Fri Jul 22 17:41:01 2022, Koji, General, General, SRS LCR meter SRS720 returned to Downs
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SRS LCR meter SRS720 was returned to Downs as before.
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Mon Jul 1 12:49:42 2019, Koji, Optics, Characterization, Scattering measurement of A and C mirrors 
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Liyuan's scattering measurement for the A and C mirrors. |
Mon Nov 7 21:16:16 2022, Camille, Optics, Configuration, Setting up the fiber couplers  
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[Camille, Koji]
Began setting up fiber assembly for OMC testing:
-Aligned fiber mount to maximize transmission through fiber |
Mon Nov 7 22:00:33 2022, Koji, Optics, Configuration, Setting up the fiber couplers
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Fiber matching: 43.2/56.7 = 76%
S/P-pol ratio 0.7/43.2 = 1.6%
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Mon Apr 22 09:54:21 2019, Joe, General, , Shortening cavity (A5,A14,PZT11,PZT22) to get closer to design FSR 
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[Koji,Joe,Philip,stephen]
in units 20um per div on the micrometer [n.b. we reailised that its 10um per div on the micrometer]
CM1 inner screw pos: 11.5 |
Thu Nov 8 19:47:55 2012, Koji, Electronics, Configuration, Solder for PZTs
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Rich saids:
I have ordered a small roll of solder for the OMC piezos.
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Mon Dec 31 03:10:09 2012, Koji, Optics, General, SolidWorks model of the OMC breadboard 
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Sun Jan 6 23:22:21 2013, Koji, Mechanics, General, SolidWorks model of the OMC suspension 
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Sat Jul 1 21:33:18 2017, Koji, General, General, Some purchase notes
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- Forgot to close the cylinder valve...
v HEPA prefilter (20"x20"x1" MERV 7)
- Replace the filter for the air conditioning |
Wed Jun 5 18:19:51 2013, Koji, General, General, Some recent photos from the OMC final test at CIT
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Applying First Contact for the optics cleaning
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Mon Jul 21 01:02:43 2014, Koji, Mechanics, Characterization, Some structual mode analysis 6x
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Prisms
Fundamental: 12.3kHz Secondary: 16.9kHz
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Mon May 6 19:31:51 2013, Koji, Optics, Characterization, Spot position measurement on the diode mounts   
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Measurement Order: DCPD2->DCPD1->QPD1->QPD2
DCPD1: 1.50mm+0.085mm => Beam 0.027mm too low
DCPD2: 1.75mm+0.085mm => Beam 0.051mm too high (...less confident) |
Wed May 8 15:08:57 2013, Koji, Optics, Characterization, Spot position measurement on the diode mounts   
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Remeasured the spot positions:
DCPD1: 1.50mm+0.085mm => Beam 0.084mm too high
DCPD2: 1.50mm+0.085mm => Beam 0.023mm too high |
Tue Aug 27 17:02:31 2013, Koji, Mechanics, Characterization, Spot position measurement on the diode mounts
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After the PZT test, the curved mirrors were aligned to the cavity again.
In order to check the height of the cavity beam, the test DCPD mount was assembled with 2mm shim (D1201467-3)
The spot position was checked with a CCD camera. |
Mon Mar 3 02:46:21 2014, Koji, General, Characterization, Spot positions scanned
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Spot positions on CM1 and CM2 scanned according to the recipes provided by the previous entry.
The best result obtained was:
Transmission from FM2: 32.7mW |
Fri Sep 13 15:09:20 2013, Koji, General, General, Sprinkler installation: done 
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A sprinkler head was installed on the HEPA enclosure. The head is covered with a plastic cap. |
Tue Sep 9 20:59:19 2014, Koji, Mechanics, Characterization, Structural mode analysis for the PZT mirror 6x
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Structural analysis of the PZT mirror with COMSOL.
