 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 |
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 |
 Thu Sep 27 20:19:15 2018, Aaron, Optics, General, Montecarlo simulation of the phase difference between P and S pols for a modeled HR mirror
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I started some analytic calculations of how OMC mirror motion would add to the noise in the BHD. I want to make some prettier plots, and am adding the
interferometer so I can also compute the noise due to backscatter into the IFO. However, since I've pushed the notebook I wanted to post an update.
Here's |
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Thu Nov 1 19:57:32 2018, Aaron, Optics, General, Montecarlo simulation of the phase difference between P and S pols for a modeled HR mirror
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I'm still not satisfied/done with the solution to this, but this has gone too long without an update and anyway probably someone else will have a
direction to take it that prevents me spinning my wheels on solved or basic questions.
The story will have to wait to be on the elog, but I've put it in the jupyter notebook. Basically: |
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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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Wed Aug 8 17:32:56 2018, Rich Abbott, General, Characterization, Modulation Index Test Setup at 40m Lab
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| Attached is a block diagram of the test setup used in the 40m lab to measure the modulation index of the IO modulator |
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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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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 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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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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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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Tue Jul 3 12:07:47 2018, Rich Abbott, Electronics, Characterization, Notes on 3rd IFO EOM
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| Attached please see my notes summarizing the models for the electrodes and inductors within the 3rd IFO EOM |
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Mon Jul 2 15:27:31 2018, Rich Abbott, Electronics, General, Work on EOM (3rd IFO unit)
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Koji, Rich
We took apart the unit removed from the 3rd IFO (Unit serial number aLIGO #3, XTAL 10252004) to see what makes it tick. Koji has done a
fine job of adding the plots of the impedance data to this log book. Attached are some details of the physical construction showing the capacitor |
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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 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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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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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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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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Thu May 3 21:45:58 2018, awade, General, Loan / Lending, Borrowed toaster oven
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| I’ve borrowed the black and decker toaster oven to dry some sonicated parts. It is temporarly located in the QIL lab. |
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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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Thu Nov 30 12:18:41 2017, Stephen, General, General, Preparation for Modal Testing on 4 December
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Norna Robertson, Stephen Appert || 29 Nov 2017, 2 pm to 4 pm || 227 Downs, CIT
We made some preparations for modal testing, but did not have enough time to make measurements. Below is an after-the-fact log, including some
observations and photos of the current state of the OMC bench. |
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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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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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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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Sat Jul 29 18:44:38 2017, rana, Electronics, Characterization, PDH amp
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| attachment 6: DCPD preamp looks like the opamp is wired for positive feedback? |
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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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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 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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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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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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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 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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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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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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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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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 |
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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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Tue Aug 23 23:36:54 2016, Koji, Optics, Characterization, Inspection of the damaged CM1 (prev H1OMC) 7x
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1. Calum and GariLynn checking the CM1 defect from the front side.
2. Same as above
3. Close up of the defect |
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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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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 |
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Mon Aug 15 10:09:10 2016, Koji, General, General, Prev H1 OMC shipped to CIT
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Previous H1 OMC shipped from LHO to CIT
https://ics-redux.ligo-la.caltech.edu/JIRA/browse/Shipment-8196 |
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Fri Aug 12 14:58:17 2016, Koji, General, Configuration, H1 OMC DCPD replacement
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Preparation of 3rd OMC for the use in H1
New DCPD(T) = B1-01
DCPD(T) = DCPDA: extracted and accomodated in CAGE-A SLOT1 |
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Fri Jul 22 22:24:05 2016, Koji, General, General, HQEPD inventory
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As of Jul 22, 2016
As of Aug 11, 2016
As of Aug 16, 2016 |
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Fri Jun 10 17:12:57 2016, Koji, General, Configuration, L1 OMC DCPD replacement
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New DCPD(T) = A1-23
DCPD(T) = DCPDB: extracted and accomodated in CAGE-G SLOT1
New DCPD(R) = A1-25 |
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Sat Mar 26 17:39:50 2016, Koji, Electronics, Characterization, HQEPD dark noise
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Dark noise measurement for 6 HQEPDs and 1 C30665. All of these showed sufficiently low dark current noise levels compared with the noise level of the
DCPD preamp. The measurement was limited by the input noise (ADC) noise of the FFT analyzer as the line noises were too big.
The measurement has been done with the transimpedance of 1e7. The bandwidth of the measurement was 50kHz. |
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Sat Mar 26 18:22:24 2016, Koji, Electronics, Characterization, Baking / Contamination tests of the PDs
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For the production of the aLIGO PDs, the following transfer of the PDs were carried out
A1-23 Cage A1 -> G1
A1-25 Cage A2 -> G2 |
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Tue Apr 5 18:22:40 2016, Koji, Electronics, Characterization, Baking / Contamination tests of the PDs
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Possible reduction of the QE was observed after air-bake at 75degC.
