 Sat May 17 07:40:14 2014, Koji, Optics, Characterization, I1OMC cavity mirrors glued 
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I1OMC cavity mirrors were glued.
FSR = 264.82MHz => Lcav = 1.132m (nominal 1.132m)
TMS/FSR for Vpzt1=Vpzt2=0: 0.2185 (V) and 0.2196 (H) (nominal 0.219) |
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Fri May 16 00:13:36 2014, Koji, Optics, Characterization, Cavity mirror gluing part 1
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BS1/FM1/FM2 for I1OMC were glued.
FM1 had to be intentionally rotated.
FM1 had to be intentionally shifted to avoid scattering spot. |
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Wed May 14 02:15:15 2014, Koji, Optics, Characterization, FSR/TSM adjustment of the OMC cavity
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1. FSR was adjusted and measured with "the golden arches" technique again.
FSR = 264.8412 MHz +/- 1400Hz => Lcav = 1.13197 m. (nominal 1.132m)
2. Transverse mode spacings for the vertical and horizontal modes were measured. |
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Mon May 12 22:43:02 2014, Koji, Optics, Characterization, Measured FSR/TSM of the OMC cavity
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Data analysis of the FSR/TSM measruement last week.
1. FSR was measured with "the golden arches" technique.
FSR = 263.0686 MHz +/- 900Hz |
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Thu Apr 17 21:39:25 2014, Koji, Optics, General, More alignment
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STORY:
- The cavity mirrors have scattering spots. The cavity alignment should have been scanned to find a cavity mode to have lowest loss possible.
BTW, We only have horizontal dof for the alignment scan. |
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Tue Mar 25 17:10:10 2014, Koji, Optics, Characterization, OMC spot position estimation
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| Spot positions were inferred from the photos |
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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 |
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Fri Feb 28 19:50:11 2014, Koji, General, General, Misalignment ABCD matrix for the aLIGO OMC
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Relationship between mirror misalignment and cavity mode shift was calculated.
The technique described in T0900647 by Sam Waldman was used.
The angles and displacement of the mirrors and beams are defined in the attached figure. |
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Tue Feb 18 18:58:38 2014, Koji, General, General, LHO H1 OMC installation photos
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LHO OMC installation photos
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Tue Dec 10 16:41:51 2013, Koji, General, General, To Buy
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| Masks / Wipes => done |
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Thu Nov 21 00:05:35 2013, Koji, General, General, H1OMC electronics arrangement
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Checked the PZT arrangement: Mighty Mouse Pin1&2 -> PZT2 (DCPD side), Mighty Mouse Pin3&4 -> PZT1 (QPD side)
DCPD response:
Illuminate DCPD1 (T) -> DCPD B responded in MEDM |
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Mon Nov 4 19:43:56 2013, Koji, General, General, H1OMC Packed
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H1OMC PZT connector was replaced with the correct one. This was the final step for H1OMC.
Jeff and I packed the OMC and put it in the perikan case. It will be shipped tomorrow.
The other tools are also packed in the other box. Here is the list of the items |
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Wed Oct 23 02:45:07 2013, Koji, General, General, PD realignment
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DCPD2 got misaligned during the cable installation. The PD alignment procedure have been gone through again.
Cavity locking
- Removed the FC layers for the cavity related mirrors. |
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Tue Oct 22 17:17:59 2013, Koji, General, General, H1OMC cabling
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[Chub, Jeff, Koji]
We worked on the wiring and routing of the cables.
- The cables for the PZT was installed first. |
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Tue Oct 15 18:50:08 2013, Koji, Optics, Characterization, QPD alignment
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1) Deburr the bottom surfaces of the QPD housings
2) Aligned the QPDs
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 Wed Oct 16 19:16:29 2013, Koji, Optics, Characterization, PD alignment
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shim 1.5mm 001/002 |
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Mon Oct 14 15:50:55 2013, Koji, Optics, Characterization, H1 OMC Power budget
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LHO OMC power budget
Date
2013/9/17
2013/9/17
2013/10/16
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Mon Oct 14 13:40:16 2013, Koji, Optics, Characterization, H1 OMC Optical testing
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Since the middle of September, the optical tests of H1 OMC were took place.
Here is summary of the progress.
