The cavity still isn't locking properly, so we're sweeping the cavity to have a look at the error signal. The first picture is with everything setup the same way as when we walked in today, and for the second we adjusted the length of a BNC cable and messed with the phase knob on the PDH box to get rid of the DC offset on the error signal.

Blue is the PDH error signal, Yellow is the reflection PD signal, and pink is the waveform we're using to sweep the cavity.