Yesterday I received Cage G from Bob for intermediate test of the PD performance after air bake but before vacuum bake.
This cage was prepared to be the production pair. |
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Tue Apr 5 21:20:15 2016, Koji, Electronics, Characterization, More dark noise measurement
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| All survived PDs have been measured. |
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Tue Apr 5 18:14:55 2016, Koji, General, Loan / Lending, QPD Lending Crackle
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Xiaoyue
QPD head
X-Z stage |
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Sat Mar 26 01:49:48 2016, Koji, Optics, Characterization, HQEPD QE
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Calibration of the transimpedance
Use KEITHLEY 2450 as a calibrated current source. Model 2450 has the current source accuracy of 0.020%+1.5uA at 10mA range. For 6mA current output,
the error is 3uA (0.05%). |
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Sun Mar 13 22:02:09 2016, Koji, Optics, Characterization, HQEPD QE measurement (direct comaprison)
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Direct comparison of the PD responsibities
We can expect 5% increase of the QE with the new PD.
P-pol 10deg incident |
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Sat Feb 20 19:11:22 2016, Koji, Electronics, Characterization, Dark current measurement of the HQE PD and other PDs
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Dark current of the HQE PD and other PDs were measured.
- The HQE PDs were loaded on the new PD transportation cages (Attachment 1)
The PDs are always shorted by a clean PD plugs. The PD element is still capped with Kapton seals. |
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Sun Mar 13 21:22:27 2016, Koji, Electronics, Characterization, Dark current measurement of the HQE PD and other PDs
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Transfered for RGA scan
B4 (C1-05) -> F1
C1 (C1-07) -> F2 |
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Sun Mar 6 02:13:28 2016, Koji, Optics, Characterization, PD glass reflections
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On friday, I removed a glass cover of a G30655 with a PD can cutter.
When a beam shoots a Perkin Elmer/Excelitas PD, we usually observe three reflections.
We always wonder what these are. |
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Thu Feb 18 21:08:32 2016, Koji, General, Loan / Lending, (all returned) Antonio loan
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| Antonio borrowed: Rich's PD cutter (returned), Ohir power meter(returned), Thorlabs power meter head, Chopper |
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Tue Dec 29 12:15:46 2015, Koji, General, General, Glasgow polarizer passed to Kate
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| The Glasgow polarizer was passed to Kate on Dec 17, 2015. |
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Fri Dec 18 15:33:24 2015, Koji, General, Loan / Lending, Loan from Rich
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Loan Record: I borrowed a PD can opener from Rich => Antonio Returned Sep 9, 2016
Tungsten Carbide Engraver (permanently given to the OMC lab)
KEITHLEY SOURCE METER + Laptop |
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Tue Dec 15 13:42:37 2015, Koji, Optics, Characterization, Dimensions / packaging of HQE PDs
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The dimensions of a high QE PDs was measured as well as the ones for C30665. (Attachment 4, Unit in mm)
They seemed to be very much compatible.
The PDs came with the designated case (Attachment 1). The bottom of the case has a spongy (presumably |
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Tue Dec 15 13:39:13 2015, Koji, Electronics, Characterization, Phase noise measurement of aLIGO EOM drivers
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This measurement has been done on Dec 1st, 2015.
The phase noise added by the EOM driver was tested.
The test setup is depicted in the attached PDF. The phase of the RF detector was set so that the output is close to zero crossing as much as |
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Tue Dec 15 13:38:34 2015, Koji, Electronics, Characterization, EOM Driver linearity check
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Linearity of the EOM driver was tested. This test has been done on Nov 10, 2015.
- Attachment 1: Output power vs requested power. The output start to deviate from the request above 22dBm request.
- Attachment 2: Ctrl and Bias voltages vs requested power. This bias was measured with the out-of-loop channel. |
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Tue Sep 8 11:18:10 2015, Koji, Optics, Characterization, PBS Transmission measurement
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Motivation: Characterize the loss of the Calcite Brewster PBS.
Setup: (Attachment 1)
- The beam polarization is rotated by an HWP |
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Wed Sep 9 01:58:34 2015, Koji, Optics, Characterization, PBS Transmission measurement
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Calcite Brewster PBS Continued
The transmission loss of the Calcite brewster PBS (eLIGO squeezer OFI) was measured with different conditions.
The measured loss was 3600+/-200ppm. (i.e. 900+/-50 ppm per surface) |
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Thu Sep 10 04:03:42 2015, Koji, Optics, Characterization, More polarizer optics measurement (Summary)
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Brewster calcite PBS (eLIGO Squeezer OFI)
Loss L = 3600 +/- 200ppm
Angular dependence: Attachment 1 |
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Wed Sep 23 17:49:50 2015, Koji, Optics, Characterization, More polarizer optics measurement (Summary)
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For the Glasgow PBS, the measurement has been repeated with different size of beams.
In each case, the PBS crystal was located at around the waist of the beam.
Otherwise, the measurement has been done with the same way as the previous entries. |