WHAM6 OPO/SQZ cables on C1 Adapter complete

Under WP 7348, last week, Corey and Nico help connect these cables to the C1 (top of chamber) conflat feedthrus.  The cables are now available for routing onto the table to the OPO & SQZ.  They are hanging on the SW side of the ISI.  They are labeled with ClassB metal tags and these should be removed after connecting.  They are labeled just as the In-Air side of the Feedthru is labeled, see attached photo and can be determined from D1300122 Sheet 8.  For example, C1-2C1 is the ZM1 Tip/Tilt BOSEMs.

The feedthru has been clamped metal to metal on the air side.  It has not been vacuum tested.  WP 7348 is closed.  WP 7341 (Septum Cover Install) remains open.

PSL Weekly Report - 10 Day Trends FAMIS #6188

PSL tripped over the weekend. Maik and Matt here to do 70W work. Trends look messy due to trips and chiller work. Too much to narrate. See you on the other side.

Shift Summary - Day

14:45 Chris to end stations for engine hoist moves

15:31Mark to EX to move engine hoist

16:00 Kyle at MY

16:30 Betsy into LVEA (biergarten) to have a look

16:31 Kyle back; Chris back and into LVEA

16:42 Cintas on site

16:42 Kyle to EY to recover moisture meter(s)

16:59 Sheila going into the optics lab

17:00 Chandra at EY with MCE

17:03 Chris and Mark to MY

17:07 Betsy out

17:08 Jeff B into cleaning area and possibly into LVEA

17:16 Kyle and Gerardo out to LVEA to begin CS venting process (WP 7538)

17:52 Norco on site with LN2 delivery to MY dewer

17:55 Hugh out to HAM6‌ for cleanup and looking for Viton

17:59 2nd Norco delivery on site heading to the other MY dewer

18:03 Fil heading into LVEA for cabling

Kyle and Gerardo out

18:09 Portable toilet service on site

18:10 Jenne, Tvo ad Evan to LVEA - taking posed photos

18:11 Jeff B out

18:11 Multiple WD tripped: BS, ITMX, ITMY(St1&2 all), HAMs 2,3,4,5

18:20 Corey out to Optics lab and then out to LVEA (ISCT1)

18:21 Jenne, Tvo and Evan back

18:55 reset all aforementioned WD trips

19:01 Jeff B to out-buildings to check dust monitors

19:05 all aforementioned WDs . re-tripped. (probably due to work being done with electronics)Jim reported that damping loops are still on.

19:48 Corey out

20:44 MCE out

21:01 Sheila and Terry out for lunch

13:23 Hugh out to HAM6 to torque bolts

21:29 Peter headed to the PSL enclosure to retrieve equipment

21:41 Gerardo to LVEA to retrieve humidty meters to bring to EX for tomorrow's vent

21:42 Betsy out to LVEAto start prep for the in-vac cable repair at BSC1

22:12 Hugh back from HAM6

22:13 Betsy back from BSC1

22:20 Jeff B

22:30 Hugh out to LVEA

22:42 Sheila back out to Optics lab

22:43 Betsy out to LVEA

22:45 Travis out to EY

22:48 TJ out of LVEA

22:54 Hugh out

23:04 TJ ad Alvaro out to optics lab

23:19 Gerardo back

23:21 Betsy and Gerardo out to LVEA/BSC1

Monthly Dust Monitor Vacuum Pump Checks (FAMIS #7522)

 Check all the dust monitor vacuum pumps. Adjust bypass, as necessary, for correct flow rate, All temps are within range. End-Y temp are a bit high due to the high room air temps from the main vacuum pumps.

DMT test box patched and rebooted

The h1dmt3 DMT box at LHO has been patched via yum update and rebooted. This is the DMT test box, and this update should have no impact on the control room.

EY is now LASER HAZARD

Rick, Travis

Some temporary Pcal work is happening. Transition back to SAFE when work is complete.

Conlog crashed, restarted, updated channel names

Appears to have crashed Saturday on an invalid json value.

Still 750 channels not connected. Seem to be end X Beckhoff channels. Can connect to at least one of them from zotws12 but not conlog-master.

CP4 pressure

CP4 pressure trend over 7 days. We will lose trending of PT-245 after the bake starts (later this week?). Will try to estimate water content from curve later.

Shift Transition - Day

TITLE: 02/20 Day Shift: 16:00-00:00 UTC (08:00-16:00 PST), all times posted in UTC
STATE of H1: Planned Engineering
OUTGOING OPERATOR: None
CURRENT ENVIRONMENT:
    Wind: 7mph Gusts, 5mph 5min avg
    Primary useism: 0.02 μm/s
    Secondary useism: 0.19 μm/s
QUICK SUMMARY:

ISI config is in Large EQ mode since Friday Feb 16th. I will leave it this way until Jim gets here. Work being done at both ends so BRS turned of seems like a good way to let it be fo now.

Actually the laser is off to facilitate work involving the 70W amplifier.

Calibration of electric field meter and some suggestion for further measurements

Jeff Kissel will make the log entry on the electric field meter. The calibration of the field meter is Volts/(Volts/meter) =2.1 x 10^-2 flat from 10Hz to 20KHz.

