Joint ITU-T/IEEE Workshop
on The Future of Ethernet Transport
(Geneva, 28 May 2010)
Technologies & Architectures for Next
Gen Ethernet Optical Client Interfaces
Jon Anderson
Director, Technology Programs
Opnext
Geneva, 28 May 2010
Outline
Where have we been
Where are we at
Where are we going
Acknowledgement
The following from Opnext and Hitachi CRL
contributed to this presentation:
K. Hiramoto
M. Okayasu
T. Sugawara
M. Traverso
Geneva, 28 May 2010
2
Client Optical Interface
Evolution
In the past, Datacomm industry has leveraged
Telecom optical technology
We are now in a cross-over period.
Network and Router I/F Speeds (Gbit/s)
Data Rate (Gbit/s)
Telecom optics 1000
growing 4x every
5+ years
100
TDM
10
OC768
OC192 OC192
565M
OC48
OC12
140M
OC3
0.1
Datacomm optics
growing 10x
every 4-5 years
by leveraging
telecom optics
1GE
Ethernet
POS
0.01
80
85
Source: G. Nicholl, M. Nowell / Cisco
Geneva, 28 May 2010
90
40GE
10GE
OC48
1
OC768
OTU4
100GE
95
00
05
Year Introduced
10
15
3
Computing & Networking
Bandwidth Growth
Core networking bandwidth demand is outpacing
optical interface speed
1,000,000
Rate Mb/s
100,000
100 Gigabit Ethernet
Core
Networking
Doubling
≈18 mos
40 Gigabit Ethernet
10,000
10 Gigabit Ethernet
Gigabit Ethernet
1,000
Server
I/O
Doubling
≈24 mos
100
1995
2000
2005
2010
2015
2020
Date
Source: IEEE 802.3 HSSG_Tutorial_1107, Nov. 2007
Geneva, 28 May 2010
4
100GE LAN Interface
1st Gen
Host
Elec I/F
Optical Transceiver Module
1st Gen - CFP
100GE
MAC/
PCS
CAUI
10x10.3G
10:4
4:10
Gearbox
4x25G
100GBASE-LR4
4x25G
L-WDM
Optics
SMF
SiGe
Geneva, 28 May 2010
5
100GE LAN Interface
Future Gen
Host
Elec I/F
Optical Transceiver Module
1st Gen - CFP
100GE
MAC/
PCS
CAUI
10x10.3G
CEI
28G-VSR
4x25G
100G
PHY
10:4
4:10
Gearbox
4x25G
100GBASE-LR4
4x25G
L-WDM
Optics
SMF
Future Gen – X2-like FF
Quad
CDR
4x25G
4x25G
L-WDM
Optics
100GBASE-LR4
SMF
SiGe
CMOS
Geneva, 28 May 2010
6
100GBASE-LR4
Optical Transceiver
1st Generation Technology & Architecture
CAUI
10 x 10.3G
ROSA: TIA/PIN PD/Package
・High-speed/Reliable PIN photo diode
・High-speed (24GHz) FPC/CAN-type PKG
4x 25G λ LAN-WDM
ROSA-PKG
FPC
ROSA PKG
Gearbox ICs
LDs
Optical Mux/Demux
mm
4
14
14 mm
CFP MSA
Geneva, 28 May 2010
77
mm
25G received waveform
[-12dBm(OMA)]
TOSA: semi-cooled EA-DFB
・High output power (OMA=6.3dBm) LAN-WDM grid
・Wide bandwidth (f_3dB > 30GHz) (800GHz pitch)
25.8Gb/s
Optical waveform@60℃
1290
1295
1300
Ref: R. Arima, et al. OFC2010, PDPD3
1305
1310
1315
7
100GBASE-LR4
Optical Transceiver
Future Gen Technology
New technology is required for reducing
transceiver power-consumption, form factor
and cost.
Examination
item
Optical devices
Low loss/ Low
power
consumption
Analogue circuits Low power
Digital circuits
consumption
Optical module
Technology Approach
Technological
opportunity
Monolithic Lens integrated: LISEL, LIPD
Short cavity laser
25 Gb/s SiGe/CMOS IC
Quad CDR IC
Compact/highSIP (Optical MUX/DEMUX and TOSA/ROSAs in one
density packaging Package)
Geneva, 28 May 2010
Ref: T. Sugawara, et al. OFC2010, OThS4
8
25G Direct Modulated
DFB Laser Technology
• Ridge Waveguide DFB-type
InGaAlAs-MQW
•λ = 1300 nm
•Coating front: AR, rear: HR
•Cavity Length: Lc = 160 um
TLD
25ºC
95ºC
Ib
36 mA
65 mA
ER
9.0 dB
7.0 dB
Vpp
2.0 V
2.0 V
Lc = 160 um
BTB
Shortening Lc provides:
40ps
•High bit rate operation
•Lower threshold current
•Saturation power decreasing
•Increased slope efficiency
10km
SMF
Ref: T. Fukamachi et al., ECOC, paper 8.2.5 (2009).
Geneva, 28 May 2010
9
Lens-Integrated
Surface Emitting Laser (LISEL)
Assembly friendly, high-speed 1.3-μm surface emitting laser
Monolithic integration of aspheric InP lens
High output power exceeding 20mW at 85ºC
May be extended to WDM array device
Schematic of SC-LISEL* SEM image of LISEL*
I-L curves
30
lens
lens
200 μm
InP
75μm
*LISEL
**EELD
Etched mirror
Power (mW)
Etched lens
25
LISEL
EELD
20
15
25ºC
10
85ºC
10 Gb/s
5
0
0
50
100
150
: Lens-Integrated Surface-Emitting Laser
Current (mA)
: Edge Emitting Laser Diode
Ref. K. Adachi et al., OFC, paper JthA31 (2009).
