Itsuro Morita

Transcription

Itsuro Morita

High capacity transmission over transoceanic
distances with space-division-multiplexing
Itsuro Morita
KDDI R&D Laboratories Inc.,
October 21, 2013
1
Upcoming capacity crunch
October 21, 2013
2
Remaining orthogonal dimensions
Space Division Multiplexing
Time
e.g. 10 Gbit/s
Frequency
(Wavelength)
100 Gbit/s
Time
Frequency
e.g. 50 GHz space
Symbol rate space
imaginary
QAM
cos()
sin()
Polarization
real
QPSK
256QAM
16QAM
y
Single Pol.
Dual Pol.
x
Space
Core
Space
Mode
October 21, 2013
single core
LP01
LP11a
multiple cores
LP11b
LP21a
LP21b
LP02
LP31a
LP31b
3
Optical fibers for SDM
Single-Core Fiber
(SCF)
Multi-Core Fiber (MCF)
Uncoupled MCF
Coupled MCF
Single-Mode
(SM)
Few-Mode
(FM)
Multi-Mode
(MM)
October 21, 2013
4
MCF transmission experiments over 1000km
Fiber
7-core
MCF
3-core
MCF
7-core
MCF
7-core
MCF
7-core
MCF
12-core
MCF
Amplifier
Net bitrate Distance
CDP
[bit/s/fiber] [km] [Ebit/s·km]
SC- EDFA
7.5T
2,688
0.020
ECOC2011 [7]
SC- EDFA
1.0T
4,200
0.004
OFC2012 [8]
MC-EDFA
28.8T
6,160
0.177
ECOC2012 [9]
MC-EDFA
110.9T
6,370
0.706
2013 [10]
MC-EDFA
140.7T
7,326
1.03
ECOC2013 [5]
MC-EDFA
+Raman
688T
1,500
1.03
ECOC2013 [6]
CDP: Capacity distance product
MCF: Multi-core (MC) fiber
SC-EDFA: Single-core EDFA, MC-EDFA: Multicore EDFA
October 21, 2013
Year
OPTICSEXPRESS
Trans-oceanic class MCF transmission
 Demonstration of trans-oceanic class space-division-multiplexing (SDM)
transmission with MC-EDFA
 40 x 128 Gbit/s transmission per core over 6,160km 7-core MCF
- Total capacity : 28.8 Tbit/s per fiber
- CDP : 177 Pbit/s･km
 264 x 72 Gbit/s transmission per core over 6,370 km 7-core MCF
- Total capacity : 111 Tbit/s per fiber
- CDP : 1.03 Ebit/s･km
October 21, 2013
6
October 21, 2013
7
7-core MCF
Cross-section of MCF
Core #1 is center core
Parameter
Value
# of cores
7
Cladding diameter
200 μm
Core pitch
56 μm
Effective area (Aeff)
99 μm2
Attenuation loss
0.188-0.200 dB/km
Chromatic dispersion
18.4-18.7 ps/nm/km
Span length
55 km
Total span loss
incl. Fan-in/Fan-out
11.4 to 12.3 dB
Thin Fibers
MCF
Fiber Bundle
Fan-in/Fan-out
October 21, 2013
End face of fiber bundle
8
7-core MC-EDFA
Cross-section of 7-core
MC-EDF[1]
Parameter
Value
# of cores
7
Cladding diameter
180 μm
Core pitch
45 μm
Attenuation loss
~3.4 dB/m
Gain
15 dB
NF (typ.) incl. loss of Fan-in/out, WDM cpl.
7 dB
Configuration
[1] Y. Tsuchida et al, ECOC2012, Tu4F2.
October 21, 2013
Gain and noise figure (NF)
9
Crosstalk(XT) of MC-EDFA and MCF
XT of MC-EDFA (between 2 cores)
XT of MCF (between 2 cores)
Core #1 is center core
 Total XT of MC-EDFA at center core: < -46.5 dB (worst)
 Total XT of MCF at center core :
< -45.6 dB per span (worst)
 Total XT per span at center core : < -43 dB per span (worst)
e.g. Accumulated XT after 6,160 km transmission with 112 spans: < -22.5 dB
October 21, 2013
10
Experimental setup
RX
TX
Odd ch.
ECL
…
AWGr
Ch1
Ch3
Ch40
AWGr
…
Ch39
DFB, ECL
Ch2
Ch4
Delay
DATA
I
IQM
Q
DATA
32 Gb/s PPG
55 km MCF
Q
ADC
Core#1 in
3dB PBC
100‐50G IL
Even ch.
ECL: External cavity laser
AWGr: Arrayed waveguide grating
IQM: IQ modulator
PME: Polarization multiplexing emulator
PBC: Polarization beam combiner
GFF: Gain flatting filter
Balanced
PDs
ADC
PME
Delay
Delay
I
IQM
MC-EDFA
Integrated pol.
Optical signal ‐diverse hybrid
SW
GFF
#2 in
GFF
#3 in
GFF
#4 in
GFF
#5 in
GFF
#6 in
#7 in
LO
ADC
ADC
Real‐time oscilloscope
LO: Local oscillator ~100 kHz LW
Balanced PD: Photo diodes
ADC: Analog/digital converter
(50 GSa/s, 16 GHz bandwidth)
GFF
 40 x 128-Gbit/s PDM-QPSK signals (SD-FEC with 20% OH)
 Received signal is processed offline
 7 cores are connected sequentially using fan-in/fan-out[2]
[2]S. Chandrasekhar et al, ECOC2011, Th13C4.
October 21, 2013
11
Transmission performance
 Q-factor vs Transmission distance
 The Q-penalty after transmission is about 1.4 dB
 The impact of XT is low even after 6,160 km transmission of MCF with
more than 100 MC-EDFAs
October 21, 2013
12
 After 6,160 km transmission
1550.116 nm
1558.173 nm
1565.905 nm
FEC limit = 6.4 dB
 All of channels surpassed FEC limit [1] with Q-margin of 1 dB
 Total capacity : 7-core x 40ch x 103.125 Gbit/s(net) = 28.8 Tbit/s per fiber
 CDP :177 Pbit/s x km
October 21, 2013
13
October 21, 2013
14
Experimental setup
SW7
AWG
RX
Real-time
oscilloscope
BPD
BPD
BPD
BPD
Pol.-diversity
optical hybrid
GFF
GFF
GFF
MC-EDFA
core1
core2
7:1 switch
SW
SW2
PME

