[Daniel, Torey]

We took off mirror 1 (the input coupler and located the beam that goes through the cavity with an iris. We then put m1 back on and aligned the promply reflected beam through the iris using a power meter. We put this beam through an OD 2 and OD 0.4 filters because the newport 1811-FS photodiode has a max power of 55 uW and our input power is 13 mW. We also put the beam through a 25.4 mm focal length lens because the photodiode is so small.

While driving the piezo, we did not see a refl dip. We ensured all of the electrical connections were good and we could hear the piezo being driven at 1 kHz. Thus, the piezo is working.

We are concerned that the small photodiode prevents us from seeing the refl dip. We plan on adding a mirror (or beam splitter) before the OD filters and using a Thorlabs photodiode, which has a much larger sensor.