1. sTGC Router Optical Transceiver options
Muon Week 2013/09/17
S. Hou
Academia Sinica
Taiwan

2. Outline Optical transceivers Issues on Fabrication, Radiation hardness
Versatile Link project :
CERN TOSA+GBLD driver
LAr SMU TOSA+LOCld driver
Commercial products
SFP+, LightPeak, ..
Issues on
Fabrication, Radiation hardness
Choice and plan LAr Transceiver fits our need?
Activities and plan

3. Outer detector transceivers vs Commercial products
Commercial: telecommunication and computing
10 Gb/s links with SFP+ transceivers for professional facilities
4.8 Gb/s USB3 for personal computing and household electronics
Off-the-shell to HEP
Laser, PIN are commonly rad-hard
TOSA/ROSA, relieved coupling issue
commercial ASICs are not rad-hard?
HEP projects, rad-hard drivers + VCSEL
CERN Versatile links, 850 nm, MM, GBLD (IBM 130 nm)
SMU Multi-TX, 850nm, MM, LOCld (SOS .25 μm)
5 Gbps USB3
CERN
VTRx
10 GB/s SFP+
SMU
MTx

4. CERN TX module SFP format TOSA MM 850nm GBLD driver 5 Gbps
VL, Vasey,
BGT, Moreira,

5. LAr MTX of SMU Similar to CERN VL product, TOSA of MM, 850nm
Use LOCld, driver of SOS process
Speed 8 Gb/s
Different geo/connector configuration
constrain by LAr geometry
TWEPP2012, Liu

6. HEP optical module production, lessons learned
Custom design modules are labor intensive,
Difficulties include:
- alignment for light coupling to fiber
- uniformity in light coupling efficiency
CDF used
V-groove, submount
Poor uniformaty
SCT inner, used
45 deg fiber cuts
as flat mirror
SCT outer, used
Alignment pins on FR4
as flat mirror

7. ATLAS optical failures, lessons learned
SCT outer: suggested cause of ESD, moisture, not yet cured.
LAr OTX: suggested cracks in TOSA packaging (bending leads)
modules replace and cured
Favor VECEL in TOSA package
Air tight in dry nitrogen
OTX
FEB
G-link TX
Epoxy Epo-Tek 353ND over active surface of VCSEL
SMUX
~ 400 mm

8. Evaluation of commercial products, SFP+
Commercial Transceivers :
commonly In TX/RX pair, for computer
drivers plus control chip
control chips are radiation fragile
Newer CMOS chips
maybe very different
10 GB/s SFP+
TWEPP2008, Amaral

9. New generation of optical transceivers
Intel Light Peak project
High speed multiple I/O protocols,
over a single cable
USB3, Active Optical Cable
4.8 Gbps is in market
Module by FOCI investigated
- Bare die VCSEL/PIN (Avago)
IC (VO510 by VIA Labs)
drivers + control, of TSMC CMOS 90nm
- PEI lens coupling to MM fibers

10. Light Peak Optical module
Advantage in packaging
- Bare dies and chip in 2 mm cap, 5 mm wide
Radiation tests :
- Proton SEE 3x x109 p(30MeV)/cm2s
- X-ray TID 380 kRad in 1hr observed 14 SEU
VIA Labs V0510, function

11. VCSEL characteristics
TOSA, flex, pin
VCSEL: Vertical Cavity surface emitting laser diode
GaAs, thin active layer ‹10 μm, very rad-hard
Little temperature dependence
Linear V-I, linear Light output to current
Commonly driven at 10 mA, (2 V).
Burn by over current (>20 mA)
L-I of an VCSEL array of 12 channels

12. VCSEL radiation damage (1)
VCSEL degradation is linear to fluence
independent to Flux rate
Fast annealing by charge injection (~5hr)
operation current (10 nA) applied
Signal speed is not effected
wave form, Bit-Error-Rate tests
L-I of VCSEL (oxide)
vs. online Fluence
L-I of VCSEL (oxide)
vs. Annealing time

13. VCSEL radiation damage (2)
VCSEL in proton radiation
 less damaged with higher proton energy
 conflict with NIEL calculations
GaAs solar cell
Srour, IEEE TNS 50, 653 (2003)
VCSEL (GaAs) at I=10 mA

14. Radiation tests of commercial products
QSFP, miniPOD, PPOD, ONET8501V, ONET1101L
tested with X-ray or γ-ray, none meet the ATLAS LAr radiation requirement.
Kintex 7, ONET8501
tested with a neutrons in Los Alamos SEU rate of Kintex 7 is too high for LAr.
Vendor
Part#
Gbps
# ch
Rad type
(krad/hr)
TID (krad)
QSFP
Avago
AFBR-79EIDZ 10 4
60Co  75
miniPOD
AFBR-810FN1Z 1
x-ray
360 66
PPOD
AFBR-810EPZ 12
150
VCSEL driver TI
ONET8501V 39
178
F-P laser driver
ONET1101L
9.6
464
< 900
Vendor
Part#
# of ch
Flux (n/cm2/s)
Fluence (n/cm2)
# errors
 (cm2)
Kintex-7
Xilinx
XC7K325TFFG900 16
(2 tested)
4.6E5
2.1E11
4/4
(2 shared)
1.6E-11
VCSEL driver TI
ONET8501V 1
< 5E-12
SMU, TWEPP2012

15. sTGC router transceiver, choices
1. Use VCSEL in TOSA 850 nm, MM, 10 GHz
 no fiber alignment issue, TOSA takes LC fiber connecter production is plainly PCB SMD process
2. Choice of GBLD or LOCld drivers
3. Joint Optical project of Phase-I LAr+NSW ? Requires approval
LAr MTX is rad-hard, up to 8 Gbps (Xcheck?)
LAr requires 5000 lines
sTGC router is satisfied? Total 800 lines
only QA, no R&D required
Test fanout board, SMA to I/O
e.g. Kintex7, Scope
SMU MTX module

16. Preparations Manufacturers in contact 1. Liverag.com.tw 2. FOCI.com.tw
Expertise on active optical products
Capable of >10Gbps modules, QA, circuits
2. FOCI.com.tw
Expertise on passive fiber assemblies
Jointly with SMU, a visit to manufacturers
is planned in early October
 seeking all kind of
collaboration opportunities
and cost estimation
Laboratory setup
Bench test, scope for 10 GHz eye diagram
Bit Error Rate using Kintex7 board
Radiation tests, Co60 gamma, proton 30 MeV

17. Summary Propose to choose from LAr optical link options
 using the same transceiver
 joint fabrication options
Double check on LAr products
 to quickly build up coherent expertise
 work out router board protocol and functions