A photonic network for data acquisition systems for deep-sea neutrino telescopes

1. A photonic network for data acquisition systems for deep-sea neutrino telescopes Presentation on behalf of the KM3NeT consortium by Jelle Hogenbirk Home institute: Nikhef Amsterdam

2. This talk is dedicated to Dr. Charles Kao physics Nobel prize winner 2009 The part of this year's award associated with Mr. Kao underscores the fact that optical fibers carry an increasing fraction of phone calls, television programs, and internet traffic into homes. Data can move down silicon fiber more quickly than through copper wire because nothing is faster than light, and light signaling offers higher bandwidth for electronic circuitry. Encoding information in the form of light pulses rather than as electric pulses allows more data to flow down a line. Kao's principal achievement was in making the fiber more efficient; by excluding impurities in the fiber material, he developed a material that absorbed less of the light carrying signals over long distances. For more information please consult: http://www.ieeeghn.org/wiki/index.php/Oral-History:Charles_Kao Jelle Hogenbirk et.al.

3. Outline of this talk • Requirements • System setup • CW lasers (continuous wave) • R-EAM’s (reflective electro absorption modulator) • DWDM technology (Dense Wavelength Division Multiplexer) • bidirectional optical signaling with multiple λ’s /fibre • Realized items • Further developments Development team: Peter Healey 1 Mar van der Hoek 3 Jelle Hogenbirk 2 Peter Jansweijer 2 Sander Mos 2 Henk Peek 2 David Smith 1 1 Center for Integrated Photonics 2 Nikhef 3 VanderHoekPhotonics Jelle Hogenbirk et.al.

4. A facility network • 3 years ago and taking progress in technology in account the starting point for the DAQ system requirements were: • All data to shore • Preferable: synchronous data readout • Integrated clock and event time system • Proven technology including COTS (commercial of the shelf) components • A node network for about 6000 clients. • Flexible interfacing to the network must be guaranteed over its life time of > 15 years after deployment. • Taking KM3NeT scale into account, optimize designs in electrical power consumption on seabed facility dependence to RAMS (reliability, availability ,maintainability, safety) criteria and keep the network affordable Jelle Hogenbirk et.al.

5. electronic-photonic front end design idea CW + readout clock pulse Later the clk pulse is the “heartbeat” ~ 7ns Photonic pulse stream e.g. every 2 nsec Trigger all Zener diodes at the same time and The delay times are tuned to 100 ps From PMT’s Pulse detector& gain flattening D electric output to optical modulator 2R or 3R ? modulator unit D D D D D D D D D D D resistor I0 I1 Ix 3 0 1 2 4 5 15 # PMT’s ToT signal PMT 5 ToT signal PMT 2 identifier Example 16 PMT’s and 4 identifiers => 20 data bits. Optical trigger repetition rate: 1,6 nsec <=> 3,2 nsec 80 <=> 160 psec sample pulse width. If “D” delay 100 psec then the system adapts to10Gb/s optical transmission technology. I0 I1 Ix 0 1 2 3 4 5 15 serialized output after optical trigger 1,6 nsec <=> 3,2 nsec Jelle Hogenbirk et.al.

6. Recovering PMT’s Time over Threshold on shore Sub-sea Late hit? Hit 1 PMT 2 Hit 2 PMT 5 Readout pulses x+ .. Original PMT Pulse ToT 1 Readout pulses the “heartbeats” 2 x + .. 1 2 3 4 5 6 7 8 3 2 nsec 2 nsec 4 Related pulses 5 # PMT 1 2 3 4 5 Shore 100 psec Recovering PMT’s ToT Jelle Hogenbirk et.al.

7. Signal path and loop-timing scheme Shore Optical Amplifiers Single shared feed fibre with DWDM seed plus clock / framing on l1 Gated Semicondutor Optical Amplifier for Signal propagation time measurements 10% Burst-mode Optical receiver Circulator Power splitters to feed up to 100 units 20% PMT electronics tap lN+l(N+1) 30% 10% l2+3 l1 Reflective Modulator 2x(N+1) AWG DWDM OPTICAL MODULE Modulator (gate) Generating CW + heartbeat signal On one fiber to/from OM Mirror (for 100km loop timing) To Gated SOA Optical receiver AWG FSR CDR & controller 2.0 km of single fiber CW seed + heartbeat and in opposite direction modulated signal back to shore l Sub-sea l(N+1) l1 7 Jelle Hogenbirk et.al.

8. Measurement Results Backscatter impact on 10G/s 2km SMF28 in the R-EAM link Laser Santec 1558.7nm (back-to-back) Jelle Hogenbirk et.al.

