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Circuit review: Transimpedance amplifier to measure shot noise in a photodiode

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Kleinstein:
Besides the noise if the photdiode there is also noise from the light source. In many cases the shot noise is actually more from the light source and not the photo-diode.
There are special low noise laser sources that in combination with a reasonable good detector (good quatum efficiency) can get well below the classical shot noise limit. So the photodiodes produce less shot noise than one may think and the classical equation gives.  AFAIR there is an additional factor of  (1- quantum efficiency) for coherent light that is often ignored.

Marco:

--- Quote from: Someone on November 28, 2022, 09:47:22 pm ---Shot noise can be dominant at any bandwidth

--- End quote ---

Dominant, but not very interesting. With laser light the shot noise tells you something, with current through a PN junction what's really there to measure? Yep it's shot noise?

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