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Responsivity Vs sensitivity

  1. Aug 4, 2010 #1
    Hello frnds!

    Nice to meet you all here.

    Can anybody help me in understanding the exact differences between responsivity and sessitivity of a photodiode or photodetector?
  2. jcsd
  3. Aug 4, 2010 #2
    Responsivity measures the amount of output swing produced by a specified input swing. For example, if you had a photodetector that produced a voltage output proportional to incident power, responsivity would be measured in V/W.

    However, note that this is not enough information to tell you how "sensitive" a detector truly is, because you can always take an electrical signal and boost it with an low-noise amplifier. If you did this, your responsivity would go up, but the noise intrinsic to the detector would also be boosted (i.e., your signal-to-noise ratio would remain the same). There are multiple definitions for sensitivity; one common one is the noise-equivalent power, which is the amount of power required on the photodetector to produce a signal-to-noise ratio of 1.
  4. Aug 5, 2010 #3
    Thank you Manchot. :)
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