Before putting the filter cavity input mirror into vacuum, we checked the green beam at different point of the system. 

Filter cavity end mirror: green arrived at the baffle below the mirror, horizontal position seems to be ok.

Filter cavity input mirror: the cameras installed on the viewports of the input mirror didn't give a clear view of the beam position, we roughly put the beam at the center by changing the offset on the GR_M5 and GR_M7 mirrors.

SQB2_M1: we started to search the reflection from the input mirror at SQB2 with the mirror free swinging. We first closed the TY loop of the oplev in a setpoint where the reflection beam is reaching the M1 mirror. Then we observed the beam was moving vertically back and forth and can reach roughly the mirror center when it was swinging between 0 and 5000urad, so we tried to close the TX loop with setpoint of 0. In this case, the reflection is quite close to the injection beam on M1(see attached picture taken from the viewport of SQB2). And we also saw the reflection beam on GR_M6 of EQB1.

Note that due to the venting of FCIM, the SQB2 bench vertical position is much lower than the nominal value. So we are going to realign once the FCIM is completely under vacuum.