1. Optoelectronics & Microsystems Lab Politecnico di Milano, Dip. Elettronica e Informazione, Milano, Italy

2. S. Cova et al., 2004 POLIMI - Politecnico di Milano, DEI Optoelectronics & Microsystems Lab STAFF COVA, S. Full Professor GHIONI, M. Full Professor ZAPPA, F. Associate Professor GIUDICE, A. Post-Doc Research Associate RECH, I. Post-Doc Research Associate LABANCA, I. Research Associate GALLIVANONI, A.Research Associate TISA, S.Ph.D. Student RESTELLI, A. Ph.D. Student TOSI, A.Ph.D. Student GULINATTI, A. Ph.D. Student

3. S. Cova et al., 2004 POLIMI - Politecnico di Milano, DEI Optoelectronics & Microsystems Lab Core Know-How Microelectronic Detectors and Circuits Measurement Techniques and Instrumentation for detecting and measuring optical signals with ultra-high sensitivity and picosecond resolution

4. S. Cova et al., 2004 POLIMI - Politecnico di Milano, DEI Optoelectronics & Microsystems Lab Bias: well ABOVE breakdown Geiger-mode: its a TRIGGER device!! Gain: meaningless... or infinite !! Bias: slightly BELOW breakdown Linear-mode: its an AMPLIFIER Gain: limited < 1000 A valanche P hoto D iode S ingle- P hoton A valanche D iode APD SPAD

5. S. Cova et al., 2004 POLIMI - Politecnico di Milano, DEI Optoelectronics & Microsystems Lab Thin Si SPAD Thick Si SPAD Planar structure typical active region: 20 m diameter 1 m thick Reach-Trough structure typical active region: 200 m diameter 30 m thick

6. S. Cova et al., 2004 POLIMI - Politecnico di Milano, DEI Optoelectronics & Microsystems Lab Thin Si SPADs Thick Si SPADs Good QE and low noise Picosecond timing Low voltage : 15 to 40V Low power : cooling not necessary Standard Si substrate Planar fabrication process COMPATIBLE with array detector and ICs (integrated circuits) Robust and rugged Low-cost NO COMMERCIAL SOURCE TODAY Very good QE and low noise Sub-nanosecond timing High voltage : 300 to 400V High dissipation : Peltier cooler required Ultra-pure high-resistivity Si substrate Dedicated fabrication process NOT COMPATIBLE with array detector and ICs Delicate and degradable Very expensive SINGLE COMMERCIAL SOURCE

7. S. Cova et al., 2004 POLIMI - Politecnico di Milano, DEI Optoelectronics & Microsystems Lab Passive quenching is simple... Current Pulses Diode Voltage … but suffers from long, not well defined deadtime low max counting rate < 100kc/s photon timing spread et al

8. S. Cova et al., 2004 POLIMI - Politecnico di Milano, DEI Optoelectronics & Microsystems Lab Activequenching…. Active quenching…....provides: short, well-defined deadtime high counting rate > 1 Mc/s good photon timing standard logic output Output Pulses P.Antognetti, S.Cova, A.Longoni IEEE Ispra Nucl.El.Symp. (1975) Euratom Publ. EUR 537e

9. S. Cova et al., 2004 POLIMI - Politecnico di Milano, DEI Optoelectronics & Microsystems Lab Earlier modules in the 80s Compact modules in the 90s Integrated AQC today AQC evolution

10. S. Cova et al., 2004 POLIMI - Politecnico di Milano, DEI Optoelectronics & Microsystems Lab iAQC - Integrated Active Quenching Circuit F.Zappa, S.Cova, M.Ghioni, Monolithic circuit of active quenching and active reset for avalanche photodiodes, US Patent 6,541,752 B2, date April 1,2003 (priority date March 9, 2000); European patent application n. 01200852.2-2217, fil. March 6, 2001. F. Zappa, A. Lotito, A. C. Giudice, S. Cova, and M. Ghioni, IEEE J. Solid-State Circuits, 38, 1298-1301 (2003). Input sensing and quenching stage

11. S. Cova et al., 2004 POLIMI - Politecnico di Milano, DEI Optoelectronics & Microsystems Lab iAQC - Integrated Active Quenching Circuit CMOS design +V HIGH +5V IN GATE GND WIDTH OUT

12. S. Cova et al., 2004 POLIMI - Politecnico di Milano, DEI Optoelectronics & Microsystems Lab iAQC - Integrated Active Quenching Circuit Practical advantages Miniaturization mini-module detectors Low-Power Consumption portable modules Ruggedness and Reliability Plus improved performance Reduced Capacitance Improved Photon Timing Reduced Avalanche charge Reduced Afterpulsing Reduced Photoemission reduced crosstalk in arrays

13. S. Cova et al., 2004 POLIMI - Politecnico di Milano, DEI Optoelectronics & Microsystems Lab QE comparison

14. S. Cova et al., 2004 POLIMI - Politecnico di Milano, DEI Optoelectronics & Microsystems Lab Photon Timing comparison Planar thin Si-SPAD PerkinElmer SPCM (SLIK TM diode)