Optical Interface for 100G SMF 10km...
Transcript of Optical Interface for 100G SMF 10km...
Optical Interface for 100G SMF 10km PMD
Matt TraversoMasato Shishikura
Kiyo Hiramoto
IEEE Interim Seoul, KoreaSeptember 2007
2
Supporters
• Masahiro Aoki, Hitachi Ltd.• Frank Chang, Vitesse• John Dallesasse, Emcore• Ali Ghiasi, Broadcom• Shinji Nishimura, Hitachi Ltd.• Hidehiro Toyoda, Hitachi Ltd.
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Agenda
• Next Steps to standardize SMF “short” reach PMD• Wavelength Spacing; CWDM vs. Narrow Spacing
(iWDM)• Wavelength Grid Impact on Chromatic Dispersion
Penalty– Modulation: EA type versus DM type– Reach Considerations
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Path to Move Forward
• Key Milestones for PMD Standardization– Approximate Distance and Media included in the PAR
• “Provide Physical Layer specifications which support 100 Gb/soperation over: … at least 10km on SMF”
– Outline in Brief• Select Lane width of optical interface• Select Wavelength(s) and Approximate Grid• Propose Optical Budget• Refine Distance Target & other parameters• Iterate Analysis and Refinements of PMD
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Reiterate Case for 4x25Gbit/s
• Lane rate of ~25Gbit/s scales well for future generations of IC technology
• From optics point of view simpler interconnect and packaging than 40Gbit/s– Intention is to leverage 10Gbit/s packaging and interconnect
technology
• Modulation of 25Gbit/s suitable for a direct modulation laser– Implementation of 25Gbit/s DML depends upon the final distance
objective
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CWDM vs. Narrow Spacing (iWDM)
• CWDM allows for use of uncooled lasers• iWDM requires use of a thermoelectric cooler (TEC) to maintain the
laser chip(s) at constant temperature– Likely that 4 individual TECs would be required for initial implementation
• CWDM spacing therefore will yield modules with lower power dissipation
CWDM Proposal for 10km PMD
Proposal for 40km PMD
2.2 nm Pitch
1nm Bandwidth
80 nm1361 nm1291 nm
63 nm1294.5 nm 1357.5 nm
8.8 nm
7.6 nmSimilar to iWDM proposal
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Power & Cost comparison; CWDM vs. iWDM
• CWDM module can achieve: – Lower cost than tighter wavelength spaced module– Considers the cost of the laser relative to the wavelength spread of the wafer
• Initially CWDM module will likely be similar in power consumption via wide-temperature semi-cooled EA-DFB
• In the future, as uncooled technology matures:– CWDM module can achieve ~ 2 W lower power consumption – Lower cost due to larger proportion of die in the acceptable wavelength region
LD typePower
consumption(W)
Realtive Cost(Wavelength
tolerance)LD type
Powerconsumption
(W)
Realtive Cost(Wavelength
tolerance)
1310nm CWDM CooledEA-DFB 6 1.0
(+/-6nm)Uncooled
DFB 1.60.8 to 1
(+/-1.1 to 2.6nm)
1310nm iWDM CooledEA-DFB 6 2.8
(+/-0.35nm)Cooled
DFB 3.3 2.8(+/-0.35nm)
First Generation Future
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CWDM(ITU-T) grid study for 10 km
Objective- Which CWDM(ITU) grid set is better, 1271-1331nm or 1291-1351nm ?- How much is chromatic dispersion penalty ?
Simulate the penalty of each CWDM grid setHypothesis- Bit rate: 25.8Gbps- Distance: 10 km- Without non-linear effect - TX tr/tf: 15ps(20-80%)- Waveform: Super-Gaussian (*1)
Parameter- α: -1~4 (EA:-1~1, DM:2~7) (*2)- Extinction ratio: 5~10dB
B2B, ER=7dB, λ0=1312nm, tr/tf=15ps
0
0.2
0.4
0.6
0.8
1
1.2
0 20 40 60 80
Time (ps)
Am
plit
ude
(ar
b. u
nit
)
B2B optical waveform
Note(*1): Does not simulate actual waveforms of EML and DM DFB-LD.Note(*2): alpha is set constant.