The confusing results that Betsy, Sheila, Jeff and I got this afternoon may be due to the vibration and acoustic sensitivity of the electric field meter. Suggest further measurements with the worst acoustic and vibration sources turned off. Also the meter has a
common mode sensitivity to the battery voltage. I never connected the battery box to the neutral (white terminal). It would be good to connect the battery box itself to the lead coming from the field meter that attaches at the white terminal with a clip lead. If there is not a significant change in the low frequency noise, suggest turning off the ISI and other instrumentation in the chamber. That is if you have the time to further investigate where the low frequency noise originates.

Arm tumbleweed status

Kissel checked and confirmed that the Y-arm is passable this morning. As well, we see Mark baling along the X-arm. He are just now heading past the mid station and headed to the end.  Thanks Mark!

Lots of people on site this morning.

OPO escape efficiency before/after M1 swap

We have measured the escape efficiency of our OPO by injecting 1064nm light into the input/output coupler to measure intracavity losses, we did this both before and after swapping the input coupler.  Our final result for escape efficiency is 98.63+/- 0.03%, which means that we have 85+/- 36ppm of losses in addition to the transmission of M1+M2 in the cavity. 

Set up

We set up a new optical path to couple 1064 into the OPO input/output coupler to make an escape efficiency measurement.  On the optical table, we set up a Thorlabs fiber collimator F220FC-1064 (f=11.17mm), which has a waist of 437um at 1.13meters behind the collimator.  The attached photo shows how we modified the squeezing output path and the green pump injection path to inject this.  We left the -75mm ROC lens that was already placed and adjusted for the green mode matching in place, and added the ROC +150 lens for the translation stage temporarily at the edge of the platform to mode match this beam into the OPO.  We had a different mode matching solution for the first set of measurements (taken before the M1 swap), but decided to try to improve the mode matching for the final measurements.

Measurements:

We scanned the cavity using the PZT on M2, and made a fit for the voltage applied to the PZT vs cavity length using the transmitted 00 peaks, in the same way we did for 40362 Both before and after swapping M1, we recorded data as the PZT scanned over 4 FSRs, so the results here are the mean and standard error of the 4 measurements.  We estimated our mode matching using the peak heights (peak 00/(peak00+peak20)).  The reflected power on resonance over off resonance is corrected to account for this mode mismatch assuming that there is a signal on the PD from order modes equal to V_{off resonance}*(1-mode matching) that contributes to the measured voltage both on and off resonance. This gives us an estimate of the round trip losses other than input coupler transmission, including the transmission of M2 who's reflectivity was measured to be 0.99818636 in E1800011.  (Fabrice tells us that the mirrors installed in the H1 OPO before the M1 swap were  serial numbers 37, 11, 6 , 8 for M1 to M4 respectively in E1800011).

The escape efficiency is given by ln(R_{m1})/ln(R_m1*R_loss) where Rloss includes all losses and transmissions other than R1.  R_{m1}=0.87298077 before the swap, after.  For reference I've also included the maximum possible escape efficiency before and after the swap, is the m2 transmission was the only contribution to Rloss. 

	mode matching	reflected power dip on resonance	estimated dip with mode mismatch corrected	round trip loss (other than M1 transmission)	intracavity loss (excluding M2+M1 transmissions)	escape efficiency	escape efficiency with no intracavity loss
Before swap of M1	90.4+/-0.1%	94.8+/-0.1%	94.2+/-0.1%	2010+/-45 ppm	201+/-45 ppm	98.54+/-0.03%	98.68%
After swap of M1	96.3+/-0.1%	94.8+/-0.1%	94.6+/-0.1%	1900+/-36 ppm	85+/-36 ppm	98.63+/-0.03%	98.68%

More on mode matching correction

We tried to check that the correction for higher order modes reliable by taking one set of data where we intentionally misaligned the input beam, and attempted to correct for both the mode mismatch and misalignment higher order modes.  This gave us an inconsistent answer, which is why we were motivated to improve out mode matching for the final measurement.  I don't understand what is wrong with the higher order mode correction, that requires some more thought.

In the end, our losses are dominated by the transmission of M2, so this measurement gives us rather large uncertainty on the other losses in the cavity.  We can be confident that the escape efficiency is close to the best possible for the selected transmissions. 

After finishing this Friday we restored the green injection path, and worked on some of the remaining items on the VIP platform.  There is some remaining work to be done on the VIP before balancing it.  

CP4 area looking good

Kyle and I finished removing the GV12 annulus tubing (except for gate annulus, which is double-valved out under vacuum), installing blanks, cleaning up loose ends and preparing the area for Tuesday morning. Both of us are leaving the site now.

