Lock in Amplifier + Shot Noise ?

Thread Starter

SteTrat

Joined Jan 6, 2016
2
Hi,

as a chemist i am dealing in the near future with some shot noise measurments.
I am wondering if it would be possible to detect expected shot noise buried in noise, with the lock in technique?

Concerning the basics: i know that DC signals can be measured by chopping (multiplication with a square wave), and that general modulated signals (like sine waves) can be detected.

But random shot signals, like a little burst?
 

crutschow

Joined Mar 14, 2008
29,825
I don't see how you could differentiate random shot noise from other random noise.
The lock-in technique allows the detection of coherent signals, not random noise.
 
With the lock-in technique, you have to know when the signal is present. The present and non-present portion is periodic.
Sine is easy to deal with. With the DSP lockins from SRS, you can do better. Mechanically chopping usually results in a trapezoid waveform.
 
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