9. 5 Detection Unit options sub-sea network OM1 OM1 1 fibre to each OM 1 fibre to each OM 20 20 20ch cyclic AWGs Single fibre interface to each string 20-fibre ribbon connection to string DU1 2 3 4 5 DU1 2 3 4 5 100ch AWG WDM ADMs Strings of 20 OMs over 20 floors To JB To JB May be in JB or DU (b) Multiple AWGs* + ADM** single-fibre connectors (a) Single AWG* ribbon connectors *AWG (Arrayed Wave Guide) is the applied hardware for DWDM (Dense Wavelength Division Multiplexing) technology **ADM (Add Drop Multiplexer) take out # wavelengths from a wavelength comb on a fibre and put them back on after external access Jelle Hogenbirk et.al.

10. Test bench SPARK Sophisticated Photonic Architecture Readout for KM3Net laboratory optical network test setup for 10Gb/s clk AWG driver data cw ch 17 17 18 19 R-EAM 17 18 19 clk driver to sub-sea from shore R-EAM DWDM combiner data DWDM cw ch 18 R-EAM clk R-EAM driver data cw tun SOA FPGA FPGA clk receiver data PIN sub-clk clk receiver data PIN from sub-sea to shore DWDM sub-clk 20 km fiber (without optical amplifiers) And tested at 100 km (with optical amplifiers) Shore Sub-sea Optical connector for flexible use of SPARK Jelle Hogenbirk et.al.

11. Realized SPARK setup for 10Gb/s Jelle Hogenbirk et.al.

12. Results pulse Transmission over 10 km jitter mainly from P-N change over in the electronic circuitry Refer to next presentation of Peter Jansweijer 48.80 ps Jelle Hogenbirk et.al.

13. 10 Gb/s Eye Pattern Received signal after a 10 km connection at receiver output BER is Bit Error Rate The more open “eye” The better SNR(Signal to Noise Ratio) BER figure shows Signal Quality 72.4 mV/div Clock Rec: 10,3125 Gb/s Time 16.2 ps/div Trig: Pattern 5.1 mV LBW 4.13 MHz Delay 40.1552 ns Bit 113 Jelle Hogenbirk et.al.

14. Node Interface Kit end-node shore “Heartbeat” with embedded SC Mem Continuous wave laser Optical Network PMT data GbE DM laser FPGA FPGA R-EAM TTC PIN CW laser Gen. I/O 311 Mhz clock 311 Mhz clock PIN (transparent for the data transmission format) e.g. OM SPARK Light 10 Gb/s GPS Receiver and reference clock up to 12x 10 Gb/s including a basic firmware for the 10 gb/s network interface outside world to the optical network Evaluation board Altera Stratix IV GT determining the functionality in the end-node Typ. power Stratix GT SERDES: 171 mW at 10.3 Gbps Altera Stratix IV GT sampling now Xilinx Virtex 6 HXT sampling Q1 2010 Jelle Hogenbirk et.al.

15. Node Interface Kit (depicted 1 channel) end-node shore “Heartbeat” with embedded SC Continuous wave laser Mem PMT data GbE DM laser FPGA FPGA R-EAM DWDM DWDM TTC PIN CW laser Gen. I/O 311 Mhz clock 311 Mhz clock PIN DWDM e.g. OM 10 Gb/s GPS Receiver and reference clock up to 12x 10 Gb/s SPARK Evaluation board Altera Stratix IV GT PMT readout, TTC and general I/O Functionality hard/firmware to be implemented by the client Typ. power Stratix GT SERDES: 171 mW at 10.3 Gbps Altera Stratix IV GT sampling now Xilinx Virtex 6 HXT sampling Q1 2010 Jelle Hogenbirk et.al.

16. Example of NIK Node implementation for the Multiple PMT Optical Module 10 - 14V 1V8, 3V3, 5V POWER Board SPARK Control 31 LVDS signals 622Mbps Octopus Board Optical Network PIN CDR FPGA AlteraStratix IV PMT’s PMT LVDS signals I2C Bus R-EAM R-EAM driver PMT control 10Gbps Spare I/O I2C SPI 3D COMPASS HMC5843 ADC LED Beacon • Sensors: • Temperature? • Voltage? • Water? All I/O 3v3 or 1v8 or LVDS Acoustic Sensor Mezzanine Boards Jelle Hogenbirk et.al.

17. A photonic network for data acquisition systems for deep-sea neutrino telescopes Jelle Hogenbirk et.al.

18. Thank you and remember Expertise is the last thing you need for an animated discussion Jelle Hogenbirk et.al.