1x8 splitter
8 lasers
IQM
37.5GHz space

Odd 24GS/s D
AWG

D
Even
8 lasers
IQM
37.5GHz space
Loading
132 lasers
IQM
IQM
37.5GHz space

18.75GHz
24GS/s
SW1
TX
core7
46 km MCF
OBPF
ECL
7 x 264 channel x 72 Gbit/s (111 Tbit/s) quasi-Nyquist-WDM PDM-QPSK
signal transmission over 6,370 km
October 21, 2013
15
Quasi-Nyquist-WDM PDM-QPSK signal
Single channel
WDM
10-1
BER
Power [10dB/div]
18GHz
WDM
Single Channel
10-2
10-3
10-4
10-5
10-6
5
-20
-10
0
10
20
10
15
20
OSNR (noise in 0.1 nm) [dB]
Frequency [GHz]
Bit rate : 128 Gbit/s → 72 Gbit/s
Spectral Efficiency : 2 bit/s/Hz → 3.2 bit/s/Hz
October 21, 2013
16
7-core MCF
2
7
1
3
6
4
5
trench index core profile
0.4
 [%]
0.2
0
-0.2
-0.4
-0.6
-0.8
-20 -10
Parameter
Value
# of cores
7
Cladding diameter
196 μm
Core pitch
56 μm
Effective area (Aeff)
99 → 121 μm2
Attenuation loss
0.196-0.200 dB/km
Chromatic dispersion
18.4-18.7 ps/nm/km
Span length
55 → 45.5 km
Total span loss
incl. Fan-in/Fan-out
11.4 - 12.3 dB
→ 9.9 – 10.5 dB
0 10 20
r [µm]
October 21, 2013
17
1-2
1-3
1-4
1-5
1-6
1-7
2-1
2-3
2-4
2-5
2-6
2-7
3-1
3-2
3-4
3-5
3-6
3-7
4-1
4-2
4-3
4-5
4-6
4-7
5-1
5-2
5-3
5-4
5-6
5-7
6-1
6-2
6-3
6-4
6-5
6-7
7-1
7-2
7-3
7-4
7-5
7-6
Crosstalk [dB]
Crosstalk of MCF
October 21, 2013
-40 1550 nm
-50
-60
-70
-80
Pair of cores
 Total XT of MCF at center core per span : < -45.6 dB → -51 dB
18
7-core MC-EDFA
Single stage configuration
→ Two stage configuration for higher output power
- Bandwidth: 1.9 THz → 5 THz
25
Gain [dB]
20
15
10
NF [dB]
5
core1
core5
core2
core6
core3
core7
core4
0
7
6
5
NF<5.5dB
4
3
1530
October 21, 2013
1540 1550
Wavelength [nm]
1560
19
core2
core3
core5
core6
core7
core4
QQ値
factor
[dB]
[dB]
8
6
FEC threshold : 5.9 dB
4
2
191
192
193
194
195
光パワー
[10dB/div]
Optical
Power
[10dB/div]
core1
196
Frequency
[THz]
周波数 [THz]
Capacity-Distance Product : 707 [Pbit/s x km]
October 21, 2013
20
October 21, 2013
21
Experimental Setup
8 lasers
25GHz space
IQM
SW1
PC
WSS
WSS
Loading
MZM
12.5GHz
25GHz
IQM
SW
t
50GS/s
AWG
25GHz-spaced 201-WDM
100Gbit/s DP-QPSK
with duobinary-pulse shaping
(20%-overhead SD-FEC)
October 21, 2013
core2
GFF
core7
MC-EDFA 45.5km MCF
OBPF
BPD
30GBaud
Frequency
GFF
core1
PME
SW7
101 lasers
50GHz space
OSA
GFF
7:1 switch
t
D
SW2
Even
t
D
50GS/s
AWG
WSS
Power Splitter
Odd
IQM
PME
8 lasers
25GHz space
Real-time
oscilloscope
BPD
BPD