Geneva, 28 May 2010
10
Lens Integrated PIN PD
High optical coupling efficiency and wide tolerance with high speed PD
⇨ Small beam spot: ~4um dia. < ~14 um dia. (absorption layer)
Input optical beam
Input optical beam
Fe-InP
InP aspheric lens
Fe-InP
beam spot: ~8 um dia.
(absorption: ~14 um dia.)
Conventional PIN PD
beam spot: ~4 um dia.
(absorption: ~14 um dia.)
Lens Integrated PIN PD (LIPD)
Ref. Y. Lee et al., OECC, paper ThC4 (2009).
Geneva, 28 May 2010
11
Future Gen
100GBASE-LR4
Optical Transceiver
4ch L-WDM 25G DM-LISELs, lens integrated PINPD integrated with PLC mux, demux:
Compact 100GE-LR4 TOSA/ROSA devices & transceiver
Low power consumption: DM-DFB array w/drivers (4.4W) +
TIA/PIN-PD array (0.8W) + quad CDR (2.0W) + DC/DC (0.5) < 8W
X2-like form factor transceiver
CEI 28G-VSR
4 x 25G
Quad
CDR
Geneva, 28 May 2010
4x25G
DM-DFB
Drivers
4x25G
W-LAN
LISELs
4x25G
TIA/PIN
PD Array
4x25G ROSA
4x25G TOSA
4λ
PLC
Mux
4λ
PLC
Demux
100GBASELR4
12
Future Ethernet
Optical Client Interface
Drivers:
Core Networking bandwidth demand scaling:
•
•
Core Transport Rate >> 100G; 1TB in 2015??
Ethernet Client Interface rates: 4x – 10x in 2015
Constraints:
Cost
Power Consumption
Module Form Factor
Geneva, 28 May 2010
13
Future Ethernet
Optical Client Interface
Design Approaches
Increase optics speed
Leverage line-side multi-level modulation,
coherent detection technologies to increase
spectral efficiency
Scale LR4 optical parallel architecture
Scale LR4 optical parallel architecture +
increase optics speed
Others?
Geneva, 28 May 2010
14
Future Ethernet
Optical Client Interface
Scaled LR4 Parallel Architecture: nx25GBASE-LRn
CEI
28G-VSR
n x 25G
n
.
.
.
.
.
.
.
.
.
CDR
n-array
nx25G
DM-DFB
Drivers
n
.
.
.
n
.
.
.
Pro
Pc
nx25G
W-LAN
LISELs
nx25G
TIA/PIN
PD Array
n
.
.
.
n
.
.
.
nλ
PLC
Mux
nλ
PLC
Demux
N
I/F
Rate
(Gb/s)
8
200
10
250
12
300
16
400
Con
May be too high for: 4x (8W for 4ch 100BASE-LR4)
= 32W
FF
Potentially CFP-like w/ improved connector
Cost
Leverages new gen 100GE-LR4 25G optics,
elec devices & integration, packaging
processes
Geneva, 28 May 2010
16λ L-WDM grid spans ~70nm, challenging for DFB
mfg, (monolithic arrays ruled out), leads to high
yield loss, higher TOSA cost
15
Future Ethernet
Optical Client Interface
Scaled LR4 Parallel Architecture with optics speed
increase: 10x40GBASE-LR10
10x40G
CEI
28G-VSR
16 x 25G
.
.
.
.
.
.
16:10/
10:16
Mux/
Demux
gearbox
.
.
.
10x40G
EA-DFB
Drivers
10x40G
.
.
.
Pro
.
.
.
10x40G
W-LAN
LISELs
10x40G
TIA/PIN
PD Array
10
.
.
.
10
.
.
.
10λ
PLC
Mux
SMF
10λ
PLC
Demux
Con
Pc
Gearbox IC is >>10Ws; expect module >> 32W
FF
Requires large volume for heat-sinking; probably
not pluggable in 1st gen
Cost
Leverages 40G optics, electrical devices &
100G-LR4 integration, packaging processes
Geneva, 28 May 2010
10λ L-WDM grid spans ~45nm, still challenging for
DFB mfg, (monolithic arrays ruled out), leads to
high yield loss, higher TOSA cost; higher cost new
gen gearbox IC process needed to reduce power
16
Future Ethernet
Optical Client Interface
Scaled LR4 Parallel Architecture with optics speed
increase: 8x50GBASE-LR8
8x50G
CEI
28G-VSR
16 x 25G
.
.
.
.
.
.
8x
2:1/
1:2/
Bit
mux/
demux
.
.
.
8x50G
EA-DFB
Drivers
.
.
.
8x50G
.
.
.
Pro
Pc
Bit mux IC much easier to implement with
much lower power consumption cf gearbox
FF
Potentially CFP-like w/ improved connector
Cost
8λ L-WDM or possibly CWDM laser yield
much easier to manage, monolithic array
may be in reach for lower cost
Geneva, 28 May 2010
8x50G
LISEL
Array
8x50G
TIA/PIN
PD Array
8
.
.
.
8
.
.
.
8λ
PLC
Mux
SMF
8λ
PLC
Demux
Con
50G EA-DFB not yet proven technology
17
Conclusion
Ethernet optical client interfaces have kept pace
with core network demand by leveraging optical
line side technology
We are at a cross-over point now at 100GE with
given core networking bw need projected to be
4x – 10x by 2015
Integrated parallel optics technologies being
developed for next gen 40G/100GBASE-LR4 will
be leveraged for beyond 100GE client interfaces
A combination of increased optics speeds (25G ->
50G) with 2x 100G-LR4 parallel optics may be
the best approach to achieve > 100GE
Geneva, 28 May 2010
18
Thank You!