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
BFRkT
BIRPe
PRISNR
NL
Drec
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
BFRkT
BIRPFeM
PRMISNR
NL
DinA
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
r
rPQ
1
120
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
BTB
10dB 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
BTB
BTB ER 10 dB
Inclusion of Amplifier
Build 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
1
120
21
AVEPQ
transmitter 1310nm
VOA1SOA
VOA2
20 nmfilter
receiver 1310nm
insertion loss α
Significant ASE levels
0v
APD based Receiver
Assumptions– -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 filter
20 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 P
ower
, dB
m (
BE
R10
e-10
)
0
1
2
3
4
5
6
7
8
9
10
Ext
inct
ion
Ra
tio, d
B
Prec pin
Prec APD
pin ext dB
APD ext dB
Post Amplifier Losses
Position amplifier to compensate for splitting and reach lossesSOA Psat limited to +13 dBmGain adjusted accordingly max
max
1G
GPG
Gin
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 35
Loss into Amplifier, dB
Lo
ss
aft
er
am
plif
ier,
dB
0
1
2
3
4
5
6
7
8
9
10
Ex
tin
cti
on
Ra
tio
, Po
we
r p
en
alt
y, d
B
Post Amplifier Loss
Unamplified Signal
Ppenalty
ext 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
Ma
rgin
Enh
anc
emen
t, d
B
128 split
-20
0
20
40
60
80
100
1 10 100 1000 10000
SplitRatio
Bac
khau
l Dis
tanc
e, k
m
Amplified Reach
Unamplified Signal
64 split128 split
32 Split64 Split512 Split
Psat limited
Gain 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 P
ower
, dB
m (
BE
R10
e-10
)
0
1
2
3
4
5
6
7
8
9
Ext
inct
ion
Ra
tio, 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
Po
wer
at
Rec
eive
r, d
Bm
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.