O4 Commissioning Task List

This is a list of things to do for each commissioning stage for O4.

Each stage include ASC.

Preparations

Tune f1, f2, f3 frequencies to IMC FSR
Replace all the in-vac steering mirrors and pick-off mirrors to proper ones JGW-T2112592
Replace all the beam splitters in in-air optical tables to non-polarizing beam splitters JGW-D2112956
- This is necessary to estimate the polarization content of the interferometer correctly (without too much confusion)
Install polarization optics to backward POP or POS, and TRY and TRY.
- This is necessary to estimate the arm cavity round-trip loss correctly JGW-T2011633
Check actuation efficiencies of IMC mirrors, frequency actuation efficiencies of PSL.
Install picomotor+PZT steering mirrors for POP green and POS green.
Install coil driver switch for ETMs (and ITMs?).
- High power for lock acquisition, low power for low noise mode.
Install picomotors to center the beam on oplev QPDs and ASC QPDs.
Inject a fake RF signal to PDA1 to reproduce the spurious coupling around the REFL table and ALS racks
- klogs 10958,10959, 11014, 11315, 12382, 12392,
- Perhaps illuminating PDA1 by intensity modulated light maybe interesting.
- Insert Baluns as necessary.

Measure the finesse at room temperature and at cryogenic temperatures, for both 1064 nm and 532 nm.
Measure the round-trip loss by taking into account the effect of birefringence correctly.
- Measure the beam spot position dependence.
Measure the amount of POP/POS p-pol when the arm is locked and unlocked.
Measure the mode-matching for both 1064 nm and 532 nm.
Tune the Gouy phase separation between two QPDs at REFL/AS/TRX.
- Make sure all the signals are in in-phase.
Measure the alignment sensing matrix at REFL/AS/TRX, for ITM and ETM.
- Try closing ASC loops.
Measure modulation depths for f1, f2 and f3.
Check ITM and ETM actuation efficiencies.
Make a power budget of each ISC detection port.
Refining the automation -- mainly for the successive full ifo initial alignment.
Leave a record on the demod phases -- for repeating the Schnup asymmetry measurement.
Establish IR/Green co-alignment procedure -- for full ifo initial alignment.
Could we check out the common mode servo board at this point?

Check BS actuation efficiency.
Check out the LSC optical gain. Should be easy enough to doublecheck.
Measure, again, the contrast defect.
Record typical Mich length noise.
Close the ASC loops -- mainly for the purpose of the initial alignment automation.
Refine the automation.

Measure PRY length and PRX length.
- Previous methods give inconsistent results and also not compatible with Schnupp asymmetry measurements.
Tune IMC length to PRC length (and re-tune sideband frequencies).
Check actuation efficiency of PR mirrors.
Measure PRC Gouy phase.
Close the ASC loops.
Refine the automation.
Check out the power build up in the carrier-locked and side-band locked conditions
Correlation measurement of p/s-pol sloshing (https://klog.icrr.u-tokyo.ac.jp/osl/?r=9333) against angular fluctuations or whatever.
Identification of any drifty suspensions as the carrier is locked -- to support the coming full lock operation.
Tune up the triggers and filter shapes for fast lock acquisition.

Measure power recycling gains for carrier and sidebands, with and without SRC.
Measure length sensing matrix.
- Both for 1f and 3f signals.
- Optimize the modulation depths if necessary for sufficient signal-to-noise ratio for 3f signals.
Measure power at each ISC detection port when DRMI is locked.
Tune the Gouy phase separation between two QPDs at POP.
Measure the alignment sensing matrix at REFL/POP/AS.
- Try closing ASC loops.
- Most notably the f1-f2 WFSs at AS
Examine the mode-hop criteria (https://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=12213)
- Which mirror affects most and how much angular motions are tolerable?
- Is the SRC Gouy phase large enough?
Refine automation.

Measure length sensing matrix.
Measure power at each ISC detection port when FPMI is locked.
Measure the alignment sensing matrix at REFL/POP/AS/TRX/TRY.
- Try closing ASC loops.
- Test out the radiation pressure basis actuation scheme
Do some noise hunting at low frequencies and VIS commissioning with FPMI
- Perhaps interesting to lock OMC to check out the freq/int noise couplings to AS port.
- Also, rf phase and amp noises.
OMC ASC commissioning?

* Repeat the same measurements as described in

Measure length sensing matrix.
Measure power recycling gains for carrier and sidebands
Measure power at each ISC detection port when PRFPMI is locked.
Measure the alignment sensing matrix at REFL/POP/AS/TRX/TRY.
- Try closing ASC loops.
Refine automation.
- Review/refine the O3GK lock acquisition process.

Measure length sensing matrix.
Measure power recycling gains for carrier and sidebands
Measure the cavity pole
Measure power at each ISC detection port when PRFPMI is locked.
Measure the alignment sensing matrix at REFL/POP/AS/TRX/TRY.
- Try closing ASC loops.