 Thu Jan 10 18:37:50 2013, Koji, Optics, Characterization, Wedging of the PZTs 
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Yesterday I measured the thickness of the PZTs in order to get an idea how much the PZTs are wedged.
For each PZT, the thickness at six points along the ring was measured with a micrometer gauge.
The orientation of the PZT was recognized by the wire direction and a black marking to indicate the polarity. |
 Thu Aug 22 12:35:53 2019, Stephen, Optics, Characterization, Wedging of the debonded PZTs 2019 August
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Wedge and thickness measurements of PZTs 12 and 13 took place after debonding and cleaning - results are shown in the first image (handwritten post-it
format).
These thickness measurements seem to have come back thinner than previous measurements. It is possible that I have removed some PZT material |
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Thu Aug 29 11:51:49 2019, shruti, Optics, Characterization, Wedging of the debonded PZTs - Calculation
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Using the measurements of PZTs 12,13 taken by Stephen, I estimated the wedging angle and orientation following Section 2.3.1 of T1500060. The results
can be found in Attachment1 and is summarised as follows.
For PZT 12, PZT 13 respectively: |
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Fri Aug 23 11:11:44 2019, shruti, Optics, Characterization, Finding the curvature bottom
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I attempted to fit the data taken by Koji of the beam spot precession at the CCD in order to find the location of the curvature bottom in terms
of its distance (d) and angle () from the centre of the mirror. This was done using
the method described in a previous similar measurement and Section 2.1.3 of |
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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. |
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Mon Jul 1 12:38:49 2019, Koji, Optics, Characterization, A and M prisms perpendicularity measurement 6x
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[Stephen, Koji]
The perpendicularity of some of the A and M prisms were tested.
Results |
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Mon Jun 24 12:54:58 2019, Koji, Clean, General, HEPA BOOTH
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| https://www.airscience.com/purair-flow-laminar-flow-cabinets |
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Tue May 28 12:14:20 2019, Stephen, Optics, General, CM PZT Assembly Debonding of EP30-2 in Acetone 8x
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[LiyuanZ, StephenA]
Downs B119
Summary: Beginning on 20 May 2019, two CM PZT assemblies were soaked in Acetone in an effort to debond the EP30-2 bonds |
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Thu May 23 23:27:38 2019, Koji, Optics, Characterization, IGHQEX3000 high power test
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LaserComponents IGHQEX3000 (Cage B2: Serial# B1-23) was exposed to the beam with the optical power from 1.6mW to 332mW.
After each illumination, the dark current and the dark noise level were measured. Also the photo image of the PD surface was taken each time.
- No significant change of the dark current after each illumination. |
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Thu May 23 01:42:46 2019, Koji, Optics, Characterization, C30665 high power test
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An Excelitas C30665 PD with the cap removed (SN07 in Case H slot #2) was exposed to the beam with the optical power of 1.4mW to 334mW.
After each illumination, the dark current and the dark noise level were tested. Also the photo image of the PD surface was taken each time.
- No significant change of the dark current after each illumination. |
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Mon May 20 19:53:17 2019, Koji, Optics, Configuration, DCPD high power test
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We want to perform a damage test of OMC DCPDs with high power beam. The OMC DCPD is the 3mm InGaAs photodiodes with high quantum efficiency, delivered
by Laser Components.
The sites want to know the allowed input power during the OMC scan for beam mode analysis. The nominal bias voltage of the PDs is +12V. Therefore, |
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Wed May 22 07:31:37 2019, Koji, Optics, Configuration, Camera test (DCPD high power test)
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C30665 (3mm) camera test. The camera was Canon PowerShot G7X MkII. Exposure 1/15s, F 5.6, ISO 125, MF (~the closest), no zoom.
This image was taken before the beam illumination. Will tune the green lighting to have some gradient on the surface so that we can see any deformation
of the surface. |
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Thu May 16 12:41:28 2019, Chub, General, General, fire pillow found on optics table
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That is an expanding fire pillow, also known as firebrick. It is used to create a fire block where holes in fire-rated walls are made and prevents
lab fires from spreading rapidly to adjacent labs. I had to pull cable from B254 to our labs on either side during a rather narrow window of time.
Some of the cable holes are partially blocked, making it difficult to reach the cable to them. The cable is then just guided to the hole from a distance. |
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Wed May 15 19:07:53 2019, Koji, Clean, General, What is this???
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Suddenly something dirty emerged in the lab. What is this? It looks like an insulation foam or similar, but is quite degraded and emits a lot of particulates.
This does not belong to the lab. I don't see piping above this area which shows broken insulation or anything. All the pipes in the room
are painted white. |
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Thu May 9 18:10:24 2019, Koji, Optics, Characterization, OMC(004): Spot position scan / power budget
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(Now the CCD image is captured as a movie and the screen capture is easier!)
