Filiberto, Sheila
This afternoon Filiberto swapped the connections on the PZT and oven translation stage DB9 connector on the OPO base plate. This went well, the pin out of the connector is the same as shown in the O3 squeezer wiring (v7) and the O4 wiring (v10) with the positive PZT lead indicated by the black dot on the PZT to pin 8, the other lead on pin3 (M2 is labeled as Piezo 1 in the drawings). The leads on the new PZT are a bit long, so the cable routing is a little creative, I will attach a photo.
While Filiberto was in the lab, he checked the pin out of the class A cable D1700438. (This cable is labeled as D1700238 in the v7 drawings and I have sometimes labeled it that way) The pin out is in agreement with the drawing. A problem with this cable would have been one possible explanation for why we get a normal range from the PZTs with the set up in the optics lab, but only got ~2 FSRs for 100V in the chamber.
I applied 0-150V to this PZT this morning, and I saw 3 full FSRs scanning with 1064nm, which could probably have been 4 FSRs if I had adjusted the offset.
I'm confident that the polarity is correct, both because Filiberto was careful to check the pins and because the cavity is poorly aligned so I can see the first order mode in the same position relative to the 00 mode as when scanning the M4 PZT. (In other words, the modes appear in the same order when scanning both PZTs, meaning that both PZTs are traveling in the same direction for the same applied voltage.)
This PZT is http://www.noliac.com/products/actuators/ring-actuators/show/nac2121/ which I believe is the same PZT as used for the other mirrors. The max free stroke is 3.3um for 200V max applied voltage, so we should expect to see ~4.5 FSRs when scanning with 1064. This seems to be close to what we are seeing, I am wondering if this is the same model PZT as the one on M4.
Yes, M2 and M4 use the same model of PZT.