TEST1: FSR/FINESSE measurement before applying First Contact |
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Sat Sep 7 17:20:56 2013, Koji, General, General, OMC/PD lab optical table wrapping
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[Koji Jeff]
In order to prepare for the splinkler installation on the HEPA enclosure, the table with the optics was wrapped with Ameristat sheets. |
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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. |
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Wed Sep 4 22:22:54 2013, Koji, General, General, H1 OMC wrapped and moved to the bake lab.
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[Koji, Jeff]
We moved the H1OMC to the bake lab.
Chub set up the vacuum bake oven (Oven F) and running without the actual OMC. |
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Tue Sep 3 17:03:25 2013, Koji, General, General, H1 OMC gluing completed
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[Koji Jeff]
H1 OMC All Gluing completed
5 Glue H1 beam dumps (UV) |
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Fri Aug 30 12:25:29 2013, Koji, General, General, H1 OMC Invar mount gluing
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The Invar Mounting Blocks were glued on the breadboard.
Serial number #1/2/5/6/7/8 -> I1 OMC cable side
Serial number #9/10/11/12 -> H1 OMC cavity side |
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Fri Aug 30 12:24:28 2013, Koji, Optics, Characterization, H1OMC Spot positions
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Beam heights on the diodes
DCPD1: 14.459mm -> With 1.5mm shim, the beam will be 0.038mm too low. |
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Fri Aug 30 12:22:56 2013, Koji, Optics, General, H1 OMC Cavity side UV gluing
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H1 OMC Cavity side optics was glued on the breadboard
Curved mirror gluing
- Applied the UV glues to CM1/CM2 prisms. |
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Fri Aug 30 12:14:50 2013, Koji, Optics, General, H1 OMC Cavity length adjustment
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Short conclusion:
The roundtrip cavity length for the H1 OMC was adjusted to be 1.145m
instead of 1.132m such that the 19th HOMs of the lower sideband do not get resonant together with the carrier. |
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Thu Aug 29 18:55:36 2013, Koji, Mechanics, General, I1 OMC top side gluing (UV)
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The glass components for the I1 OMC top side were glued by the UV glue.
Breadboard SN#4
Wire bracket SN#5/6/7/8 |
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Thu Aug 29 02:52:50 2013, Koji, Optics, Characterization, H1OMC Curved Mirror Alignment
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Cavity parameter was measured with 50V bias on PZT1 (CM1)
- PZT combination was changed: PZT1 #21 (PZT ASSY#6) / PZT2 #25 (PZT ASSY #4)
- 19th HOMs of the USB makes accidental resonance with the nominal cavity length. |
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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. |
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Thu Aug 22 15:40:15 2013, Koji, Electronics, Configuration, PZT endurance test
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[Koji, Jeff]
Background
In response to the failure of one of the PZTs on L1OMC (LLO:8366), we |
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Fri Aug 23 19:24:32 2013, Koji, Electronics, Configuration, PZT endurance test (II)
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The PZT tests were finished with the conclusion that the PZT won't be damaged with our expected usage.
This is another test of the PZTs to make sure small (~10V) reverse voltage does not break the PZTs.
Background |
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Thu Aug 22 15:34:03 2013, Koji, Optics, General, OMC Cavity side gluing
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[Koji Jeff]
o BS1, FM1, FM2 prisms were glued
=> This fixed the unstability of the OMC locking |
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Wed Aug 21 08:31:21 2013, Koji, Optics, Characterization, H1 OMC cavity alignment
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Alignment of the H1 OMC cavity mirrors
- The cavity mirrors as well as the first steering mirror were aligned on the cavity side template.
- The locking of the cavity was not so stable as before. Some high freq (several hundreds Hz) disturbance makes the cavity |
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Fri Aug 16 17:21:38 2013, Koji, General, General, [OMC002] Build started
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[Jeff Koji]
The breadboard (SN2) was loaded on the transportation fixture.
The laser side template was installed and the cavity mirrors were placed. |
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Fri Aug 16 16:36:19 2013, Koji, Optics, General, Optics List
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Link to the "Mirror/PZT Characterization links"
Breadboard
BB1 OMC(001) OMC |
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Tue Apr 16 09:43:58 2013, Koji, Optics, Configuration, Mirror list for L1OMC
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L1 OMC
Cavity Mirrors
FM1 (input coupler): A8 |
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Fri Aug 16 15:31:17 2013, Koji, Optics, Configuration, Mirror list for OMC(002)
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OMC(002)
Cavity Mirrors
FM1 (input coupler): A9 |
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Fri Aug 9 10:09:56 2013, Koji, General, General, PZT Assembly #3/#4
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Yesterday, Jeff and I bonded the PZT assemblies (#3/#4).
