Updates on Optical Projects  June, 2011 B. Fernando,  P.M. DeLurgio,  R. Stanek,  B. Salvachua,  D. Underwood  ANL-HEP D. ...
Motivation <ul><li>Develop and adapt new technologies to improve optical communication in HEP experiments </li></ul><ul><u...
Issues with Current HEP Optical Links <ul><li>Most LHC optical link failures are due to VCSEL failures and broken solder j...
Proposed Optical Scheme  (ideal) August 22, 2011 <ul><ul><li>High bandwidth :  </li></ul></ul><ul><ul><ul><li>no chirp   ...
Detector Applications: Requirements <ul><li>Calorimeters (Tile, Liquid Argon): </li></ul><ul><ul><li>Highly serialized dat...
MODULATORS <ul><li>Technologies </li></ul>August 22, 2011
on off a-Si GeSi a-Si a-Si GeSi a-Si Tapered vertical coupler MIT Design of GeSi EAM Device Structure Liu et al, Opt. Expr...
41 mW at 5 Gb/sec 100 u long  x 10 u wide Thin,  order u Broad spectrum  7.3 nm at 1550 80 u long delay line  internal 1V ...
Advances are Needed in Procuring Modulators <ul><li>ANL Bench tests use LiNO3 modulators – fast, rad hard, but not small <...
Collaboration with industry <ul><li>Testing radiation hardness of commercial modulators </li></ul><ul><li>Design and const...
The Luxtera/Molex Commercial Devices Good Unknown Fast (4x 10G) Radiation hardness Design is very close to our ideal desig...
The Luxtera/Molex design [ link ]
Testing Plan for (Jenoptik/Molex)  <ul><li>Test the operation at -20C </li></ul><ul><li>Few Total Ionizing Dose (TID) test...
FUTURE
Future Directions <ul><ul><ul><li>Test radiation hardness and low temperature operation of Commercial modulators  and impr...
Backup August 22, 2011
Optical links failures at LHC <ul><li>VCSEL failures in ATLAS before beam  http://www.sciencedirect.com/science/article/pi...
BEAMS IN AIR <ul><li>Technologies </li></ul>August 22, 2011
Technology : Free-Space Communication to replace fibers and cables <ul><li>Advantages: </li></ul><ul><ul><li>Low Mass  </l...
Main Parts of Project <ul><li>Design of lens systems  to send and receive modulated laser light  through free space.  </li...
<ul><li>The commercial MEMS mirrors have ~40 dB resonance peaks at 1 and 3 KHz. </li></ul><ul><li>To use the direct feedba...
Feedback from Reflections <ul><li>A q uadrant  detector is used to find the  position of the receiver </li></ul><ul><ul><l...
After Quadrant Detector and Alignment Beam Fixed  <ul><li>Quadrant detectors are now designed for optimum sensor separatio...
Different Feedback Mechanisms  <ul><li>Implemented few feedback systems to study the capture efficiency. In order to  unde...
Different Feedback Mechanisms (2) <ul><li>Simple feedback:  Here, the feedback from the quadrant detector, with an X and Y...
Different Feedback Mechanisms (3) <ul><li>Power feedback:  Quadrant detector not used. Here, the feedback from the capture...
Different Feedback Mechanisms (4)  <ul><li>Mapped feedbacks : The quadrant detector  (QD) response is mapped to movement o...
Our Current Version CW LASER 1550 nm optical    electric ADC TIA  DAC SPI SPI X Y X Y Amp MEMS Mirror to steer Small  Pri...
RECEIVER Digital  Processing MEMS Steering Setup  Reflecting Lens GRIN LENS To Fiber FPGA Pseudo Random Data, Bit Error Ra...
The figures show a 3D finite element analysis of the MEMS designed. The upper panel shows the top view of the mirror and t...
Accomplishments in Beams in Air <ul><li>Steering using reflections from the receiver system, without wires. We made a majo...
LONG DISTANCES  <ul><li>Applications </li></ul>
1 Gb/s over 80 Meters Long Range Free-Space Communication Telescope   Building a fast small distance positioner for the re...