Various spot positions on CM1 and CM2 were tried to test how the transmission is dependent on the spot positions. CM1 has a
few bright spots while CM2 shows very dark scattering most of the case. Attachment 1 is the example images of one of the best alignment |
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Thu May 9 17:35:07 2019, Koji, Optics, General, Alignment strategy
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Notes on the OMC cavity alignment strategy
- x3=1.17 γ + 1.40 δ, x4=1.40 γ + 1.17 δ
- This means that the effect of the two curved mirrors (i.e. gouy phases) are very similar. To move x3 and x4 in common is easy, but to do differentially |
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Thu May 9 16:07:18 2019, Stephen, Mechanics, General, Improvements to OMC Bonding Fixture
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[Stephen, Koji]
As mentioned in eLOG 331, either increased thermal cycling or apparent improvements
in cured EP30-2 strength led to fracture of curved mirrors at unintended locations of bonding to the PEEK fixture parts. |
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Wed May 1 15:40:46 2019, Koji, Optics, Characterization, OMC(004): Spot positions and the scattering
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Tried a few things.
1. Replaced CM1 (PZT ASSY #10=M21+PZT#22+C12) with PZT ASSY #7 (=M1+PZT#13+C13)
We tried PZT ASSY #7 at the beginning and had the spots at almost at the top edge of the curved mirrors. As we found a particle on the bottom |
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Fri May 3 11:06:28 2019, Koji, Optics, Characterization, OMC(004): Spot positions and the scattering
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Experiment on 5/1
- CM1 right knob was moved 1div (10um) backward such that the spots were better centered on the mirrors
FM1 (A5): h=-0.2mm -> 0.4mm made the spot much darker but still it has a few scattering spots. |
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Thu Apr 25 15:05:19 2019, Joe, Optics, Characterization, Looking at PZT HOM spacing dependance and thinking about workflow
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[koji, joe]
The template or glass breadboard was wobbling, and we noticed that the caivty alignment became worse/better when it was pressed down. We saw
that it was the glass breadboard, so it was fixed into the transport fixture more securely. Now its alignement didn't change when it was pressed down. |
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Wed Apr 24 13:58:51 2019, Joe, Optics, Characterization, OMC power budget and UV Epoxy Bonding of BS1
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[koji,philip,joe,liyuan,stephen]
need to add spot positions.
Mirrors: PZT11,PZT22, A14, A5 |
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Tue Apr 23 10:21:12 2019, Joe, Optics, Configuration, Moving the spots to the centre of the curved mirrors
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[Koji,Philip, Liyuan, Joe]
CM1:
We moved the curved mirrors to these positions: |
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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 |
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Mon Apr 22 19:54:28 2019, Koji, General, , OMC(004): Spot positions at the end of Apr 22nd
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| |
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Sat Apr 20 00:50:12 2019, Koji, Optics, Characterization, OMC(004): Spot positions
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Similarly to OMC ELOG 349 the spot positions after the replacement of CM2 were measured
(Attachment 1)
Also, the spot positions after the realignment were measured. (Attachment 2) |
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Thu Apr 18 20:47:54 2019, Joe, Optics, , OMC initial alignment and locking
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[Joe, Phillip, Koji, Stephen]
*draft post, please add anymore info if I missed something*
made initial alignment of the cavity. To do this we used the periscope mirrors to aim the incoming beam at the centre of the |
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Fri Apr 19 11:34:19 2019, Koji, Optics, , OMC initial alignment and locking
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The spot on CM1 was found displaced by 3.4mm (horiz.) and 3.0mm (vert.) in the upper right direction looking from the face side.
The spot on CM2 was found displaced by 1.2mm (horiz.) and 1.8mm (vert.) in the upper left direction looking from the face side.
The drawing on the left side of the attachment shows the estimated misalignment when we think they all come from the curved |
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Fri Apr 19 09:35:28 2019, Joe, General, , Adjusting cavity axis, re-alignment of OMC and locking
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[koji,philip, joe, liyuan, steven]
*still need to add photos to post*
PZT 11 was removed and inspected for so dust/dirt on the bottom of the prism. We saw a spot. We tried to remove this with acetone, |
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Fri Apr 19 09:21:07 2019, Philip, Optics, , Cleaning of OMC optics
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ach[Joe, Phillip, Koji, Stephen]
Work from 17.04.2019
First contact cleaning of OMC optics |
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Wed Apr 17 10:30:37 2019, Philip, Optics, General, OMC optical set-up day 1
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[Joe, Koji, Liyuan, Philip, Stephen]
Work done on 16.04.2019
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Wed Apr 17 09:08:47 2019, Stephen, General, General, OMC(004): Unwrapping and preparing breadboard
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[Stephen, Philip, Koji, Joe]
Breadboard D1200105 SN06 was selected as described in eLOG 338. This log describes
unwrapping and preparation of the breadboard. |
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Tue Apr 16 23:11:43 2019, Koji, General, General, Borrowed items from the other labs
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Apr 16, 2019
Borrowed two laser goggles from the 40m. (Returned Apr 29, 2019)
Borrowed small isopropanol glass bottole from CTN. |
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Mon Apr 15 21:11:49 2019, Philip, Optics, Characterization, OMC(004): PZT testing for spare OMC
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[Koji, Philip]
Today we tested the functionality of the four remaining PZTs (11,12,13 and 22) . Each PZT was placed within a collimated 500um beam.
