 Thu Aug 25 02:17:09 2016, Koji, Optics, Characterization, Inspection of the damaged CM1 (prev H1OMC)
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Initial inspection results by Calum, et al.
https://dcc.ligo.org/LIGO-E1600268 |
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Fri Sep 9 14:34:31 2016, Koji, General, General, Item lending
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To 40m
First Contact Kit by Calum
Class A Kapton sheets |
 Fri Sep 9 19:43:32 2016, Koji, Optics, General, D1102211 OMC Diode Mount Glass Block went to Downs
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| D1102211 OMC Diode Mount Glass Block (11pcs) have been given to Calum@Downs |
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Mon Nov 21 21:19:20 2016, Koji, Optics, General, LWE NPRO Laser / Input Optics / Fiber Coupling
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- About 1.5 month ago, an 700mW LWE NPRO has been brought to OMC Lab.
- The SOP can be found here.
- The base was made for the beam elevation of 3" height. Four 1" pedestals were attached to rise the beam elevation to 4". |
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Wed Dec 7 19:18:10 2016, Koji, Optics, General, LWE NPRO Laser / Input Optics / Fiber Coupling
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FIber Input Mount 132deg
Fiber output mount 275deg
-> 525mW P: 517mW S: 8mW extinction ratio: 0.016 |
Wed Dec 7 21:18:35 2016, Koji, General, General, OMC placed on the table / the beam roughly aligned 
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The OMC mode matching sled was fixed on the nominal part of the table. Then the OMC was located at the nominal position marked by three poles.
The input periscope was adjusted to have the input beam roughtly centered on the OMC QPDs. This made the beam from FM2 aligned to the missing
CM1, and the beam just went through the hole of the mounting prism. Very promising! |
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Thu Dec 8 21:17:09 2016, Koji, General, General, OMC placed on the table / the beam roughly aligned
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The OMC cavity was locked. The alignment was precisely adjusted. The mode matching was optimized by the lens positions. The reflection during the lock
is ~0.01 compared to the full reflection on non-resonance, meaning the mode matching is ~99%. The error signal was maximized (i.e. demod pahse was adjusted)
by sweeping the modulation frequency. Note that the EOM is broad band. The modulation freq chosen today was 34.6MHz. |
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Thu Jan 19 20:57:53 2017, Koji, Supply, General, Purchase
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Ordered:
Office Depot
v AA battery Qty. 24 |
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Thu Feb 16 17:23:12 2017, Koji, Supply, General, Purchase
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BNC Patch Panel
8x Amphenol Connex 112443 / Isolated BNC FEMALE TO FEMALE BULKHEAD ISOLATED ADAPTER - 50 ohm
http://www.newark.com/amphenol-rf/112443/bulkhead-adapter-bnc-jack-bnc/dp/99H4399
Hole
Diameter: 13mm (0.512") D width 12.10mm (0.477")
4x Amphenol RF 31-4803-75 (75Ohm)
http://www.newark.com/amphenol-rf/31-4803-75/bulkhead-adapter-bnc-jack-bnc/dp/50B8959
same |
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Tue Mar 28 21:04:27 2017, Koji, Electronics, Characterization, PDH amp 6x
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Attachment 1: PDH amp RF part (before the preamp was installed)
Attachment 2: RF-AF transmission
Attachment 3: Attachment 3: LO dependence |
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Tue May 16 19:05:18 2017, Koji, Optics, Configuration, OMC SN002 fix - temporary optics
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| Working on the SN002 OMC fix. Checked the inventory. I think I am using C8 mirror as the new temporary CM1 and PZT24 as the new temporary CM2. |
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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. |
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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. |
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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. |
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Fri Jun 23 01:58:11 2017, Koji, Optics, General, OMC #002 Repair - CM1 gluing 6x
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[Alena, Koji]
Jun 21: Alena and Koji worked on gluing of the CM1 mirror on the OMC breadboard #002. This
is an irregular procedure. Usually, the PZT mirror subassembly is prepared before the mounting prism is glued on the breadboard. In this |
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Fri Jun 23 10:55:07 2017, Koji, Optics, General, Dust layer on black glass beam dumps?
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I wondered why the black glass beam dumps looked not as shiny as before. It was in fact a layer of dusts (or contaminants) accumulated on the surface.
The top part of the internal surface of the black glass was touched by a piece of lens tissue with IPA. The outer surface was already cleaned. IPA
did not work well i.e. Required multiple times of wiping. I tried FirstContact on one of the outer surface and it efficiently worked. So I think the internal |
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Sat Jul 1 15:29:57 2017, Koji, Optics, General, Black glass cleaning / Final bonding for the emergency repair for OMC #002
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[Alena, Koji]
Report of the work on June 30.
1. Cleaning of the black glass beam dumps |
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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 |
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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. |
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Sat Jul 29 21:42:51 2017, Koji, Electronics, Characterization, PDH amp
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| The polarities indicated in the right circuits were opposite, obviously. |
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Fri Sep 8 15:14:05 2017, Koji, Facility, General, Preparation for the plumbing work 7x
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[Steve, Aaron, Koji]
We've finished the preparation for the forthcoming plumbing work on (nominally) Sept 16th Saturday.