Technology :  MEMS Mirrors The Lucent Lambda Router: A commercially available MEMS mirror (Developed at ARI, Berkeley)
<ul><li>Studied in detail the properties of asphere and GRIN lenses  </li></ul><ul><li>to find the best option to send/rec...
Beams in Air: Size vs Distance <ul><li>The Rayleigh distance acts much like Beta-Star in accelerators  </li></ul><ul><ul><...
Bit Error Tester <ul><li>FPGA based bit error tester that can be customized for  </li></ul><ul><ul><li>line rate, datapath...
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Anl Optical

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Anl Optical

  1. 1. Updates on Optical Projects June, 2011 B. Fernando, P.M. DeLurgio, R. Stanek, B. Salvachua, D. Underwood ANL-HEP D. Lopez ANL Center for Nanoscale Materials August 22, 2011
  2. 2. Motivation <ul><li>Develop and adapt new technologies to improve optical communication in HEP experiments </li></ul><ul><ul><li>Increase speed, reduce the mass of the system, Increase reliability </li></ul></ul><ul><li>Test operation of new devices with the environmental conditions of </li></ul><ul><ul><li>Radiation hardness, low temperature operation, Reliability </li></ul></ul><ul><li>Introduce the technologies to real detectors </li></ul><ul><li>Investigate techniques to eliminate fibers, cables and connectors </li></ul>August 22, 2011
  3. 3. Issues with Current HEP Optical Links <ul><li>Most LHC optical link failures are due to VCSEL failures and broken solder joints </li></ul><ul><ul><li>More spare links (?) </li></ul></ul><ul><li>VCSELs need </li></ul><ul><ul><li>High current driver chips (radiation hard) which need a lot of power and control wires </li></ul></ul><ul><ul><li>Power cables (to supply current) </li></ul></ul><ul><ul><li>Need to tune links individually (need control wires) </li></ul></ul><ul><ul><li>Cooling/Heating </li></ul></ul><ul><li>ESD/moisture sensitivity </li></ul><ul><ul><li>Issue with custom packaging (non industry) </li></ul></ul><ul><li>High current density </li></ul><ul><li>Radiation tolerance </li></ul><ul><ul><li>  Commercial VCSEL's have  only limited radiation tolerance, which is probably not adequate </li></ul></ul>Increase Amount of material inside detector Reliability issues
  4. 4. Proposed Optical Scheme (ideal) August 22, 2011 <ul><ul><li>High bandwidth : </li></ul></ul><ul><ul><ul><li>no chirp  commercial systems work >10 Gb/s/channel </li></ul></ul></ul><ul><ul><li>Low material budget : </li></ul></ul><ul><ul><ul><li>Less total power inside detector  less cooling needed (stainless steel/copper) </li></ul></ul></ul><ul><ul><ul><li>Fewer control wires </li></ul></ul></ul><ul><ul><li>Higher reliability : </li></ul></ul><ul><ul><ul><li>Laser sources outside the detector, </li></ul></ul></ul><ul><ul><ul><li>Don’t need separate high current drivers, less radiation/ESD/humidity sensitivity </li></ul></ul></ul><ul><ul><li>Smaller in size </li></ul></ul><ul><ul><ul><li>Modulators/PIN diodes can be integrated into a single die </li></ul></ul></ul>n n Power On detector (n=12?) Outside (counting room) Fibers /free space links CW laser Fibers Single chip Modulator*n PIN diode*n Data, TTC TIA AMP Single chip (possibility in future) Modulator*n PIN diode*n TIA*n AMP*n Control Chip /sensors
  5. 5. Detector Applications: Requirements <ul><li>Calorimeters (Tile, Liquid Argon): </li></ul><ul><ul><li>Highly serialized data  fast (8-10 Gb/s links) </li></ul></ul><ul><ul><li>Less radiation ( ~10 13 Protons/cm 2 ) </li></ul></ul><ul><ul><li>Standard interface with industry standards (snap 12?) </li></ul></ul><ul><ul><li>Reliability is an issue because there can be no access for years </li></ul></ul><ul><li>Tracker(pixel detector, silicon tracker) </li></ul><ul><ul><li>More data  fast (atlas pixel: 5Gb/s out) </li></ul></ul><ul><ul><li>High radiation (~10 15 Protons/cm 2 ) </li></ul></ul><ul><ul><li>Low temperature operation (~-20 C ) </li></ul></ul><ul><ul><li>Reliable (no access after the detector closed) </li></ul></ul><ul><ul><li>Low power consumption (VCSEL based ~40mW/channel) </li></ul></ul><ul><ul><li>Less mass (material inside) </li></ul></ul><ul><ul><li>Custom interface (LVDS input) </li></ul></ul>