Roughly half of the beam was blocked by the PZT. The PZT and a PD then acted as shadow sensor. Each PZT was tested with 0 and |
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Tue Apr 16 11:36:36 2019, Koji, Optics, Characterization, OMC(004): PZT testing for spare OMC 9x
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Attachment 1: Shadow sensor setup for the PZT displacement test
Attachment 2: PZT endurance test. 4 PZTs were shaken at once.
Attachment 3~5: Function generator setup 100Hz, 3.5Vpp 1.75Voffset (meant be displayed for 50Ohm load) |
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Tue Apr 16 21:16:11 2019, Koji, Optics, Characterization, OMC(004): PZT testing for spare OMC
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After having dug into the past email, it turned out that these wires were the ones already replaced from the original teflonwires. The length of them
were confirmed to be ~19" (480mm).
Quote:
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Tue Apr 16 17:24:56 2019, Koji, Optics, Configuration, OMC(004): E Mirror selection
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We are going to use E6, E9, E11, and E14 for BS1, SM1, SM2, and SM3. They (and E18) are all very similar.
The attachment is the excerpt from T1500060 with some highlighting |
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Tue Apr 16 16:52:36 2019, Koji, Optics, Configuration, OMC(004): B Mirror selection
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We are going to use B6 for the DCPD BS (BS2), and B1 for the QPD BS (BS3). Their role can not be swapped.
B6 has the best loss among the available ones, while the perpendicularity is not so critical due to the short arm.
B1 has the OK perpendicularity, while the loss is also moderately good. |
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Tue Apr 16 16:40:26 2019, Koji, General, Configuration, OMC(004): A Mirror selection
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We are going to use A5 and A14 for FM1 and FM2. (The role of these two can be swapped)
The reason for the selection is the better perpendicularity among the available prisms.
A11 has the best perpendicularity among them. However, the T didn't match with the others. The pair of A5 and A14 has a good matching with |
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Tue Apr 16 16:35:09 2019, Koji, Optics, Configuration, OMC(004): Glass breadboard selection
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D1200105 SN006 was selected as the breadboard for OMC(004).
The reason is the best parallelism among the unused ones.
The attached is the excerpt from T1500060 with the #006 highlighted. |
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Sun Apr 14 23:58:49 2019, Koji, General, General, OMC(004): PZT sub-assembly post air-bake inspection
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[Koji Stephen]
(Friday afternoon) We retrieved the PZT sub-assemblies to the clean room.
We started removing the ASSYs from the fixtures. We noticed that some part of the glass and PZT are ripped off from the ASSY and stuck with the |
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Mon Apr 15 00:08:32 2019, Koji, General, General, OMC(004): PZT sub-assembly post air-bake inspection (Sub-assy #7) 6x
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Sub-ASSY #7
Probably the best glued unit among the four.
Attachment #1: Mounting Block SN001 |
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Mon Apr 15 00:39:04 2019, Koji, General, General, OMC(004): PZT sub-assembly post air-bake inspection (Sub-assy #8) 8x
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Sub-ASSY #8
Probably the best glued unit among the four.
Attachment #1: Mounting Block SN007 |
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Mon Apr 15 01:07:30 2019, Koji, General, General, OMC(004): PZT sub-assembly post air-bake inspection (Sub-assy #9) 7x
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Sub-ASSY #9
The most fractured unit among four.
Attachment #1: Mounting Block SN017 |
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Mon Apr 15 01:23:45 2019, Koji, General, General, OMC(004): PZT sub-assembly post air-bake inspection (Sub-assy #10)
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Sub-ASSY #10
Attachment #1: Mounting Block SN021
Attachment #2: PZT-Mounting Block bonding looks just excellent. |
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Thu Apr 11 21:22:58 2019, Koji, General, General, OMC(004): PZT sub-assembly air baking
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[Stephen Koji]
The baking of the PZT subassemblies was more complicated than we initially thought.