DBB Measurements Prior to 70W Amplifier Install

This afternoon I tweaked up the DBB and took a round of measurements prior to the 70W amplifier install.  Something appears to be not quite right with this NPRO laser.  Both the frequency and pointing noise measurements show a very large peak between 100 Hz and 500 Hz, with the peak being somewhere in the neighborhood of 260ish Hz.  This looks similar to the peak from Peter's NPRO measurements from this morning.  We'll have to look into this first thing on Tuesday morning.  Perhaps our decision to keep the old NPRO power supply installed was not a wise one, as there can sometimes be odd behavior when using a NPRO with a different power supply.  Swapping in the new power supply is fairly painless, so this will be easy to check, although we will then lose the ability to remote start the NPRO laser, and therefore the PSL as well.

I dug up the acceptance test results for this laser (T1500521) and the same peak is present when the
power supply that came with the laser was used.  So it is not likely to be solely due to the different
power supply.

VIP aligned for 1064 and 532 before M1 swap

Sheila, Nutsinee, Terry,

This is an update on the progress so far on the VIP. We have aligned and mode matched both the CLF/seed 1064 path and the 532 pump path to the OPO, and are ready to think about swapping M1 for the higher green reflectivity version.  

• We have collimators which were labeled SN18 for 1064 and SN4 for 532.  Maggie measured the modes out of these collimators and posted her data here.  Terry and I also measured both wavelengths in both collimators, here, but at that time the 1064 and 532 collimators were somehow swapped (so the collimator called "supposedly for 1064" in that log is now being used for 532 nm and vice versa.).  Nutsinee also made a better measurement of the mode out of the collimator now being used for 532 in the far field here.
• The first attached photo shows the path from the 1064 collimator to M2 where it is injected into the OPO.  The distance from the collimator to the steering mirror is 173mm, the total distance from the collimator to the AR side of M2 is 270 (+/-~1) mm, from the collimator to the edge of the OPO mounting block is 226mm, and the distance from the collimator to the ROC+150mm lens (f=334mm according to this) is 41mm.  After the lens is a thin film polarizer type 2 which transmits P polarized light, followed by a half wave plate to rotate the polarization back to vertical as required for the OPO.  
• The second attachment shows the 532 pump path.  The distance from the collimator to the first steering mirror is 180mm, the total distance from the collimator to the edge of the metal block the cavity sits on is 190mm, the total distance to the AR surface of M1 is ~234mm.  The first lens is ROC+75mm (f=162.8mm) 152mm from the collimator, while the second lens is 199 mm from the collimator (19 mm from the steering mirror).  This path has a thin film polarizer and half wave plate similar to the 1064 path.  
• We scanned the cavity using the M2 PZT and a thorlabs PZT driver.  Using the free spectral range of the OPO 853.452MHz from T1700104, I did a quadratic fit of the measured 00 peaks of 1064 transmission through M1 to rescale the voltage applied to the PZT driver into resonant frequency of the OPO.  The higher order mode peak is the mode mismatch. From these four measurements the mode matching is 81.1+/- 0.2% standard error.  We did not try to optimized the mode matching of this path, but we can come back and attempt to adjust it if there is time before installation.  
• The dips in reflected power are 95.7+/-0.1% of the power off resonance, without correcting for the higher order modes.  While this is consistent with our expectation for a 99.8% reflectivity M2 and 87.2% reflectivity M1, this give us a measurement of the cavity losses which is dominated by the transmission through M1, and doesn't give us a good measurement of the OPO escape efficiency. 
• Although the documentation calls for two dichorics in the squeezing path, we had only one superpolished dichroic so we used it to separate the green and red and use 1064 HR mirrors for the rest of the squeeze path. 
• Nutsinee has and will post data from the 532nm cavity scans. 

ISCT6 Detector calibration

Daniel, Sheila, Nutsinee

Nominal laser output power measured (with a PDA100A) as 18 mW through a 98% beam splitter (Rp 98%). Transimpedance=1500 Ohms, responsivity=.221A/W (variable gain setting on PDA100A set to 0dB).

Green output power measured (with a PDA100A) as 2 mW through 95% beam splitter (~100mW IR -> 40mW green). Transimpedance=1500 Ohms, responsivity=.313A/W (variable gain setting on PDA100A set to 0dB).

NewFocus 1611 detector to lock laser to PSL: Beat frequency signal measured with spectrum analyser ~ -14dBm at 155MHz as measured from the -1dB coupled output on the TTFSS pre-amp. Note there is a signal decrease by around 5dB with large (squeezing) laser frequency shifts (~500MHz or more) that seems to be due to beam pointing errors on the 1611 detector. However locking signal depends on phase and is largely insensitive to amplitude fluctuations so we should be ok. Responsivity=.75A/W, Transimpedance=-10k Ohm, gain setting 0, Voltage = -1.6V.

Power to 1611 detector: .30mW from PSL + .67mW from sqz laser -> .49mW on detector after 50/50 beam-splitter. MEDM screen reads .21mW ?? If the transimpedance is adjusted to -5k Ohm MEDM screen reads correct, but I suspect something is still odd about this. 

Fibre (PSL) power rejected = 1.3 uW measured with a PD1A detector (2 K impedance).

Fibre (PSL) power launched = 27 uW measured with a PD1A detector from a 10% beam splitter. Disabled gain selection setting (alog 40161) has been corrected. Note the beamsplitter was changed from 2% transmission in the original drawing (BS8) to 10% transmission.