The attached is the arrangement of the components |
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Mon Aug 12 20:22:19 2013, Koji, General, General, PZT Assembly #5/#6
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PZT Assembly #5/#6 were glued on Fri Aug 9th
They are removed from the fixture on Mon Aug 12th.
All of the four PZT assemblies were moved to the OMC lab. |
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Sat Jul 6 17:10:07 2013, Koji, Mechanics, Characterization, PZT Response analysis
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Analysis of the PZT scan / TF data taken on May 31st and Jun 1st.
[DC scan]
Each PZT was shaken with 10Vpp 1Hz triangular voltage to the thorlabs amp. |
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Fri Jun 28 12:20:49 2013, Koji, General, General, Dmass's loan of Thorlabs HV amp
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http://nodus.ligo.caltech.edu:8080/Cryo_Lab/799
(KA: Returned upon H1OMC building) |
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Tue Jun 18 15:45:38 2013, Koji, General, General, [LLO] OMC installation in HAM6
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OMC installed in HAM6!
https://alog.ligo-la.caltech.edu/aLOG/index.php?callRep=7486
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Tue Jun 18 10:01:11 2013, Koji, Optics, Characterization, Cavity Finesse analysis
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This is the analysis of the cavity finesse data taken on Apr/13/2013 (before baking), May/30/2013 (after baking), and Jun/02/2013 (after cleaning).
If we believe this result, baking contaminated the cavity, and the first contact removed it. That agrees with the power measurement of the transmitted
light. |
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Fri Jun 14 06:35:21 2013, Jeff, General, General, [LLO] L1 OMC status
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https://alog.ligo-la.caltech.edu/aLOG/index.php?callRep=7410
Weights:
Suspension cage and transportation box: 250.8lb |
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Thu Jun 13 12:12:20 2013, Zach, General, General, [LLO] OMC and OMCS in LVEA
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https://alog.ligo-la.caltech.edu/aLOG/index.php?callRep=7395
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Thu Jun 13 12:04:57 2013, Koji, General, General, [LLO] OMC Optical Test - completed
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| https://alog.ligo-la.caltech.edu/aLOG/index.php?callRep=7373 |
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Mon Jun 10 10:04:37 2013, Koji, General, General, [LLO] OMC Test
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[Koji Zach]
We worked on the OMC test over the weekend.
- At the beginning, the measured OMC transmission was ~85% even after subtracting the junk light and sidebands from the calculation. |
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Fri Jun 7 16:04:44 2013, Koji, General, General, [LLO] OMC arrived
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[Koji Zach Suresh]
The OMC arrived at LLO without any destruction!
We found that one shock sensor on the box turned red, the other stayed white.
We brought the Perican case to the changing |
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Wed Jun 5 18:51:31 2013, Koji, General, General, L1 OMC shipped out
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[Koji, Jeff]
The L1 OMC finally sent out from Caltech!
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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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Wed Jun 5 01:06:35 2013, Zach, General, Characterization, L1 OMC as-built diagram
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D1300507
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Mon Jun 3 21:19:03 2013, Koji, General, General, Planning
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Monday - Evening
(Koji)
[done] - DCPD alignment |
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Mon Jun 3 18:58:08 2013, Koji, Optics, Configuration, OMC final tests
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- QPD mount aligned, QPD output checked
The spots are with 100um from the center of the diodes. [ELOG Entry (2nd photo)]
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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 |
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Thu May 30 15:00:28 2013, Koji, Optics, General, QPD alignment
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The QPD alignment was adjusted using the aligned beam to the cavity and the 4ch transimpedance amplifier.
As I have a test cable for the QPD, I attached a DB9 connector on it so that I can use the QPD transimpedance
amplifier to read the photocurrent. The transimpedance of the circuit is 1kV/A. |
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Fri May 31 05:46:54 2013, Koji, Optics, General, QPD alignment
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Peter F suggested to check the bottom surface of the PD housings if there is any protrusion/interference/whatever.
And that was true! It was found that the front side of QPD1 (Left) was lifted by a machining burr.
It seems that this burr consistently exists as the other one also have it (see QPD2 picture (right)) although it is not too terrible compared to |