Lot of low frequency noise --- problem with PDs?
At that separation you should have an obvious heart rate signal in your recorded signal. What is the optical power you have from the LED?
Thank you for taking the time to respond to my post!
I am sorry the figures are not visible, I have added them to a document that is viewable here: https://docs.google.com/document/d/1d_MUGyrnxGscwmeS_NNY4RnBa_t7kwH5AsOUywFjy5w/edit?usp=sharing
The plots in this are from a 735 nm LED that is continuously on.
The PD reading varies depending on the filter cutoff. I am using an Everlight Electronics's 67-21S/NFR2C-P2050A3B21522Z6/2T
which as radiometric power varying from 15-50 mW.