The four PZT subassemblies were placed in the air bake oven A. We meant to bake the assemblies with the ramp time of 2.5h, a plateau of 2h at |
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Thu Apr 11 21:22:26 2019, Koji, Mechanics, General, OMC(004): PZT sub-assembly gluing
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[Koji Stephen]
The four PZT sub-assemblies were glued in the gluing fixtures. There were two original gluing fixtures and two additional modified fixtures for
the in-situ bonding at the repair of OMC(002). |
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Thu Apr 11 12:15:31 2019, Koji, Mechanics, Configuration, PZT sub assy mirror orientations
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| |
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Wed Apr 10 19:22:24 2019, Koji, General, General, OMC(004): preparation for the PZT subassembly bonding
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Preparation for the PZT subassembly bonding (Section 6.2 and 7.3 of T1500060 (aLIGO OMC optical
testing procedure)
- Gluing fixture (Qty 4) |
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Thu Apr 11 10:54:38 2019, Stephen, General, General, OMC(004): preparation for the PZT subassembly bonding
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Quote:
Preparation for the PZT subassembly bonding (Section 6.2 and 7.3 of T1500060
(aLIGO OMC optical testing procedure) |
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Fri Apr 5 23:30:20 2019, Koji, General, General, OMC (002) repair completed
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OMC(002) repair completed
When the cable harness of OMC(004) is going to be assembled, the cable harness of OMC(002) will be replaced with the PEEK one. Otherwise, the
work has been done. |
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Fri Apr 5 20:50:54 2019, Koji, Optics, Characterization, OMC(002): QPD alignment
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QPD# QPD1 QPD2
Housing# #004 #008
Diode# #44 #46 |
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Fri Apr 5 01:08:17 2019, Koji, Optics, Characterization, OMC(002): DCPD / QPD alignment
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The beam height in the cavity became totally different from the previous one and the shims needed to be much thicker than before. This is probably because
of the alignment of the newly-glue curved mirror.
As the beam height is 2~2.5mm higher, two shims need to be stacked. The preliminary check of the heights using the alignment disks (dummy PDs) |
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Fri Apr 5 01:07:18 2019, Koji, Optics, Characterization, OMC(002): transmitted beam images
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There was a concern that the transmission from CM1 has additional fringes. The shape of the transmitted beams from CM1, CM2, and FM2 (main) werecaptured
with WinCamD.
Indeed CM1 and CM2 have the fringes, but it does not exist in the main transmission. So it seems that the fringes are associated with the curved |
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Thu Apr 4 20:07:39 2019, Koji, Supply, General, Purchase
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== Office Depot ==
Really Useful Box 9L x 6 (delivered)
Really Useful Box 17L x 5 (ordered 4/4) |
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Thu Mar 28 16:36:52 2019, Koji, Mechanics, Characterization, OMC(002) PZT characterization
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As performed in the ELOG 202, the PZTs of the OMC 002 were tested.
DC response was measured by sweeping each PZT with 0-150V triangular voltage at 11Hz. Acquire 0.2sec of the tie series using an oscilloscope
to get the PDH error, cavity transmission, and the sweep signal. |
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Tue Mar 19 17:30:25 2019, Koji, General, Characterization, OMC (002) Test items
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OMC #002 Optical tests
FSR measurement (done, 2019/1/8-9, 2019/4/1)
TMS measurement
(done, 2019/1/9)
TMS measurement (with DC voltage on PZTs) (done, 2019/1/10)
Cleaning |
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Sat Feb 2 20:35:02 2019, Koji, Optics, Characterization, Summary: OMC(002) HOM structure recalculation (after mirror replacement)
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OMC (002) after repair
History:Mirror replacement after the damage at H1. Measurement date 2019/1/10 |
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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 |
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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 |
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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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Fri Feb 1 12:52:12 2019, Koji, Mechanics, General, PZT deformation simulation
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A simple COMSOL simulation was run to see how the PZT deforms as the voltage applied.
Use the geometry of the ring PZT which is used in the OMCs - NAC2124 (OD 15mm, ID 9mm, H 2mm)
The material is PZT-5H (https://bostonpiezooptics.com/ceramic-materials-pzt) which |
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Sat Jan 12 22:49:11 2019, Koji, Optics, Characterization, PM-SM patch cable mode cleaning effect
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Mode cleaning capability of an optical fiber was measured. The conclusion is that the
leakage of the non-fiber mode to the fiber output is insignificant and also practically negligible.
The tested fiber was Thorlabs 5-m Polarization Maintaining Single-Mode fiber (P3-1064PM-FC-5, PM Patch Cable, PANDA, 1064 nm, FC/APC, 5m). |
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Thu Jan 10 20:45:00 2019, Koji, Optics, Characterization, PZT test cable
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As OMC SN002 already has the PZTs connected to the Mighty-Mouse connector, a test cable with a female mighty-mouse connector was made.
A small imperfection: When the cable was inserted to the connector shell, I forgot to mirror the pin out. Therefore the color and pin number
do not match. |