1. Photodiodes Ingle and Crouch, Spectrochemical Analysis Photons incident on the depletion layer induce a current. In most cases, best response in the NIR. Response is linear over 6 – 7 orders of incident radiant power

2. Spectral Response of Photodiodes Shinya Inoue and Kenneth Spring, Video Microscopy, Plenum Press, New York, 1997.

3. Avalanche Photodiode http://micro.magnet.fsu.edu/primer/java/digitalimaging/avalanche/index.html Hamamatsu Catalog

4. Photodiode Arrays (PDA or DAD) Douglas A. Skoog and James J. Leary, Principles of Instrumental Analysis, Saunders College Publishing, Fort Worth, 1992. Simultaneous detection in a spectrophotometer.

5. Charge Coupled Device (CCD) Ingle and Crouch, Spectrochemical Analysis www.piacton.com

6. CCD Architecture http://micro.magnet.fsu.edu/primer/digitalimaging/concepts/ccdanatomy.html and Bryce Marquis (Haynes Lab) Image Area serial register amplifier SiO 2 backing Pixel Array

7. CCD Architecture Bryce Marquis (Haynes Lab) One pixel “Channel Stops” form horizontal pixel boundaries 3 electrodes form vertical pixel boundaries Top View Cross section Insulating oxide n-type silicon p-type silicon Electrode

8. Charge Generation/Collection N-type P-type -V +V Incident photons excite electron-hole pairs, electrons gather in potential wells in each pixel -V +V

9. CCD Rain Bucket Analogy Shinya Inoue and Kenneth Spring, Video Microscopy, Plenum Press, New York, 1997. 1. Generation 2. Collection 3. Transfer 4. Measurement

10. Charge Generation/Collection N-type P-type -V +V N-type silica is doped with pentavalent species = excess electrons P-type is doped with trivalent species = excess holes -V +V Potential Well One Pixel

11. 1 2 3 +5V 0V -5V +5V 0V -5V +5V 0V -5V Time-slice shown in diagram 1 2 3 Charge Transfer Every third electrode is coupled, charge packets are walked towards serial registry to serial registry http://spiff.rit.edu/classes/phys445/lectures/ccd1/ccd1.html

12. 1 2 3 +5V 0V -5V +5V 0V -5V +5V 0V -5V 1 2 3http://spiff.rit.edu/classes/phys445/lectures/ccd1/ccd1.html

13. 1 2 3 +5V 0V -5V +5V 0V -5V +5V 0V -5V 1 2 3http://spiff.rit.edu/classes/phys445/lectures/ccd1/ccd1.html

14. 1 2 3 +5V 0V -5V +5V 0V -5V +5V 0V -5V 1 2 3http://spiff.rit.edu/classes/phys445/lectures/ccd1/ccd1.html

15. 1 2 3 +5V 0V -5V +5V 0V -5V +5V 0V -5V 1 2 3http://spiff.rit.edu/classes/phys445/lectures/ccd1/ccd1.html

16. 1 2 3 +5V 0V -5V +5V 0V -5V +5V 0V -5V 1 2 3http://spiff.rit.edu/classes/phys445/lectures/ccd1/ccd1.html

17. 1 2 3 +5V 0V -5V +5V 0V -5V +5V 0V -5V 1 2 3http://spiff.rit.edu/classes/phys445/lectures/ccd1/ccd1.html

18. Charge Transportation Pixels at end of the array dump charge into serial register Serial register walks charge packets to amplifier, where it is measured. amplifier

19. Quantum Efficiency www.piacton.com

20. Noise Sources in CCD Shot Noise –Statistical variation of signal over time Increases with the square of the intensity Dark Signal Noise –Caused by thermal liberation of electrons Strongly coupled to temperature Readout Noise –Summation of noise associated with amplification of signal, and conversion from analogue to digital Increases with the processing speed

21. Other Issues: Bad Pixels Hot Pixels –Increased charge accumulation due to variations in chip surface. Dead Pixels –Defective pixels that do not respond. Increasing hot pixels

22. Other Issues: Blooming

23. Other Issues: Cosmic Rays * indicates cosmic rays

24. Other Issues: Etaloning Etaloning www.piacton.com

25. Other Features: Binning On Chip Pixel Binning –Increases S/N Shot noise decrease –Increased speed –Less storage space needed –Decreases resolution http://micro.magnet.fsu.edu/primer/digitalimaging/concepts/binning.html

26. Are you getting the concept? List the advantages and disadvantages of using each of the discussed detectors to achieve single molecule detection.