100GE over SMF Using 4x10G DMLand 4x25Gb/s Linear Equalizers
100GE over SMF Using 4x10G DMLand 4x25Gb/s Linear Equalizers
Winston Way, Yuling Zhuang, Jerry Liu, NeoPhotonics
Ali Ghiasi, Fred Tang, Broadcom
Next Gen 100GbE Optical SG, Newport Beach, January 2012
• Kai Cui, Huawei
• Frank Chang, Vitesse
• Ahmet Balcioglu, Hittite
SupportersSupporters
1
IntroductionIntroduction
• The feasibility of using uncooled 1300nm CWDM 10G
DML and 25G equalizer to carry 25Gb/s data is explored
• Potential for 4x25Gb/s short reach SMF (<2km)
application
• Simple, low cost, low power consumption
• Reuse most of the components from today’s 40GBASE-LR4 and
100GBASE-LR4
– CWDM mux & demux (20nm spacing)
– 4x25Gb/s ROSAs
– 4x25Gb/s CDRs
• Possible half re-timed at TX only, or un-retimed
Advantages of the New ApproachAdvantages of the New Approach
• Leverage the potential volume use of 25Gb/s equalizers, which will be
integrated in a CDR or a gearbox, and will be used for MMF and Cu
• Can fit into small modules such as QSFP or CFP2
• Wavelengths compatible with 40G-LR4 for dual speed operations up to
2 km
3
4x
10G DML
uncooled
4x
25G PD
4x
25G CDR
4x
25G EQ
+ CDR
4x
10G DML
uncooled
4x
25G PD
4x
25G LDD
+CDROR
(EQ/CDR in external
gearbox)
OR
4x
10G DML
uncooled
4x
25G PD
4x
25G LDD
4x
25G EQ/
CDR in GB
Experimental & Simulation SetupExperimental & Simulation Setup
I
26GHz
Bias-T
25Gb/s Pulse
Pattern
Generator
500mVpp(emulate CDR 10Gb/s
45ΩΩΩΩ
Adjustable
4
(emulate CDR
or gearbox
single-ended output)
25Gb/s
Receiver
10Gb/s
1270nm
DFB LD
Captured WaveformEqualizer WDP
Analysis
Adjustable
Attenuation
Eye Diagrams at Different Bias LevelsEye Diagrams at Different Bias Levels
I bias = 30 mA
3dB BW= 10.5 GHz
ER= 1.9dB
I bias = 40 mA
3dB BW= 11.1 GHz
ER= 1.3dB
5
I bias = 18 mA
3dB BW= 8.1 GHz
ER= 5.2dB
I bias = 20 mA
3dB BW= 8.9 GHz
ER= 4.0dB
1270nm 10G DML Frequency Response1270nm 10G DML Frequency Response
6
Calculated WDP for Measured Waveforms (PAlloc=5dB)Calculated WDP for Measured Waveforms (PAlloc=5dB)
4
6
8
10
12
WD
P (
dB
)
18mA 20mA 30mA 40mA
7
0
2
4
1FFE 4FFE
6FFE 6FFE_3DFE
1FFE_5DFE 14FFE_5DFE
• At low bias levels (18, 20mA), WDP for a realizable equalizer is >5dBo
• At high bias levels (30, 40mA), WDP for a realizable equalizer is <5dBo
• At high bias levels, WDP remains fairly constant (1FFE+5DFE, 6FFE+3DFE) within the received power range of 5.8dB
(channel insertion loss budget for 2km SMF is 4dB, which includes 2dB connector/splice loss)
-9.0
-6.0
-3.0
0.0
3.0
6.0
S2
1 (d
B)
S21 EO Response (Mitsubishi Laser1_COS14385)
Mitsubishi_80C_30mA
Mitsubishi_80C_40mA
AlGaInAs–InP 10Gbps DFB Lasers-High Bandwidth, High Temperature Operations
AlGaInAs–InP 10Gbps DFB Lasers-High Bandwidth, High Temperature Operations
80-degC
-30.0
-27.0
-24.0
-21.0
-18.0
-15.0
-12.0
0 2 4 6 8 10 12 14 16 18 20
S2
1 (d
B)
Frequency (GHz)
Mitsubishi_80C_50mA
Mitsubishi_80C_65mA
8
• Driver amplifiers: 3dB bandwidth > 19GHz
• 4x10G package: 3dB bandwidth > 17~18GHz
Electronic Components for 10GElectronic Components for 10G
9
• Technical feasibility of using 4x25G 1300nm CWDM DML and 4x25G linear
equalizer (to be integrated in a CDR) for short reach (<2km) SMF is studied via
experiment and simulation
• Due to the replacement of 25G DML or EML by a 10G DML, and the elimination
of 25G laser drivers, there will be a significant cost reduction
• This low cost and low power approach can use a small module such as QSFP
or CFP2
SummarySummary
or CFP2
10
Next StepsNext Steps
1. . Test packaged AlGaInAs–InP 10Gbps DFB Lasers at high
temperature through 2km SMF, with or without driver amps
2. Compare the performance differences between
un-retimed and re-timed configurations
Backup Slide
11
Extra Penalty Due to Smaller ERExtra Penalty Due to Smaller ER
100GE-2km
ER≥1.9dB
~3dB
12
100GE-LR4
ER≥4dB
0.47dB/km x (10km – 2km)= 3.76dB