Ronic just suceeded in obtaining a reasonably good lock on the cavity. Air flow is switched off.

We stopped all movements (closed loop, click STOP in the PTC interface) and saw immediately a fair but not excellent lock.

We then switched off the smaract motors and the obtained lock was good. Switching on again the smaract means tthat the references are lost.

We futher saw a drift of the locking point, probalby suggetsing that the thermal load in the cavity slightly changed after switching off the motors.

We then added the second 1GHz BW EOM to add sidebands thanks to the MARCONI RF generator. We observed that the FSR is aroung 867.6MHz (in air). We then looked at the points where the transmission signal related to the sideband is halved. We observed that the corresponding frequencies are 867.296 and 867.776MHz. the corresponding FWHM of about 500kHz corresponds approximately to a 2000 finesse.

Picture color code:
TRANS : Green
REFLECT : Yellow
PZT : Blue