Inline figures: Eigenmodes which involves large motion of the tombstone. In deed 10kHz mode is not the resonance of the PZT-mirror joint,
but the resonance of the tombstone. |
Sat Feb 2 16:17:13 2019, Koji, Optics, Characterization, Summary: OMC(001) HOM structure recalculation   
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Each peak of the transfer function measurement was fitted again with a complex function:
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Sat Feb 2 20:03:19 2019, Koji, Optics, Characterization, Summary: OMC(002) HOM structure recalculation (before mirror replacement)   
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OMC (002)
History: Measurement date 2013/10/11, Installed to L1 2013/XX |
Sat Feb 2 20:28:21 2019, Koji, Optics, Characterization, Summary: OMC(003) HOM structure recalculation   
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OMC (003)
History: Measurement date 2014/7/5, Stored for I1, Installed to H1 2016/8 upon damage on 002 |
Fri Jun 27 18:51:33 2014, Koji, General, General, Supply
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PTOUCH TAPE (12mm white) x 2
9V batteries |
Fri Nov 11 19:07:48 2022, Koji, Supply, General, Supply Order
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Clean Supply Ordered
TexWipe TX8410 AlphaSat Vectra Alpha 10 50 sheets x 12 pk (VWR TWTX8410)
Mask KIMTECH PURE®
M3 Pleat-Style Face Masks 50 masks x 10 pk (VWR 15628-213)
Stainless Pan x3 (VWR 10193-562)
Ansell Accutech Latex Gloves 6.5 |
Fri Oct 9 01:01:01 2020, Koji, General, General, TFT Monitor mounting    
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To spare some room on the optical table, I wanted to mount the two TFT monitor units on the HEPA enclosure frame.
I found some Bosch Rexroth parts (# 3842539840) in the lab, so the bracket was taken for the mount. This swivel head works very well. It's rigid
and still the angle is adjustable. |
Fri Oct 16 00:53:29 2020, Koji, General, General, TFT Monitor mounting
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The image flipping of the display unit was fixed. The vendor told me how to fix it.
- Open the chassis by the four screws at the side.
- Look at the pass-through PCB board between the mother and display boards. |
Mon Dec 19 18:51:50 2022, Koji, Optics, Characterization, TMS measurement with the PZT voltages altered    
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[Camille, Koji] Log of the work on Dec 15, 2023
The vertical and horizontal TMSs for OMC #4 were measured with the PZT voltages scanned from 0V to 200V.
We concluded that this alignment nicely avoids the higher-order mode structure up to ~19th order. We |
Mon Jul 23 17:15:14 2012, Koji, Clean, General, Talking with Margot
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I consulted with Margot about the cleaning of the optics
Optics are considered as a clean object. Large dusts can be removed by ionized N2 flow etc.
Barrel of optics can be wiped
with Acetone.
Optical surfaces are best to be cleaned by First Contact.
A peek |
Thu Mar 28 03:37:07 2013, Zach, Optics, Configuration, Test setup input optics progress  
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[Lisa, Zach]
Last night (Tuesday), I finished setting up and aligning most of the input optics for the OMC characterization setup. See the diagram below, but
the setup consists of: |
Sun Jul 20 17:20:39 2014, Koji, General, General, The 3rd (LIO) OMC was shipped out to LHO
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The 3rd (LIO) OMC was shipped out to LHO on Friday (Jul 18) Morning.
At LHO
- All of the on-breadboard cables should be attached and tied down. |
Wed Jul 5 16:59:44 2017, Koji, General, General, The OMC #002 was packed
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[Stephen Koji]
The OMC #002 was packed for the transportation to Downs.
===> And transported to Downs 227 on Jul 6th. |
Mon Nov 23 23:17:19 2020, Koji, Electronics, Characterization, The dark noise of the Q3000 QPDs   
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The dark noise levels of the four Q3000 QPDs were measured with FEMTO DLPCA200 low noise transimpedance amp.
The measurement has been done in the audio frequency band. The amp gain was 10^7 V/A. The reverse bias was set to be 5V and the DC output of
the amplifier was ~40mV which corresponds to the dark current of 4nA. It is consistent with the dark current measurement. |
Tue Nov 24 10:45:07 2020, gautam, Electronics, Characterization, The dark noise of the Q3000 QPDs
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I see that these measurements are done out to 100 kHz - I guess there is no reason to suspect anything at 55 MHz which is where this QPD will be reading
out photocurrent given the low frequency behavior looks fine? The broad feature at ~80 kHz is the usual SR785 feature I guess, IIRC it's got to do
with the display scanning rate. |
Tue Nov 24 12:27:18 2020, Koji, Electronics, Characterization, The dark noise of the Q3000 QPDs
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The amplifier BW was 400kHz at the gain of 1e7 V/A. And the max BW is 500kHz even at a lower gain. I have to setup something special to see the RF band
dark noise.
