2.  The CCD sensor was invented in 1969 by Willard Boyle and George E. Smith of AT&T Bell Labs.  Originally intended as a memory device

3.  Pixel: Picture Element  CCD: Charge-Coupled Device  CMOS: Complimentary Metal-Oxide Semiconductor  Panchromatic: Sensitivity to a wide range of wavelengths of light.

4. 1. Photoelectric effect creates an electron-hole pair when light impinges upon a semiconductor 2. Each pixel accumulates a charge 3. When sampled, the “bucket of charge” for each pixel is transported off-chip to on off-chip amplifier 4. A capacitor is used to convert the charge to a voltage. V = q/C

8.  Used largely in military and scientific applications.  The image-intensifier is added to a CCD to create an intensified CCD.  Provides single-photon sensitivity  Also enables extremely short exposure times. (down to 200ps)  It reduces the shortcomings of a bare CCD

9. PhotocathodeMicro-channel Plate (MCP)Phosphor Screen CBA A: 200V Gating Voltage (variable) B: 1000V Micro-channel plate C: 6kV acceleration voltage A > 0: Shutter is open (gated) A < 0: Shutter is closed

10. A: 200V Gating Voltage (variable) B: 1000V Micro-channel plate C: 6kV acceleration voltage A > 0: Shutter is open (gated) A < 0: Shutter is closed PhotocathodeMicro-channel Plate (MCP)Phosphor Screen CBA e-e- e - s (1000x)

11. PhotocathodeMicro-channel Plate (MCP)Phosphor Screen

12.  Is officially defined as the percentage of photons hitting a surface that will produce electron-hole pairs › Regular photographic film is about 10% › Human Eye is about 3% › CCDs can have a QE of more than 90% at some wavelengths  Useful for rating solar cells  Doesn’t account for unwanted recombination in material

13. Quantum Efficiency of CCD used in Hubble Space Telescope’s Wide-Field and Planetary Camera 2

14.  When charges are shifted from pixel to pixel it is the loss associated with each shift. A value of 0.999 is actually bad!  Most CCDs use 2000-4000 shifts to read a single pixel out.

15.  Thermal excitations can excite electrons into the conduction band  This is the reason that most CCDs require extensive cooling (-90 to -40 °C)

16.  Electronic amplifiers are not perfect and introduce their own noise.  This determines the “noise floor” of the CCD. It sets the limitation of how faint of an object a CCD can see.

17.  Optically insensitive structures for each pixel (absorption loss)  Natural reflection of certain wavelengths (reflection loss)  Very long and very short wavelengths pass straight through sensor without generating an electron (transmission loss)

18.  CCDs are simple application of the photoelectric effect  Intensified CCDs improve the light sensitivity of a bare CCD  Intensified CCDs are used in military and scientific application (mostly astronomy)

19.  http://www.asiimaging.com/pdfs/Comparison_of_CCD_Cameras_to_an_Ide al_Camera.pdf http://www.asiimaging.com/pdfs/Comparison_of_CCD_Cameras_to_an_Ide al_Camera.pdf  http://www.andor.com/learn/digital_cameras/?docid=326 http://www.andor.com/learn/digital_cameras/?docid=326  http://www.dalsa.com/dc/documents/Image_Sensor_Architecture_Whitepa per_Digital_Cinema_00218-00_03-70.pdf http://www.dalsa.com/dc/documents/Image_Sensor_Architecture_Whitepa per_Digital_Cinema_00218-00_03-70.pdf  http://www.dalsa.com/markets/ccd_vs_cmos.asp http://www.dalsa.com/markets/ccd_vs_cmos.asp  http://www.iccd-camera.com/technology_main.html http://www.iccd-camera.com/technology_main.html  http://en.wikipedia.org/wiki/Quantum_efficiency http://en.wikipedia.org/wiki/Quantum_efficiency  http://wfc3.gsfc.nasa.gov/MARCONI/machines-see.html http://wfc3.gsfc.nasa.gov/MARCONI/machines-see.html