Lots of funny things from the OptoLinks

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Lots of funny thingsfrom the Opto-Links
Opto-Link Group Wuppertal
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1. Single Event Upsets - Cyclotron

• Opto-link was placed into the beam of the
  Nuffield Cyclotron in Birmingham.
• D Ag --gt n Y
• flux 1.1x106 n/s
• beam energy 18 MeV
• neutron spectrum with broad peak at 9 MeV
• two scans of BER vs. optical power were done,
  with and without beam
• no significant rate of SEU effects were detected.

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1. Single Event Upsets - Cyclotron
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1. Single Event Upsets - Cyclotron
BER of 10-9 is upper limit longer runs showed BER
below 10-9
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2. BER of VDC at 80Mbit/s

• ,,quick and dirty" test
• VDC was supplied with 8-bit-bursts within 32 bits
• up to 240 Mbits/s
• oscilloscope in infinite persistence mode
• bit error-rate better than 1 x10-6

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2. BER of VDC at 80Mbit/s
8 bit bursts at 240 Mbit/s
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2. BER of VDC at 80Mbit/s

• Results with quick and dirty test were
  encouraging
• new test was set up
• discriminator to filter the spikes
• BER lt 8 x 10-13

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3. Review of GEC package
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3. Review of GEC package
Production schedule

• Phase 2 2 pre-prototype devices 2 month after t0
  (one mask production)
• 60 devices 5-7 months after t0
• (t0 time when GEC receives the contract)

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4. Lightscan of packages

• GEC package with 2 MITEL VCSEL and a separate lid
  (fibres glued in)
• OSU package with 2 MITEL VCSEL and a lid
• test if lid mounting is reproducible
• with active alignment 100 mW maximum (If10mA),
  NOT reproducible
• lightscan

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4. Lightscan of packages
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4. Lightscan of packages
NOT TRUE TO SCALE !
GEC package
OSU package
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4. Lightscan of packages
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4. Lightscan of packages
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5.Test of VCSEL in a high magnetic field

• a GEC package with MITEL VCSEL driven by a VDC
• magnetic field rampable up to 8 Tesla

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5.Test of VCSEL in a high magnetic field
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5.Test of VCSEL in a high magnetic field
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5.Test of VCSEL in a high magnetic field

• 40 MHz _at_2Tesla

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6. Speed of irradiated PIN diodes

• The response speed of radiated and un-irradiated
  epitaxial Silicon PIN diodes were measured
• Clean and fast signal waveforms could be obtained
  for the PINs exposed to the highest fluences
  expected for the B-Pixel layer for a bias voltage
  as low as about 5V
• It is possible to use a 5V supply for the PIN
  bias, but it is safer to allow for a 10V supply.

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6. Speed of irradiated PIN diodes
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6. Speed of irradiated PIN diodes
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Conclusions

• The ATLAS SCT/pixel optical links have been
  tested at fluxes up to those expected for the
  SCT. No significant rate of Single
  Event Upset effects were detected.
• The VDC/VCSEL has been tested at a data rate of
  80Mbits/s. No rise in the BER was observed.
  --gt BER lt 8 x 10-13
• Lightscans of both packages showed problems in
  the mechanics of both packages, OSU and GEC

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Conclusions

• There was no significant change in either the DC
  or AC behaviour of the VCSEL in a magnetic field
  up to 6T
• Clean and fast signal waveforms could be obtained
  for the PINs exposed to the highest fluences
  expected for the B-Pixel layer for a bias voltage
  as low as about 5V
• http//www.uni-wuppertal.de/FB8/groups/Drees/detla
  b/optolink.html