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?

 

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.