  6. 6. MODULATORS <ul><li>Technologies </li></ul>August 22, 2011
  7. 7. on off a-Si GeSi a-Si a-Si GeSi a-Si Tapered vertical coupler MIT Design of GeSi EAM Device Structure Liu et al, Opt. Express. 15, 623-628 (2007) MIT Modulators <ul><li>Fabricated with 180 nm CMOS technology </li></ul><ul><li>Small footprint (30 µm2) </li></ul><ul><li>Extinction ratio: 11 dB @ 1536 nm; 8 dB at 1550 nm </li></ul><ul><li>Operation spectrum range 1539-1553 nm (half of the C-band) </li></ul><ul><li>Ultra-low energy consumption (50 fJ/bit, or 50 µW at 1Gb/s) </li></ul><ul><li>GHz bandwidth </li></ul><ul><li>3V p-p AC, 6 V bias </li></ul><ul><li>Same process used to make a photodetector </li></ul>
  8. 8. 41 mW at 5 Gb/sec 100 u long x 10 u wide Thin, order u Broad spectrum 7.3 nm at 1550 80 u long delay line internal 1V p-p AC, 1.6V bias IBM Modulators
  9. 9. Advances are Needed in Procuring Modulators <ul><li>ANL Bench tests use LiNO3 modulators – fast, rad hard, but not small </li></ul><ul><li>MIT and IBM have prototypes of modulators to be made inside CMOS chips </li></ul><ul><ul><li>It would cost us several x $100k for 2 foundry runs to make these for ourselves </li></ul></ul><ul><ul><li>Currently both designs are not being actively pursued </li></ul></ul><ul><li>We may have found a vendor (Jenoptik) for small modulators who will work with us on ones which can be wire-bonded and have single-mode fiber connections </li></ul><ul><ul><li>Need to test for radiation hardness of these </li></ul></ul><ul><li>There are commercial transceiver of small size such as LUX5010A ( http://ieeexplore.ieee.org/xpls/abs_all.jsp?arnumber=4528356&tag=1 ) </li></ul><ul><ul><li>Fit most of the requirements, need to find out radiation hardness and low temperature operation </li></ul></ul>
  10. 10. Collaboration with industry <ul><li>Testing radiation hardness of commercial modulators </li></ul><ul><li>Design and construct a radiation-hard silicon modulator chip </li></ul><ul><li>Building a transceiver </li></ul><ul><li>Communication within different layers to improve the trigger efficiency </li></ul>August 22, 2011
  11. 11. The Luxtera/Molex Commercial Devices Good Unknown Fast (4x 10G) Radiation hardness Design is very close to our ideal design Low temperature operation Fibers are pure glass, no plastic inside No need of connectors, drivers pin diodes, etc. Very small
  12. 12. The Luxtera/Molex design [ link ]
  13. 13. Testing Plan for (Jenoptik/Molex) <ul><li>Test the operation at -20C </li></ul><ul><li>Few Total Ionizing Dose (TID) testing rounds at ANL with electrons </li></ul><ul><ul><li>Test unmodified devices first. </li></ul></ul><ul><ul><li>Can give some feedback and If request for modifications to standard device is accepted these also to be tested </li></ul></ul><ul><ul><li>Test using 200 MeV protons up to 10 15 Protons/cm 2 </li></ul></ul><ul><ul><li>Couple of batches (improve/unmodified..etc) </li></ul></ul>
  14. 14. FUTURE
  15. 15. Future Directions <ul><ul><ul><li>Test radiation hardness and low temperature operation of Commercial modulators and improve it for HEP optical links </li></ul></ul></ul><ul><ul><ul><li>Build HEP modulators if funding obtained (collaboration with industry ) </li></ul></ul></ul><ul><ul><ul><li>More robust long distance optical link </li></ul></ul></ul><ul><ul><ul><li>Local triggering using optical communication between tracking layers </li></ul></ul></ul>Some concepts for interlayer communication for input to trigger decisions
  16. 16. Backup August 22, 2011