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Chromatic dispersion
Dispersion@10km,SSMF- 1271-1331nm: -59ps/nm(min), 33ps/nm(max), |DZ|=59ps/nm(max) - 1291-1351nm: -38ps/nm(min), 50ps/nm(max), |DZ|=50ps/nm(max)
Chromatic Dispersion
-8
-7
-6
-5
-4
-3
-2
-1
0
1
2
3
4
5
6
7
8
1251 1261 1271 1281 1291 1301 1311 1321 1331 1341 1351 1361 1371
Wavelength (nm)
Chro
mat
ic D
ispe
rsio
n (
ps/nm
/km
)
λ0(nm) min 1300 λ0(nm) center 1312 λ0(nm) max 1324
1271 1291 1311 1331 1351
1300
1312
1324
λ0=
-5 .94ps/nm/km
-3 .85ps/nm/km
5 .02ps/nm/km
3 .34ps/nm/km
Chromatic Dispersion 10km
-80
-70
-60
-50
-40
-30
-20
-10
0
10
20
30
40
50
60
70
80
1251 1261 1271 1281 1291 1301 1311 1321 1331 1341 1351 1361 1371
Wavelength (nm)
Chro
mat
ic D
ispe
rsio
n@
10km
(ps
/nm
)
λ0(nm) min 1300 λ0(nm) center 1312 λ0(nm) max 1324
1271 1291 1311 1331 1351
1300
1312
1324
λ0=
-59 .36ps/nm
-38 .46ps/nm
50 .17ps/nm
33 .44ps/nm
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EA-Mod: 10km CD Penalty
CWDM grid set (EA: -1<α<1)- 1291-1351nm grid set is better- CD penalty@10km: ~1dB
EA 10km(-1<α<1、Er=7dB)
-1
-0.5
0
0.5
1
1.5
2
1251 1271 1291 1311 1331 1351 1371
Wavelength (nm)
CD
penal
ty @
10km
(dB
)
α=-1(λ0=1324nm) α=1(λ0=1300nm)
1271 1291 1311 1331 1351
1.24dB
0.99dB
B2B, ER=7dB, λ0=1312nm, tr/tf=15ps
0
0.2
0.4
0.6
0.8
1
1.2
0 20 40 60 80
Time (ps)
Am
plit
ude
(ar
b. u
nit
)
α=-1, λ=1264.5nm, 10km, ER=7dB, λ0=1324nm,tr/tf=15ps
0
0.2
0.4
0.6
0.8
1
1.2
0 20 40 60 80
Time (ps)
Am
plit
ude
(ar
b. u
nit
)
α=1, λ=1337.5nm, 10km, ER=7dB, λ0=1300nm,tr/tf=15ps
0
0.2
0.4
0.6
0.8
1
1.2
0 20 40 60 80
Time (ps)
Am
plit
ude
(ar
b. u
nit
)
B2B
λ=1264.5nmpenalty=1.24dBα=-1λ0=1324nm
λ=1357.5nmpenalty=0.99dBα=1λ0=1300nm
0.25dB
α=1, λ0=1300nmα=-1, λ0=1324nm
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Direct Mod: 10km CD Penalty
CWDM grid set (DM: 2<α<4)- 1271-1331nm set is better- But penalty >>2dB - New lower chirping technologyis needed (α<2)
CD penalty @ 10km
0
1
2
3
4
5
6
7
8
9
10
-2 -1 0 1 2 3 4 5
alpha
CD
penal
ty @
10km
(dB
)
1271-1331 1291-1351
EA-DFB DM-DFB
α=2, λ=1337.5nm, 10km, ER=7dB, λ0=1300nm,tr/tf=15ps
0
0.2
0.4
0.6
0.8
1
1.2
0 20 40 60 80
Time (ps)
Am
plit
ude
(ar
b. u
nit
)
α=3, λ=1337.5nm, 10km, ER=7dB, λ0=1300nm,tr/tf=15ps
0
0.2
0.4
0.6
0.8
1
1.2
0 20 40 60 80
Time (ps)
Am
plit
