1 / 16

S. Hou 15-Jun-2004

Radiation hardness of the 1550 nm edge emitting laser for the optical links of the CDF silicon tracker. S. Hou 15-Jun-2004. Optical links at CDF. Dense Optical Interface Module (DOIM) Byte-wide parallel optical link 8-bits + clock 53 Mbyte/sec, BER  10 -12 Laser transmitter

vanessad
Download Presentation

S. Hou 15-Jun-2004

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Radiation hardness of the 1550 nm edge emitting laser for the optical links of the CDF silicon tracker S. Hou 15-Jun-2004

  2. Optical links at CDF • Dense Optical Interface Module (DOIM) • Byte-wide parallel optical link • 8-bits + clock • 53 Mbyte/sec, BER10-12 • Laser transmitter • Edge-emitting diode array • Ribbon fiber cable (22 m) • multi-mode Ge doped • PIN receiver

  3. DOIM modules • Laser diode transmitters • on Port Cards inside detector • Total 570 transmitters • 128 Port Cards, • PIN diode receivers • on FTM board out in VME crates

  4. Laser transmitter • InGaAs/InP Edge-emitting laser diode array • 1550 nm wavelength • 12-ch diode array, 250 m pitch • Bare die power, 1 mW/ch @20mA • Custom made by Chunghwa Telecom • biCMOS ASIC driver • bipolar transistors, AMS 0.8 m process • Inputs: Diff. ECL or LVDS • differential 100 mV • Enable by TTL low • Output light: adjustable by • ~2mA/0.1V • At Vcc-VLD=3V, 20mA/ch

  5. Laser transmitter assembly • Die-bond / Wire bond • laser-diode array on BeO submount • driver chip on substrate • fibers on V-groove • Alignment • fibers to laser emitting facets • Ligut ouput at fiber end: • 200 ~ 800 W/ch

  6. Receiver module • InGaAs/InP PIN diode • 12-ch array, 1550 nm • by TL, Chunghwa Telecom. • Operation condition : • light on: 50 ~ 800 W • light off: 10 W • 1.1 W/module • Outputs : • Nine independent diff. ECL • Die-bond / Wire bond • PIN-diode array on Al2O3 submount • driver chip on substrate • fibers on V-groove to PIN diodes

  7. Laser transmitter characteristics • Inputs: • ECL or LVDS signal • TTL-enable Light by O/E probe Input ECL TTL enable

  8. Laser transmitter current balance • Constant Current • through LDA or dummy 50 • max. I ~ 7mA/module (<4%) • Prevent wirebond resonance Broken bond observed for 2 mm AlSi bond at 15 kHz Current probe O/E light TTL enable

  9. Laser diode: L-I-V • Laser light at I,V and Temperature • I-V approximately linear • Duty cycle • stable output to input 50% • Linear to temperature Temp (oC)

  10. Rad-hard requirement at CDF • Transmitters on Portcard at r= 15 cm • 450 pb-1 delivered to CDF • TLD (thermoluminescence Dosimeters) measurement ~ 15 rad / pb-1 (5.8E8 MIPs/cm2) CDF luminosity TLD radiaition measurement in CDF tracking volume (http://ncdf67.fnal.gov/~tesarek/radiation) Portcard position

  11. Bulk damage to laser light yield • Laser transmitter specification : 200 krad tolerance • Bulk damage is dominant • Ratio of light drop is consistent for a module, indep. of light power • Degradation10% for 200 krad UC Davis proton 63.3 MeV AC mode on PortCard 200 krad=1.8E12/cm2 (12E12 /cm2 1MeV n) INER proton 30 MeV DC mode 200 krad=1.1E12/cm2(8E12 /cm2 1MeV n)

  12. INER 30 MeV proton Irradiation • transmitter in DC mode • online monitoring light level & temp. • total 1.8 Mrad, 1E13/cm2 (30 MeV p) • 24 hrs annealing with 10% recovery irradiated in 12 cycles, 1 min beam-on 4 min off ripple due to temp. rise at beam-on by 1oC to 25oC

  13. IUCF 200 MeV proton Irradiation • ECL 25MHz inputs • O/E probing for biCMOS driver wave form Before irradiation at fluence=3.0x1013 (1.4 Mrad GaAs 1.8 Mrad Si)

  14. Irradiation study : AC,DC modes • AC mode in 3 flux rate • 3.4, 11.5, 29.2 E9/cm2sec • Cumulative fluence: • 4.3, 12.8, 30 E12/cm2 200MeV p • ( 31, 91, 214 E12/cm2 1MeV n • 200, 600, 1400 krad ) • AC to DC mode • Cumulative fluence: • 6.8, 13.6 E12/cm2 200 MeV p • ( 48, 97 E12/cm2 1MeV n • 320, 640 krad )

  15. Irradiation study: flux rate, annealing • IUCF 200 MeV proton • DC mode, 3 flux rate, • 4.9, 7.2, 13.2 E9/cm2sec • 8 hrs annealing • Cumulative fluence: • 1.7, 5.1, 11.9 E12/cm2 200 MeV p • ( 12, 36, 85 E12/cm2 1 MeV n • 80, 240, 560 krad )  8hrs annealing

  16. Summary • CDF optical links are in stable service • daily maintenance are temperature, ECL related • Radiation tolerance is sufficient for the Run II program • irradiation tests  • laser light degradation is less than 10% at 200 krad • no damage observed on driver chip wave form

More Related