  17. 17. Optical links failures at LHC <ul><li>VCSEL failures in ATLAS before beam http://www.sciencedirect.com/science/article/pii/S0168900208010474 </li></ul><ul><li>VCSEL failures meeting https://indico.cern.ch/getFile.py/access?contribId=8&resId=0&materialId=slides&confId=103879 </li></ul><ul><li>ACES meeting on optical links https://www.ncc.unesp.br/its/attachments/download/119/OptoWG_ACES2011.pdf shows few failures in CMS </li></ul><ul><li>TWEPP 2010 CMS operations &quot;We continue to have failures of the optical links&quot;  (off detector) </li></ul><ul><li>https://wiki.lepp.cornell.edu/lepp/pub/People/AndersRyd/100924_TWEPP.pdf </li></ul><ul><li>LHCB VCSEL failures https://indico.cern.ch/getFile.py/access?contribId=3&sessionId=0&resId=1&materialId=slides&confId=126772 </li></ul><ul><li>CERN Twiki on VCSEL failures  (TT and IT ) https://lbtwiki.cern.ch/bin/view/ST/VCSELs </li></ul>
  18. 18. BEAMS IN AIR <ul><li>Technologies </li></ul>August 22, 2011
  19. 19. Technology : Free-Space Communication to replace fibers and cables <ul><li>Advantages: </li></ul><ul><ul><li>Low Mass </li></ul></ul><ul><ul><li>No fiber routing </li></ul></ul><ul><ul><li>Low latency (No velocity factor) </li></ul></ul><ul><ul><li>Low delay drift (No thermal effects such as in fibers) </li></ul></ul><ul><ul><li>Work over distances from few mm (internal triggers) to ~Km (counting house) or far ( to satellite orbit) </li></ul></ul><ul><ul><li>Communicate between ID layers for trigger decisions. </li></ul></ul>
  20. 20. Main Parts of Project <ul><li>Design of lens systems to send and receive modulated laser light through free space. </li></ul><ul><li>Incorporate modulators to modulate the laser beam </li></ul><ul><li>Use MEMS mirror to guide the beam to the receiver and the use of a feedback mechanism to keep the beam locked to the receiver. </li></ul><ul><li>Setup for bit error rate testing </li></ul><ul><li>Demonstrate practical application, e.g. ANL DHCAL at Fermilab  (this application not yet funded) </li></ul>August 22, 2011
  21. 21. <ul><li>The commercial MEMS mirrors have ~40 dB resonance peaks at 1 and 3 KHz. </li></ul><ul><li>To use the direct feedback, developed an inverse Chebyshev filter which has a notch at 1 kHz, and appropriate phase characteristics (Left Figure) </li></ul><ul><li>With the filter we were able to make the beam follow a reflecting lens target within about 10 μm when the target moved about 1 mm (Right Figure). </li></ul><ul><li>Still has some fundamental issues at large excursion (~1 cm) </li></ul><ul><ul><li>A separate feedback link solves this issue </li></ul></ul>The amplitude-frequency map of our analog feedback loop, demonstrating phase stability at 100 Hz. A test setup used to demonstrate MEMS mirror steering with an analog control loop which compensates for the mirror resonances at 1 and 3 KHz. Studies of Direct Feedback Concept
  22. 22. Feedback from Reflections <ul><li>A q uadrant detector is used to find the position of the receiver </li></ul><ul><ul><li>Is it possible to find the absolute position of the receiver? </li></ul></ul><ul><ul><li>Effects of: </li></ul></ul><ul><ul><ul><li>Size of the beam spot at detectors </li></ul></ul></ul><ul><ul><ul><li>Surface radius of the reflecting lens (hard to find many lenses) </li></ul></ul></ul><ul><ul><ul><li>Size of the reflecting lens </li></ul></ul></ul><ul><ul><ul><li>Distance between the detectors </li></ul></ul></ul>August 22, 2011 Different issues we understood and later fixed Beam too small Detector too small
  23. 23. After Quadrant Detector and Alignment Beam Fixed <ul><li>Quadrant detectors are now designed for optimum sensor separation </li></ul><ul><ul><li>Limited working range is due to the size of the reflecting lens </li></ul></ul>August 22, 2011 x y This is better since the x-y correlations are insignificant and most of the part is it linear.
