 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 |
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 |
 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 |
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Thu May 30 14:38:42 2013, Koji, Electronics, General, Cable fitting
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Yesterday Jeff and Chub worked on the cabling of the OMC. It turned out that the gender of the cable connectors
going from the cavity side to the connector bracket on top of the OMC were opposite from what is needed.
This way, the connectors can't fixed on the cable harness, thus they are free during the shipping. |
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Thu May 23 23:41:48 2013, Koji, Mechanics, General, DCPD/QPD Mount
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DCPD mounts and QPD mounts were attached on the breadboard. They are not aligned yet and loosely fastened.
DCPD (mounting 4-40x5/16 BHCS Qty4)
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Wed May 8 15:36:50 2013, Koji, General, General, Latest OMC schedule
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May
(done) Mon 6th: Invar plate arrival / Spot position measurement
(done) Tue 7th: Invar plate cleaning / Spot position measurement
/ EP30-2 arrival / Invar plate gluing to the test mounting brackets
(done) Wed 8th: Invar plate cleaning done / Baking of the test pieces (with Bob's
oven)
Thu 9th: ***After bake torque/force test***
***If the invar plate passes the test***
Thu 9th Light side invar plate gluing
Fri 10th Cable |
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Mon May 13 15:00:23 2013, Koji, General, General, Current most reliable OMC schedule
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May
Tue 14th The OMC given to Bob (Air bake & Vac bake)
Mon 20th The OMC received from Bob
Apply First contact
Diode mount adjustment / Electronic tests
Tue 21st Diode mount adjustment / Electronic tests / Optical tests
Wed 22nd Final cabling (***Chub***)
Thu
23rd Final cabling / Packing
Fri 24th Packing / Shipping
Mon 27th? Arrival to LLO / Koji fly to LLO
Tue 28th Test on the optical bench
Wed 29th Test |
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Tue May 21 18:28:08 2013, Koji, General, General, Current most reliable OMC schedule
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- The wrong Mighty Mouse connectors for the PZT wires were prepared. The correct ones are in the vacuum oven till Tuesday morning.
- The thread holes for the cable pegs are 1/4-20 rather than 10-24. This requires re-machining of the cable pegs & the C&B.
- We are waiting for the fast shipment of the from LHO |
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Mon May 20 14:59:21 2013, Koji, General, General, OMC is out from the oven
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The OMC came back to the table again.
No obvious change is visible: no crack, no delamination
The OMC was fixed on the table and the beam was aligned to the cavity |
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Tue May 14 19:06:00 2013, Koji, Clean, General, OMC Baking
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The OMC is in the air bake oven now.
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Mon May 13 14:59:16 2013, Koji, Mechanics, General, Invar shim gluing
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The invar reinforcement shims were glued on the glass brackets on the breadboard.
We worked on the light side on May 10th and did on the dark side on May 13rd.
U-shaped holding pieces are used to prevent each invar shim to be slipped from the right place. |
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Mon May 13 14:49:35 2013, Koji, Mechanics, Characterization, Mounting Glass Bracket still broke with tightenin stress
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[Koji / Jeff]
This is the elog about the work on May 9th.
We made two glass brackets glue on the junk 2" mirrors with the UV glue a while ago when we used the UV bonding last time. |
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Fri May 10 09:33:22 2013, Koji, Supply, General, COMSOL simulation on the glass bracket stress
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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) |
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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 |
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Fri May 3 21:09:08 2013, Koji, General, General, OMC is back
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| L1 OMC is back on the table for the action next week. |
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Thu Apr 18 11:59:02 2013, Koji, General, General, DCPD path gluing
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[Jeff, Koji]
DCPD path gluing
Usual preparation |
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Thu Apr 18 11:43:59 2013, Koji, General, General, Mounting Glass Bracket Failure
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[Jeff, Koji]
- While we were working on the optics alignment, one of the mounting brackets made of glass god tore apart into two when a holding screw was removed.