ude
(ar
b. u
nit
)
α=4, λ=1337.5nm, 10km, ER=7dB, λ0=1300nm,tr/tf=15ps
0
0.2
0.4
0.6
0.8
1
1.2
0 20 40 60 80
Time (ps)
Am
plit
ude
(ar
b. u
nit
)
λ=1357.5nm(λ0=1300nm)
α=2
λ=1337.5nm(λ0=1300nm)
penalty=3.52dB
penalty=2.24dB
penalty=1.32dB
α=2, λ=1357.5nm, 10km, ER=7dB, λ0=1300nm,tr/tf=15ps
0
0.2
0.4
0.6
0.8
1
1.2
0 20 40 60 80
Time (ps)
Am
plit
ude
(ar
b. u
nit
)
penalty=2.33dB
α=3, λ=1357.5nm, 10km, ER=7dB, λ0=1300nm,tr/tf=15ps
0
0.2
0.4
0.6
0.8
1
1.2
0 20 40 60 80
Time (ps)
Am
plit
ude
(ar
b. u
nit
)
penalty=4.50dB
α=4, λ=1357.5nm, 10km, ER=7dB, λ0=1300nm,tr/tf=15ps
0
0.2
0.4
0.6
0.8
1
1.2
0 20 40 60 80
Time (ps)
Am
plit
ude
(ar
b. u
nit
)
penalty=9.52dB
α=3
α=4
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Direct Mod: 2km CD Penalty
CD penalty @ 2km (DM)
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
1 2 3 4 5
alpha
CD
penal
ty @
10km
(dB
)
1271-1331 1291-1351
DM: α>2
CWDM grid set - CD penalty is less than 1dB
each grid set (DM: 2<α<4)
λ=1357.5nm(λ0=1300nm)
α=2
λ=1337.5nm(λ0=1300nm)
α=3
α=4
α=4, λ=1357.5nm, 2km, ER=6dB, λ0=1300nm,tr/tf=15ps
0
0.2
0.4
0.6
0.8
1
1.2
0 20 40 60 80
Time (ps)
Am
plit
ude
(ar
b. u
nit
)
α=3, λ=1357.5nm, 2km, ER=6dB, λ0=1300nm,tr/tf=15ps
0
0.2
0.4
0.6
0.8
1
1.2
0 20 40 60 80
Time (ps)
Am
plit
ude
(ar
b. u
nit
)
α=4, λ=1337.5nm, 2km, ER=6dB, λ0=1300nm,tr/tf=15ps
0
0.2
0.4
0.6
0.8
1
1.2
0 20 40 60 80
Time (ps)
Am
plit
ude
(ar
b. u
nit
)
α=3, λ=1337.5nm, 2km, ER=6dB, λ0=1300nm,tr/tf=15ps
0
0.2
0.4
0.6
0.8
1
1.2
0 20 40 60 80
Time (ps)
Am
plit
ude
(ar
b. u
nit
)
α=2, λ=1357.5nm, 2km, ER=6dB, λ0=1300nm,tr/tf=15ps
0
0.2
0.4
0.6
0.8
1
1.2
0 20 40 60 80
Time (ps)
Am
plit
ude
(ar
b. u
nit
)
α=2, λ=1337.5nm, 2km, ER=6dB, λ0=1300nm,tr/tf=15ps
0
0.2
0.4
0.6
0.8
1
1.2
0 20 40 60 80
Time (ps)
Am
plit
ude
(ar
b. u
nit
)
penalty=0.43dBpenalty=0.68dB
penalty=0.32dBpenalty=0.49dB
penalty=0.21dBpenalty=0.32dB
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Direct Mod: 4km CD Penalty
λ=1357.5nm(λ0=1300nm)
λ=1337.5nm(λ0=1300nm)
α=1α=1, λ=1357.5nm, 4km, ER=6dB, λ0=1300nm,
tr/tf=15ps
0
0.2
0.4
0.6
0.8
1
1.2
0 20 40 60 80
Time (ps)
Am
plit
ude
(ar
b. u
nit
)
α=6, λ=1357.5nm, 4km, ER=6dB, λ0=1300nm,tr/tf=15ps
0
0.2
0.4
0.6
0.8
1
1.2
0 20 40 60 80
Time (ps)
Am
plit
ude
(ar
b. u
nit
)
α=5, λ=1357.5nm, 4km, ER=6dB, λ0=1300nm,tr/tf=15ps