  24. 24. Different Feedback Mechanisms <ul><li>Implemented few feedback systems to study the capture efficiency. In order to understand the efficiency we measured the captured optical power </li></ul>August 22, 2011 <ul><li>No feedback: receiving lens was moved (simple x-y translation) and power measured and fit the distribution to a 2D Gaussian </li></ul><ul><ul><li>FWHM: 1.33 mm </li></ul></ul>Distance in X (mm) Distance in Y(mm) Distance in X (mm) Distance in Y(mm) transmitter receiver MEMS (fixed)
  25. 25. Different Feedback Mechanisms (2) <ul><li>Simple feedback: Here, the feedback from the quadrant detector, with an X and Y analog calculator, is used to move the MEMS mirror so that the reflected beam is again centered on the quadrant detector while the receiving lens is translated. </li></ul>August 22, 2011 <ul><li>FWHM: 4.3 mrad </li></ul>reflector transmitter receiver MEMS (moving) feedback
  26. 26. Different Feedback Mechanisms (3) <ul><li>Power feedback: Quadrant detector not used. Here, the feedback from the captured power is used to move the MEMS mirror so that the beam gives maximum receiver power while the receiving lens is translated. </li></ul>August 22, 2011 <ul><ul><li>FWHM: ~20 mrad </li></ul></ul>transmitter receiver MEMS (moving) feedback
  27. 27. Different Feedback Mechanisms (4) <ul><li>Mapped feedbacks : The quadrant detector (QD) response is mapped to movement of the receiver in an initial alignment phase. The initial alignment done </li></ul>August 22, 2011 <ul><ul><li>FWHM: ~10 mrad </li></ul></ul><ul><ul><li>FWHM: ~9.5 mrad </li></ul></ul><ul><li>With power feedback and used a fit </li></ul><ul><li>Alignment link separately which fill a Look Up Table (LUT) </li></ul>1 2 transmitter receiver MEMS (moving) feedback feedback
  28. 28. Our Current Version CW LASER 1550 nm optical  electric ADC TIA DAC SPI SPI X Y X Y Amp MEMS Mirror to steer Small Prism 850 nm LASER For alignment Reflection Reflective lens Rigid Coupling GRIN lens to Capture wires wires 1550 LASER Beam Modulator Asphere Lens to launch Si Detectors This Assembly moves SFP FPGA Bit Error Tester FPGA Lookup table Digital filter
  29. 29. RECEIVER Digital Processing MEMS Steering Setup Reflecting Lens GRIN LENS To Fiber FPGA Pseudo Random Data, Bit Error Rate Standard Fiber Receiver Modulator Launch Lens MEMS Mirror Quad Detector and Steering Laser
  30. 30. The figures show a 3D finite element analysis of the MEMS designed. The upper panel shows the top view of the mirror and the bottom panel a bottom view. <ul><li>Argonne Center for NanoScale Materials, CNM, has designed and simulated novel MEMS mirrors that should solve the problems of commercial mirrors </li></ul><ul><ul><li>The mirror is supported laterally and it can be actuated using 4 torsional actuators located in the vicinity. </li></ul></ul><ul><li>More stable mirror with better mechanical noise rejection. </li></ul><ul><li>Under fabrication and we expect to have them available for testing very soon. </li></ul>Technology : Argonne MEMS Mirrors
