100 Tbit/s spectral-efficient Data Link Using Orbital Angular Momentum Multiplexing
H. Huang, G. Xie, Y. Yan, N. Ahmd, Y. Ren and A. E. Willner Optical Communication Lab, Ming Hsheh Department of Electrical Engineering, University of Southern Califoria
[email protected], supported by Darpa Inpho program
Problem: Bandwidth demand > Spectral resource Existing Solutions
λ1 λ2 λ3
Freq.
WDM on multiple OAM modes
Data 1
Data 2
Data 3
Gaussian
Gaussian
Gaussian Gaussian
Data 123
Data 456
Data 789
Data 123
λ1
λ2
λ3
l1 l2 l3 OAM modes
OAM Phase
Transmitter array
Wavelength multiplexing
Convert Gaussian mode to OAM mode
OAM mode multiplexing
Receiver array Wavelength demultiplexing
Convert OAM mode to Gaussian mode
OAM mode demultiplexing
Propagation
Experimental results
0 100 200 300 400 50087654321
Channel Number
-log1
0(BE
R)
EFEC threshod
10
15
20
25
30
35
40
OSNR (dB)
500 600 700 800 900 100087654321
Channel Number
-log1
0(BE
R)
EFEC threshod
10
15
20
25
30
35
40
OSNR (dB)
BER
OSNR
BER
OSNR
FEC threshold FEC threshold
squeeze the channel spacing
Freq.
Freq.
Ch1 Ch2 Ch3
Ch1 Ch2 Ch3
Spectral resource is limited, even for optics.
(Tbit/s)
Loss
(dB
/km
)
Utilize advanced modulation formats
>60 Tbit/s capacity is needed by 2015.
Year
1 bit/symbol 2 bit/symbol 4 bit/symbol
Spectral efficiency is improved by 4 times, but we need more.
OAM l1
OAM l2
OAM l3
OAM l4
Multiplexing
SuperImposed OAMs
OAM l1
OAM l3
OAM l4 Data 1
Data 3
Data 2
Data 4 OAM l2
Intensity
Intensity
Data 1
Data 2
Data 3
Data 4
Demultiplexing
-4 -3 -2 -1 0 1 2 3
x 10-3
-4
-3
-2
-1
0
1
2
3
x 10-3
l = 0
(OAM = +1)
-4 -3 -2 -1 0 1 2 3
x 10-3
-4
-3
-2
-1
0
1
2
3
x 10-3
0100
200
300
400
500
600
0
0.5 1
1.5 2
2.5 3
x 1
05
0100
200
300
400
500
600
0 2 4 6 8
10
12
x 1
04
Non-OAM beam
-2
0
2
-2
0
2
OAM beam
Phase front Intensity profile
“Pasta spirals” Phase “Donut” Intensity
What is OAM How to generate OAM
Phase
OAM multiplexing/demultiplexing
Know
about OA
M
How to detect OAM
OAM is a new degree of freedom to improve the spectral efficiency and capacity
3 modes 6 modes 12 modes 24 modes
42 wavelengths
24 OAM modes
1008 independent channels
100 Gbit/s QPSK on each
channel
Spectral efficiency ×24
Total capaicty 100.8 Tbit/s
Achievements
Hao Huang et al., OFC2013, paper OTh4G.5