We've covered most of the west side of the OMC lab with plastic sheets and wraps. |
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Mon Nov 27 20:24:24 2017, Koji, General, General, A former LHO PD (Trans) removed from the OMC #002 for the shipment to Stockholm 6x
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Attachment 1: The PD was removed from the transmission side of the OMC #002 (former LHO OMC - the one blasted by the optical pulse in
Aug 2016).
It was confirmed that the PD has the scribing mark saying "A". |
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Thu Feb 22 20:21:02 2018, Koji, Optics, Characterization, aLIGO EOM test
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| POSTED to 40m ELOG |
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Mon Apr 2 17:27:04 2018, Koji, Optics, Characterization, aLIGO EOM test
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| 2nd optical test http://nodus.ligo.caltech.edu:8080/40m/13725 |
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Sat May 5 22:51:04 2018, Koji, Optics, General, 3IFO EOM Optical test
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| The 3IFO EOM test performed at the 40m. Result: 40m ELOG 13819 |
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Tue May 15 19:53:45 2018, Koji, Optics, General, EOM Q comparison
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Qs' were estimated with a lorentzian function (eye fit)
Current LHO EOM (final version, modulation depth measurement 2018/4/5) |
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Wed May 30 16:40:38 2018, Koji, Mechanics, Characterization, EOM mount stability test
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| https://awiki.ligo-wa.caltech.edu/wiki/EOM_Mount_Stability |
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Wed May 30 17:44:23 2018, Koji, Optics, Characterization, 3IFO EOM surface check
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3IFO EOM dark microscope images courtesy by GariLynn and Rich
Attachment1/2: Hole #1
Attachment3/4: Hole #2 |
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Mon Jul 2 11:30:22 2018, Koji, Electronics, Characterization, 3IFO EOM impedance measurement
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[Rich Koji]
3IFO EOM (before any modification) was tested to measure the impedance of each port.
The impedance plot and the impedance data (triplets of freq, reZ, imZ) were attached to this entry. |
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Mon Jul 2 12:29:01 2018, Koji, Electronics, Characterization, Impedances of individual components (3IFO EOM)
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[Rich Koji]
The impedances of the individual components from the 3IFO EOM (before modification) were tested.
Each component was modeled by LISO. The LISO model (in PDF and txt) are attached at the end of the entry. |
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Wed Jul 4 18:30:51 2018, Koji, Electronics, Characterization, EOM circuit models
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The circuit models for the 3IFO EOM (before mods) were made using LISO.
Then the modification plan was made to make it a new LLO EOM.
Impedance data, LISO model, Mathematica files are zipped and attached at the end. |
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Thu Jul 26 20:57:07 2018, Koji, Electronics, Characterization, 9MHz port tuned impedance
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[Rich Koji]
The 9MHz port was tuned and the impedance was measured. |
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Tue Aug 7 15:43:12 2018, Koji, Electronics, Characterization, New LLO EOM stuffed
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[Rich, Dean, Koji]
Stuffed all inductors for the new LLO EOM. As the impedances were sensitive to the positions of the inductors in the housing, they were glued
with a glue gun. |
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Thu Aug 9 11:24:29 2018, Koji, General, Characterization, Modulation Index Test Setup at 40m Lab
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[Rich Koji]
The impedances of the new LLO EOM were measured with the beat note setup at the 40m PSL (as described in the previous ELOG entry.
At the target frequencies (9.1MHz, 24.1MHz, 45.5MHz, 118.3MHz), the modulation responses were (0.09, 2.9e-3, 0.053, 0.021) rad/V. |
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Wed Aug 29 11:06:30 2018, Koji, General, General, RF AM RIN and dBc conversion
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0. If you have an RF signal whose waveform is , the amplitude is constant and 1.
1. If the waveform |
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Sun Sep 23 19:42:21 2018, Koji, Optics, General, Montecarlo simulation of the phase difference between P and S pols for a modeled HR mirror
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[Koji Gautam]
With Gautam's help, I ran a coating design code for an HR mirror with the standard quarter-wave design. The design used
here has 17 pairs of lambda/4 layers of SiO2 and Ta2O5 (=34 layers) with the fused silica as the substrate to realize |
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Thu Jan 10 20:42:54 2019, Koji, Optics, Characterization, FSR / HOM Test of OMC SN002
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OMC SN002 = Former LHO OMC which CM1 was destroyed by the lock loss pulse in 2016. This OMC needs to be optically tested before storage.
The test items:
[done] FSR measurement with offset PDH locking (FM->AM conversion)
[done] FSR/finesse |
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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. |
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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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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 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 |
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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 20:35:02 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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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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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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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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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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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 20:50:54 2019, Koji, Optics, Characterization, OMC(002): QPD alignment
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QPD# QPD1 QPD2
Housing# #004 #008
Diode# #44 #46 |