  31. 31. Accomplishments in Beams in Air <ul><li>Steering using reflections from the receiver system, without wires. We made a major improvement by separating data link and the alignment link. </li></ul><ul><li>Found ways to form beams and receive beams that reduce critical alignments, reducing time and money for setup. </li></ul><ul><li>1.25 Gb/s over 1550 nm in air, using a modulator to impose data, and FPGA to check for errors, <10 -14 error rate, with target moving about 1 cm x 1 cm at 1 m. </li></ul><ul><li>Control of MEMS mirror which has high Q resonance (using both Analog and Digital filter) </li></ul>August 22, 2011
  32. 32. LONG DISTANCES <ul><li>Applications </li></ul>
  33. 33. 1 Gb/s over 80 Meters Long Range Free-Space Communication Telescope   Building a fast small distance positioner for the receiver with tiny servos
  34. 34. Technology : MEMS Mirrors The Lucent Lambda Router: A commercially available MEMS mirror (Developed at ARI, Berkeley)
  35. 35. <ul><li>Studied in detail the properties of asphere and GRIN lenses </li></ul><ul><li>to find the best option to send/receive the laser beam in air </li></ul><ul><li>Transmitter on MEMS mirror (Data Laser) </li></ul><ul><li>We knew that aspheres can produce the best beam to transmit but aspheres have very restricted acceptance angle. Important for capture lens. </li></ul>The Lens System(s) August 22, 2011 Asphere Lens Type Beam FWHM (mm) at 1m Beam Peak Power at 1m (uW/(0.2 x 0.2) mm 2 ) Short (EFL=6.24mm) 1.00 96.51 Medium (EFL=11 mm) 1.68 39.22 Long (EFL=15.3 mm) 2.26 22.60 Lens Types Beam FWHM (mrad) at 1m Total Captured Peak Power ( μ W) θ φ Short Asphere (EFL=6.24mm) 1.64 1.73 179.7 Long Asphere (EFL=15.3 mm) 2.09 1.82 198.4 GRIN with SM 2.66 2.81 48.9 GRIN with MM 20.34 18.60 85.11
  36. 36. Beams in Air: Size vs Distance <ul><li>The Rayleigh distance acts much like Beta-Star in accelerators </li></ul><ul><ul><li>Relates waist size and divergence </li></ul></ul><ul><ul><li>Depends on wavelength </li></ul></ul><ul><li>If we start with a diameter too small for the distance of interest, the beam will diverge, and will become 1/r 2 at the receiver, and we will have large losses (We can still focus what we get to a small device like an APD or PIN diode ). This is typical of space, Satellite, etc. applications. </li></ul><ul><li>If we start with an optimum diameter, the waist can be near the receiver, and we can capture almost all the light and focus it to a small spot </li></ul><ul><li>Examples, ~ 1 mm for 1 m, ~ 50 mm for 1 Km </li></ul>Due to diffraction, there is an optimum diameter for a beam for a given distance in order to reduce 1/r 2 losses
  37. 37. Bit Error Tester <ul><li>FPGA based bit error tester that can be customized for </li></ul><ul><ul><li>line rate, datapath width, TX pre-emphasis and post-emphasis, TX differential swing, RX equalization </li></ul></ul><ul><ul><li>Different patterns PRBS 7-bit, PRBS 15-bit, PRBS 23-bit, PRBS31-bit, user defined. </li></ul></ul>August 22, 2011 <ul><li>Control through the computer to sweep , TX pre-emphasis and post-emphasis, TX differential swing, RX equalization, Rx sampling point to optimize the error free region </li></ul>

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