BPD
Pol.-diversity
optical hybrid
ECL
7 x 201 channel x 100 Gbit/s (140.7 Tbit/s) superNyquist-WDM signal transmission over 7,326 km 22
Duobinary-Pulse Shaping and
Maximum-Likelihood Sequence Estimation
IQ map
Q factor
2-3dB
Impulse response
Duobinarypulse shaping
DPQPSK
after duobinary
pulse shaping
MLSE
OSNR
sinc
function
delayed
sinc
function
Duobinary trellis
t=0
0
0/0
1/1
Time [1/baudrate/div]
1
t = 1/B
0/0
1/1
0/1
t = 2/B
0/0
t = 3/B
1/1
0/1
1/2
1/2
Proposed by J. Li et al., J. Lightwave Technol., 30, 1664 (2012) [13].
October 21, 2013
23
Back-to-Back Performance
Baudrate : 30GBaud
WDM spacing : 25GHz
Measured Bit-Error Rates
Optical spectra of signals
Spectral overlap
SC
10-1
Nyquist pulse shaping
SC WDM
Duobinary pulse shaping
SC WDM
WDM
Duobinary-pulse shaping
WDM
SC
Frequency [25GHz/div]
BER
Power [10dB/div]
Nyquist-pulse shaping
10-2
10-3
10-4
10-5
10-6
10-7
10
15 20 25
OSNR [dB]
Duobinary pulse shaping can suppress WDM crosstalk from adjacent channels.
The penalty is around 2 dB compared with single-channel DP-QPSK.
October 21, 2013
24
Transmission Performance
9
Q2 factor [dB]
8
core1
core4
core7
core2
core5
core3
core6
7
6
FEC threshold : 5.9 dB [14]
5
191
192
193
194
195
196
Frequency [THz]
Q2 factors for all 1,407 channels (201-WDM, 7-Core) > 6.0dB
Capacity-Distance Product : 1.03 [Exabit/s x km]
October 21, 2013
25
High-capacity transmission experiments
Distance [km]
Transmission Experiments over 10Tbit/s・1,000km
Single-core fiber
Multi-core fiber
10,000
5,000
2,000
1,000
10
October 21, 2013
100
1,000
Capacity per fiber [Tbit/s]
26
Power Consumption
Reduction of power consumption
Core pumped
MC-EDFA
October 21, 2013
Multiple-Pumps
Signals
Single Pump
Cladding pumped MC-EDFA
Signals
Core in MC-EDFA
Multiple cores pumped
by multimode LD
w/o temp. control
27
Summary
 Demonstration of trans-oceanic class space-divisionmultiplexing (SDM) transmission with MCF and MC-EDFA
 40 x 128 Gbit/s transmission over 6,160 km
- CDP : 1.03 Exabit/s･km
October 21, 2013
28
Thank you !!
The part of this work was supported by
“Research on Innovative Optical Fiber Technology” and
“R&D of Innovative Optical Communication Infrastructure”
The author thanks NEC Corporation and Furukawa Electric Co.,
Ltd. for their contributions.
October 21, 2013
29

Itsuro Morita

Transcription

Similar documents