1. Creating a System to Test Single Photon Avalanche Diodes Alex Chan Young Scholars Program Farragut High School July, 16,2014 Knoxville, Tennessee

2. My Goals Create a Printed Circuit Board to test Single Photon Avalanche Diodes Automate the data using MATLAB

3. Overview What are Single Photon Avalanche Diodes (SPADs) What are Printed Circuit Boards Oscilloscope/Sourcemeter MATLAB data acquisition How it all ties together 3

4. Single Photon Avalanche Diodes SPADs are amplifiers used to detect weak optical signals Incoming photons trigger avalanche currents which are detected SPADs must be “quenched” for repeated use (usually with a resistor) Internal noise is measured by dark count rate 4

5. What are SPADs used for? Any sensitive vision systems  Medical imaging  Astronomy  Astrophysics 5

6. Printed Circuit Boards Thin Boards made of insulating material Etched with pathways for electricity to travel Components can be added to create circuits 6 Etched Wire Resistors Chip Holder

7. Advantages and Disadvantages of PCBs AdvantagesDisadvantages ReplaceableHard to repair Mass ProducibleMust be redesigned Reliable Compact 7

8. Where can you find PCBs? 8

9. Development of a Printed Circuit Board Using Eagle PCB, a printed circuit board was developed in which any DIP40 pin packaged chip could be tested 9

10. Blinky Board 10

11. My Board 11

14. Oscilloscope and Sourcemeter 14

15. MATLAB goals Automate the data coming from the oscilloscope and sourcemeter 15

16. Altering the base code from Oscilloscope and Sourcemeter and tested using a 100kΩ resistor 16

17. 17

18. R = V/I

19. Putting it all together 19 Printed Circuit Board Used to test SPAD chip Oscilloscope and Sourcemeter Measure the voltage and current output from SPAD MATLAB Automates the incoming data

20. Results Optical Testing of the SPAD 20

21. Results (continued) Electrical Testing of the SPAD 21

22. Conclusion The process for testing Single Photon Avalanche Diodes is now automated making it faster and more efficient 22

23. Acknowledgements This work was supported primarily by the Engineering Research Center Program of the National Science Foundation and the Department of Energy under NSF Award Number EEC-1041877 and the CURENT Industry Partnership Program. Special thanks to my mentors Geneva and Habib and Dr. McFarlane 23