I took the liberty of making my own plot. This was both in the interest of time and also to better illustrate how the plot should be made by example:
Also, some general plotting tips:
Try to let this stuff soak in, as we'll probably have to make this whole measurement again. Next time, you will plot it!
Another thing: our whole noise budget will get a little more complicated once we add in the lockin, but this analysis of the front-end (the very place where physics meets measurement apparatus) is extremely important.
The last post we discussed the noise measurements with a noticeable peak around the 50kHz. This time, we've set the preamp gain to 500 and retook the measurements. The attached image shows the result of said measurements.
One thing we noticed is that the photodetector noise is roughly two orders of magnitude smaller than our best estimates for this. Zach thinks it's not real, I think it's pretty awesome. Here some explanations of the measurements.
I've also noticed that the plot doesn't make complete sense to me. For example, the noise floor of PD1 seems to be higher than PD1 itself - but maybe Zach can re-explain to me the difference between fixed range and auto range here.
For lazy people, I've reattached the experimental set up and noise calculations.