The glass component had a crack at the very middle of the part. |
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Wed Apr 17 07:30:04 2013, Koji, Optics, General, QPD path glued
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Yesterday, all of the glass components for the QPD path were glued.
- Check the alignment of the beam with the cavity. |
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Thu Apr 4 01:43:06 2013, Koji, Optics, Characterization, Mirror T measurement
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[Zach, Koji]
The measurement setup for the transmission measurement has been made at the output of the fiber.
- First, we looked at the fiber output with a PBS. It wasn't P-pol so we rotated the ourput coupler. |
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Mon Apr 8 11:11:37 2013, Koji, Optics, Characterization, More Mirror T measurement
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More Ts of the mirrors were measured.
A mirror specification:
Request: 8300+/-800 ppm |
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Tue Apr 16 08:12:14 2013, Koji, Optics, Characterization, Further More Mirror T measurement
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T&Rs of the B mirrors and some of the E mirrors are measured.
I found that these BSs have high loss (1%~3%) . As this loss will impact the performance of
the squeezer |
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Tue Apr 16 23:26:51 2013, Koji, Optics, Characterization, Further More Mirror T measurement
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Since the previous measurement showed too high loss, the optical setup was checked.
It seemed that a PBS right before the T&R measurement setup was creating a lot of scattering (halo) visible with a sensor card.
This PBS was placed to confirm the output polarization from the fiber, so it was ok to remove it. |
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Tue Apr 16 00:40:45 2013, Koji, Optics, General, PD/QPD path gluing ~ preparation
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[Jeff Koji]
- Placed the optics on the PD/QPD path
- Checked the alignment of the beam on the dummy PD/QPD mounts |
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Sat Apr 13 21:06:02 2013, Koji, Optics, General, OMC Bottom-side: cavity glued
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[Jeff, Zach, Lisa, Koji]
Gluing of the cavity mirrors went very well!!!
Preparation |
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Fri Apr 12 09:25:31 2013, Koji, Optics, Characterization, Alignment of the OMC (without glue)
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[Zach Koji]
The first attempt not to touch the curved mirrors did not work. (Not surprising)
The eigenmode is not found on the mirror surface. |
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Thu Apr 11 15:10:22 2013, Koji, General, General, OMC Progress
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[Zach, Jeff, Koji]
- Jeff configured the bottom side template to have a nominal value
obtained from the solid works model. Note that the thickness of the |
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Wed Apr 10 00:40:30 2013, Zach, Optics, Configuration, fauxMC locked
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[Koji, Zach]
Tonight, we locked the "fauxMC". We obtained
a visibility of >99%. |
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Mon Apr 8 21:11:14 2013, Koji, Optics, General, PZT assembly gluing
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[Jeff, Zach, Koji]
PZT assembly gluing
Glue gun -> to be returned to MIT |
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Tue Apr 9 13:56:09 2013, Koji, Optics, General, PZT assembly post gluing / pre baking pictures
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Mon Apr 8 23:42:33 2013, Koji, Optics, Configuration, Fake OMC roughly aligned
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Mode matching:
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Mon Apr 8 20:56:52 2013, Koji, Optics, Configuration, PZT & Curverd Mirror arrangement
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Assembly #1:
Mounting Prism #16
PZT #26 |
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Mon Apr 8 11:49:18 2013, Koji, Mechanics, Characterization, PZT actuator tested at LLO
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Test result of the PZTs by Valera and Ryan
PZT Length Angle
# [nm/V] [urad/um]
11 14.5 17.6
12 13.8 17.8
13 11.2 25.0
14 14.5 6.6
15 12.5 10.6
21 14.5 9.7
22 13.8 28.8
23 14.5 6.8 ==> Assembly #2
24 18.5 51.7 ==> Used for prototyping
25 17.1 13.8
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Mon Apr 8 11:29:08 2013, Koji, Optics, Characterization, Mirror/PZT Characterization links
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Mirror List
http://nodus.ligo.caltech.edu:8080/OMC_Lab/152
Mirror T measurement: |