0
0.2
0.4
0.6
0.8
1
1.2
0 20 40 60 80
Time (ps)
Am
plit
ude
(ar
b. u
nit
)
α=4, λ=1357.5nm, 4km, ER=6dB, λ0=1300nm,tr/tf=15ps
0
0.2
0.4
0.6
0.8
1
1.2
0 20 40 60 80
Time (ps)
Am
plit
ude
(ar
b. u
nit
)
α=3, λ=1357.5nm, 4km, ER=6dB, λ0=1300nm,tr/tf=15ps
0
0.2
0.4
0.6
0.8
1
1.2
0 20 40 60 80
Time (ps)
Am
plit
ude
(ar
b. u
nit
)
α=2, λ=1357.5nm, 4km, ER=6dB, λ0=1300nm,tr/tf=15ps
0
0.2
0.4
0.6
0.8
1
1.2
0 20 40 60 80
Time (ps)
Am
plit
ude
(ar
b. u
nit
)
α=2 α=3 α=4 α=5 α=6
α=1, λ=1337.5nm, 4km, ER=6dB, λ0=1300nm,tr/tf=15ps
0
0.2
0.4
0.6
0.8
1
1.2
0 20 40 60 80
Time (ps)
Am
plit
ude
(ar
b. u
nit
)
α=2, λ=1337.5nm, 4km, ER=6dB, λ0=1300nm,tr/tf=15ps
0
0.2
0.4
0.6
0.8
1
1.2
0 20 40 60 80
Time (ps)
Am
plit
ude
(ar
b. u
nit
)
α=3, λ=1337.5nm, 4km, ER=6dB, λ0=1300nm,tr/tf=15ps
0
0.2
0.4
0.6
0.8
1
1.2
0 20 40 60 80
Time (ps)
Am
plit
ude
(ar
b. u
nit
)
α=4, λ=1337.5nm, 4km, ER=6dB, λ0=1300nm,tr/tf=15ps
0
0.2
0.4
0.6
0.8
1
1.2
0 20 40 60 80
Time (ps)
Am
plit
ude
(ar
b. u
nit
)
α=5, λ=1337.5nm, 4km, ER=6dB, λ0=1300nm,tr/tf=15ps
0
0.2
0.4
0.6
0.8
1
1.2
0 20 40 60 80
Time (ps)
Am
plit
ude
(ar
b. u
nit
)
α=6, λ=1337.5nm, 4km, ER=6dB, λ0=1300nm,tr/tf=15ps
0
0.2
0.4
0.6
0.8
1
1.2
0 20 40 60 80
Time (ps)
Am
plit
ude
(ar
b. u
nit
)
α=1 α=2 α=3 α=4 α=5 α=6
Dispesion penalty @4km (DM)
0
0.5
1
1.5
2
2.5
3
3.5
0 2 4 6 8
alpha
Dispe
rsion penalty (dB
)
1271-1331 1291-1351
Pd=0.33dB Pd=0.7dB Pd=1.12dB Pd=1.6dB Pd=2.18dB Pd=2.87dB
Pd=0.21dB Pd=0.44dB Pd=0.69dB Pd=0.96dB Pd=1.26dB Pd=1.59dB
B2B, ER=6dB, tr/tf=15ps
0
0.2
0.4
0.6
0.8
1
1.2
0 20 40 60 80
Time (ps)
Am
plit
ude
(ar
b. u
nit
)
BtoB
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Summary Wavelength Grid
Optimum Wavelength Grid depends upon distance objective10km: 1291-1351nm- Dispersion penalty of ~1dB
• Better by 0.25dB than 1271-1331nm set. • With α of EA from -1 to 1 (*NOTE 1)
4km: 1271-1331nm- Dispersion penalty of ~1dB (*NOTE 2)
• Better by 0.6dB than 1291-1351nm set. • With α of DM as 4
2km: 1271-1331nm- Dispersion penalty of ~0.5dB
• Better by 0.2dB than 1291-1351nm set. • With α of DM as 4
*NOTE 1: New DM technology required to achieve 10km application due to large α of current DM technology; (α<2 is needed) *NOTE 2: Fixed α was used, therefore the simulation may be optimistic relative to real DML & EA-DFB devices.