I have a laser that I modulate at some frequency, typically 1250 Hz. I have a sensor that tracks what happens inside a reactor when it's illuminated. I am doing Fourier analysis on both the laser modulation signal and the sensor, and extracting the components at 1250 Hz, forming a time series of phases.
I was playing around with these phase relationships in Excel and I came up with this plot. Laser is the x-axis, sensor is the y-axis. I'm trying to think back to college because I swear I've seen something like this before, but would appreciate any commentary!