

GG

in

Splitter(Access)

lossSOA Backhaul

20 nmfilter

OLTreceiver 1310nm

insertion loss αONT

System Power Margins

0

5

10

15

20

25

30

35

40

0 5 10 15 20 25 30 35Loss into Amplifier, dB

Loss

afte

r am

plifi

er, d

B

0

1

2

3

4

5

6

7

8

9

10

Extin

ctio

n R

atio

, Pow

er p

enal

ty, d

B

Post Amplifier LossUnamplified SignalPpenaltyext dB

pre-amp margin

booster margin

mid span margin benefit

GPON

Margin Enhancement for Amplified GPON

0

5

10

15

20

25

30

0 5 10 15 20 25 30 35 40

Loss into Amplifier, dB

Sys

tem

Mar

gin

Enh

ance

men

t, dB

128 split

-20

0

20

40

60

80

100

1 10 100 1000 10000

SplitRatio

Bac

khau

l Dis

tanc

e, k

m

Amplified ReachUnamplified Signal

64 split128 split

32 Split64 Split512 Split

Psat limitedGain limited

NF limitedGPON: 32 split

Distance versus number of users for each case

Experiment

VOA SOA VOAl

Channel DropOSA

(filter)

1300 nmreceiver

1300 tx

Experimental Validation

1.E-10

1.E-09

1.E-08

1.E-07

1.E-06

1.E-05

-40.00 -38.00 -36.00 -34.00 -32.00 -30.00 -28.00 -26.00

Signal Power, dBm

BE

R

BTB Theory10 nm theory20 nm theory20nmBTB10 nm

Constant BER curve with filter width

-40

-39

-38

-37

-36

-35

-34

-33

-32

-31

-30

0 5 10 15 20

Optical Filter Bandwidth, nm

Rec

eive

r Pow

er, d

Bm

( B

ER

10e-

10)

0

1

2

3

4

5

6

7

8

9

Ext

inct

ion

Rat

io, d

B

Prec APD

Sens

APD ext dB

Experimental Margin Enhancement

-30

-20

-10

0

10

20

30

40

50

60

0 5 10 15 20 25 30 35

Loss into Amplifier, dB

Pos

t Am

plifi

er M

argi

n, d

B

-35

-30

-25

-20

-15

-10

-5

0

Pow

er a

t Rec

eive

r, dB

m

Loss Post Amp TheoryLoss Post Amp ExptUnamplifiedP BER10-9 EXPTP 10-9 theory

Conclusions• Number of users and backhaul distance can be

considerably increased by using SOA based amplification• Required SOA specification depends on placement within

network• A single SOA cannot meet these requirements • Variable gain clamping schemes?

Key PublicationsRussell P. Davey, Daniel B. Grossman, Michael Rasztovits-Wiech, David B. Payne, Derek Nesset, A. E. Kelly, Albert Rafel, Shamil Appathurai, and Sheng-Hui Yang “Long-Reach Passive Optical Networks” Journal of Lightwave Technology, Vol. 27, Issue 3, pp. 273-291 February 2009 (invited tutorial paper)High Performance Semiconductor Optical Amplifier Modules at 1300nm”A.E.Kelly, C.Michie, I.Armstrong, I.Andonovic, C. Tombling, J.McGeough and B.C.Thomsen, Photon.Tech.Lett, Vol.18, No.24, pp 2674-2676, 2006“The Dynamic Gain Modulation Performance of Adjustable Gain-Clamped Semiconductor Optical Amplifiers (AGC-SOA)” Liu, L. Michie, C. Kelly, A. E. Andonovic, I., Journal of Lightwave Technology , Volume: 29 Issue: 22 pp 3483 – 3489, 2011.