With this situation, I stated "the RF dark noise should be characterized by the actual WFS head circuit." in the 40m ELOG. |
Wed Jan 25 23:51:04 2023, Koji, General, General, The items packed for Downs
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Qty1 1/2 mounts
Qty2 prism mounts
Qty6 gluing fixures |
Thu Jul 21 17:47:00 2022, Koji, General, General, The profile of the beam incident on the fiber input coupler
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The profile of the beam incident on the fiber input
The fiber input was deflected by a 45deg mirror. The beam profile was measured with WincamD. The beam was too strong (~60mW) even at the smallest
pump power (ADJ -50) of the NPRO. So the two ND20 filters were added to the lens right before the 45 deg mirror and the camera. |
Tue Jun 28 16:13:34 2022, Koji, General, General, The small optical table not small enough to get out
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The table width was an inch too large compared to the door width. We need to tilt the table and it seemed too much for us. Let's ask the transportation
for handling.
Photo courtesy by Juan |
Wed Jan 2 07:35:55 2013, Koji, Optics, Characterization, Thickness of a curved mirror
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Measured the thickness of a curved mirror:
Took three points separated by 120 degree.
S/N: C2, (0.2478, 0.2477, 0.2477) in inch => (6.294, 6.292, 6.292) in mm |
Tue Dec 10 16:41:51 2013, Koji, General, General, To Buy
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Masks / Wipes => done |
Mon Jul 7 01:36:03 2014, Koji, General, General, To Do
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Optical tests
Cleaning
Power Budget
FSR measurement
TMS
measurement
TMS measurement (with DC voltage on PZTs)
PZT DC response
PZT AC response
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Thu Jul 10 08:34:57 2014, Koji, General, General, To Do
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Optical tests
Cleaning
Power Budget
FSR measurement
TMS
measurement
TMS measurement (with DC voltage on PZTs)
PZT DC response
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Sat Jun 16 08:53:09 2012, Koji, General, General, To Do List
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Facility
Work
Replacing wooden work benches
W60" x H28-34" x D30" |
Fri Aug 26 22:29:02 2022, Koji, General, General, Tool Shipping Prep  
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Shipping preparation for the LLO trip
Started July 15, 2022 and finished Aug 30. So it took ~1.5 months (with a
couple weeks of break)
Class B special tools |
Wed Jun 20 20:37:45 2012, Zach, Optics, Configuration, Topology / parameter selection 8x
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EDIT (ZK): All the plots here were generated using my MATLAB
cavity modeling tool, ArbCav |
Fri May 26 21:53:20 2017, Koji, General, Configuration, Trans RF PD setup
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Recent work
- DC output of the trans RF PD was connected to the BNC patch panel. => Now CH4 of the scope is monitoring this signal
- The RF sweep signal from the network analyzer is connected to the power combiner for the EOM drive via the SMA patch panel. |
Tue Jun 6 00:49:48 2017, Koji, General, Configuration, Trans RF PD setup
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Last week, I further worked on the RF system to install 20dB coupler on the agilent unit and setup the R channel. This allowed me to make the FSR/TMS
measurement of the OMC.
And today several optical improvement has been done. |
Tue Jun 6 22:00:36 2017, Koji, General, Configuration, Trans RF PD setup
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- Replaced the PZT with the one used from the beginning. This must be PZT #21. After the replacement, the spot positions look very good. I even went
up. So I decided this is the configuration to proceed to the gluing. The CM1 mirror has the HR arrow at the top.
- The input beam was realigned w.r.t. the OMC. |
Mon Nov 21 19:13:35 2022, Koji, General, General, Transmission measurement (2nd deep cleaning of OMC #1) 
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OMC Transmission measurement after the 2nd deep cleaning
The 2nd deep cleaning didn't improve the transmission. (See Attachment 2)
The measured loss was 0.044+/-0.002 |
Fri May 31 14:07:54 2013, Koji, Optics, Characterization, Transverse Mode Spacing measurement afte the baking 
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Measurement for pitch
Free Spectral Range (FSR): 264.9703 +/− 0.0007 MHz
Cavity roundtrip length: 1.131419 +/− 0.000003 m |
Mon Aug 22 12:58:16 2016, Koji, General, General, UV bond samples -> Garilynn
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- FS base + Mounting Prism
- FS or SF2 1/2" piece + FS or SF2 1/2" piece
- FS? plate + FS or SF2 1/2" piece + FS or SF2 1/2" piece + FS? plate |
Thu Feb 7 23:01:45 2013, Koji, Optics, Characterization, UV epoxy gluing test
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[Jeff, Yuta, Koji]
Gluing test with UV-cure epoxy Optocast 3553-LV-UTF-HM
- This glue was bought in the end of October (~3.5 months ago). |
Mon Apr 1 03:23:48 2013, Koji, Optics, General, UV power calibration
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[Koji Lisa Jeff Zach]
Eric G bought a UV power meter from American Ultraviolet.
Our UV illuminator was calibrated by this power meter. |