294K

1. R&D Towards Cryogenic Optical Links room temperature, 5.2 Gbps Mark Christiansenb, Jeremy Doddc, Raphael Galeac†, Datao Gongd, Robert Hackenburga, SuenHoue, David Lissauera, ChonghanLiud††, TiankuanLiud, VeljkoRadekaf, PavelRehakf, John Sonderickerd, RyszardStroynowskid, Da-Shung Sue, Peter Takacsf, HelioTakaia, ValeriTcherniatinea, Ping-Kun Tenge, Craig Thorna, William Willisb, Annie C. Xiangd, JingboYed, Bo Yuf a Physics Department, Brookhaven National Laboratory, Upton, NY 11973, U.S.A. b Department of Electrical Engineering, Southern Methodist University, Dallas TX 75275, U.S.A. c Department of Physics, Columbia University, New York, NY 10027, U.S.A. d Department of Physics, Southern Methodist University, Dallas TX 75275, U.S.A. e Institute of Physics, Academia Sinica, Nangang 11529, Taipei, Taiwan f Instrumentation Division, Brookhaven National Laboratory, Upton, NY 11973, U.S.A. g National Research Council of Canada, Ottawa, ON, K1A0R6, Canada liu@mail.physics.smu.edu Introduction Abstract Components Tested We present electrical and optical measurement results on critical components from room temperature to 77 K (liquid nitrogen), 4.2 K (liquid helium). We have identified a CMOS technology, passive components and found promising laser diodes for the development of optical links operating inside a liquid argon time projection chamber. • SOS CMOS : Individual MOSFETs, Ring Oscillators,16:1 Serializer • SM&MM Fibers and SM&MM optical connectors • Lasers : VCSEL, DFB, FP Individual Transistor Ring Oscillator 0.25 μm Silicon-on-Sapphire (SoS) CMOS Technology Optical Fibers and Connectors NMOS 2.5 μm/0.25 μm/16 PMOS 2.5 μm/0.25 μm/16 Fiber : Single Mode SMF28 Multi Mode InfiniCor SX+ The ring oscillator functions from room temperature to 4.2 K. The frequency increases about 50% with the temperature decreasing from 300 K to 4.2 K Waveform at 4.2 K Connectors: Single Mode F1-8005 Zirconia Sleeve Multi Mode F1-8000 Phosphor Bronze The waveform at 4.2 K has higher amplitude and faster transient times than those at room temperature. • As temperature decreases • Absolute value of threshold voltage (|VT|) increases • Transconductance (gm) peaks around 100 K Serializer1 Power consumption: VDD = 1.8 V 250 mW VDD = 2.5 V 500 mW • The chip functions well with VDD = 1.8 V. Below this the bit error rate goes above 10-12 VDD = 1.8 V 77 K, 5.2 Gbps • At 77 K the serializer has a wider open eye diagram with faster rise, fall time, smaller jitters and larger amplitude than those at room temperature. • Due to hot carrier effects, chip reliability may be reduced at cryogenic temperature. To mitigate this problem, we probe the possibility of operating this chip at lower power supply voltages. The light attenuation per meter of fibers and coupling loss of connectors at 77 K are negligible compared to normal optical link power budget of 10 dB. Lasers 215K 77K 296K 110K 110K VCSEL 850 nm multi mode 296K 77K 77K 77K 77K 171K 116K 111K 125K 272K 294K 296K 296K 294K 79K DFB 1570 nm single mode • Possible candidates from DFB and FP lasers • VCSEL may need more investigations from more vendors • Reliability studies are ongoing FP 1310 nm single mode Reference 1 Development of A 16:1 serializer for data transmission at 5 Gbps , Datao Gong et al, presented at the topical workshop on electronics in particle physics (TWEPP), Paris, France, Sep. 21-25, 2009. Conclusion Acknowledgments • Gary Evans from EE at Southern Methodist University, technical assistance • Jim Guenter, KhuranaPritha and Bob Biard from Finisar, lasers and theoretical assistance • Arthur Mantie and Mark Schuckert from Macomtech, lasers and technical assistance • Todd Huffman and Anthony Weidberg from Oxford, technical assistance • Francois Vasey and Jan Troska from CERN, technical assistance • Tengyun Chen from USTC, lasers and technical assistance Ring oscillators, individual MOSFETs, and a 16:1 5 Gbps serializer fabricated in a commercial 0.25 μm Silicon-on-Sapphire (SoS) CMOS technology function throughout the temperature cycling from room temperature to 4.2 K, 15 K, and 77 K respectively. Optical fibers and optical connectors exhibit small attenuation changes and coupling loss changes respectively at 77 K. VCSEL, DFB and FB lasers lase throughout temperature range 300 K - 77 K. The tests carried out demonstrate feasibility of optical links operating inside the Liquid Argon Time Projection Chamber .