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Entry  Wed Aug 27 23:13:13 2014, Koji, Optics, Characterization, Collection of the power budgetting info 
L1 OMC Cavity power budget
H1 OMC Cavity power budget
3IFO OMC Cavity power budget
    Reply  Tue Sep 9 20:59:19 2014, Koji, Mechanics, Characterization, Structural mode analysis for the PZT mirror 6x
Structural analysis of the PZT mirror with COMSOL.
Inline figures: Eigenmodes which involves large motion of the tombstone. In deed 10kHz mode is not the resonance of the PZT-mirror joint,
but the resonance of the tombstone.
Entry  Sat Jan 17 11:40:04 2015, Koji, General, General, 3rd OMC completed 
Jan 15, 2015 3rd OMC completed

The face caps of the DCPD/QPD cables were installed (Helicoils inserted)
PD7&10 swapped with PD11(for DCPD T) and PD12(DCPD R).
    Reply  Fri Jan 30 19:31:08 2015, Koji, General, General, Item lending 


    Reply  Tue Feb 3 18:23:49 2015, Koji, General, General, Item lending 
- The laser was removed and shipped to LHO today.

- UV illuminator / fused silica fiber light guide / UV power meter / UV face shield (Qty 2) will be shipped to MIT.
They are CIT properties except for the illuminator.
    Reply  Wed Feb 4 20:07:24 2015, Koji, General, General, Item lending C30140_1.JPGC30140_2.JPGC30141.JPGC30142.JPGC30143.JPG
Shipment to MIT (L. Barsotti, J. Miller)

1. UV Illuminator (LESCO Super Spot MK III)

2. UV Power meter (American Ultraviolet AIB1001) Caltech property C30140
Entry  Wed Feb 18 21:51:23 2015, Koji, General, General, Notes on OMC Transportation Fixtures & Pelican 
LLO has one empty OMC transportation fixture.

LHO has one empty OMC transportation fixture.

LHO has one OMC transportation fixture with 3IFO OMC in it.
Entry  Wed Jul 15 22:23:17 2015, Koji, Electronics, AM Stabilized EOM Driver, E1400445 first look IMG_20150714_195534852.jpgIMG_20150714_195227746_HDR.jpg
This is not an OMC related and even not happening in the OMC lab (happening at the 40m), but I needed somewhere to elog...

E1400445 first look

DCC E1400445
    Reply  Sat Jul 18 11:37:21 2015, Koji, Electronics, AM Stabilized EOM Driver, D0900848 power board ~ oscillation issue solved 6x
Power Supply Board D0900848 was oscillating. Here is the procedure how the issue was fixed.

PCB schematic: LIGO DCC D0900848

0. Extracting the power board.
    Reply  Tue Jul 21 20:20:12 2015, Koji, General, General, Item lending 
Kate (ATF)

- 4ch color oscilloscope (Tektronix)

- Chopper controller
    Reply  Wed Jul 22 09:43:01 2015, Koji, Electronics, AM Stabilized EOM Driver, Power supply test of the EOM/AOM Driver 
Serial Number of the unit: S1500117
Tester: Koji Arai
Test Date: Jul 22, 2015 
    Reply  Wed Jul 22 10:15:14 2015, Koji, Electronics, AM Stabilized EOM Driver, RF test of the EOM/AOM Driver S1500117 
7) Make sure the on/off RF button works,
=> OK

8) Make sure the power output doesn't oscillate,
    Reply  Sat Jul 25 17:24:11 2015, Koji, Electronics, AM Stabilized EOM Driver, RF test of the EOM/AOM Driver S1500117 7x
(Calibration for Attachment 5 corrected Aug 27, 2015)

Now the test procedure fo the unit is written in the document https://dcc.ligo.org/LIGO-T1500404

And the test result of the first unit (S1500117) has also been uploaded to DCC https://dcc.ligo.org/LIGO-S1500117
    Reply  Tue Jul 28 18:36:50 2015, Koji, Electronics, AM Stabilized EOM Driver, RF test of the EOM/AOM Driver S1500117 IMG_20150727_214536773_HDR.jpgEOM_Driver_DAQ_TF_test.pdfEOM_Driver_Mon_PSD.pdf
Final Test Result of S1500117: https://dcc.ligo.org/LIGO-S1500117

After some staring the schematic and checking some TFs, I found that the DAQ channels for MON2 have a mistake in the circuit.
Differential driver U14 and U15 of D0900848 are intended to have the gain of +10 and -10 for the pos and neg outputs.
Entry  Mon Aug 10 02:11:47 2015, Koji, Electronics, AM Stabilized EOM Driver, RF AM Measurement Unit E1500151 IMG_20150803_223403975.jpgIMG_20150803_221210816_HDR.jpgIMG_20150803_223420267.jpg
This is an entry for the work on Aug 3rd.

LIGO DCC E1500151

Power supply check
    Reply  Mon Aug 10 11:39:40 2015, Koji, Electronics, AM Stabilized EOM Driver, RF AM Measurement Unit E1500151 
Entry for Aug 6th, 2015

I faced with difficulties to operate the RF AM detectors.

I tried to operate the RF AM detector. In short I could not as I could not remove the saturation of the MON outputs, no matter how jiggle the
    Reply  Mon Aug 10 11:57:17 2015, Koji, Electronics, AM Stabilized EOM Driver, RF AM Measurement Unit E1500151 screen_shot.png
Spending some days to figure out how to program CPLD (Xilinx CoolRunner II XC2C384).

I learned that the JTAG cable which Daniel sent to me (Altium JTAG USB adapter) was not compatible with Xilinx ISE's iMPACT.

I need to use Altium to program the CPLD. However I'm stuck there. Altium recognizes the JTAG cable but does not see CPLD. (Attachment 1)
    Reply  Mon Aug 10 12:09:49 2015, Koji, Electronics, AM Stabilized EOM Driver, RF AM Measurement Unit E1500151 IMG_20150809_215628585_HDR.jpg
Still suffering from a power supply issue!

I have been tracking the issues I'm having with the RF AM detector board.

I found that the -5V test point did not show -5V but ~+5V! It seemed that this pin was not connected to
Entry  Thu Aug 20 01:35:01 2015, Koji, Electronics, General, OMC DCPD in-vacuum electronics chain test OMC_DCPD_Chain.pdfOMC_DCPD_Transimpedance.pdf
We wanted to know the  transimpedance of the OMC DCPD at high frequency (1M~10M).
For this purpose, the OMC DCPD chain was built at the 40m. The measurement setup is shown in Attachment 1.

- As the preamp box has the differential output (pin1 and pin6 of the last DB9), pomona clips were used to measure the transfer functions
    Reply  Wed Aug 26 11:31:33 2015, Koji, Electronics, General, OMC DCPD in-vacuum electronics chain test OMC_DCPD_OutputNoise.pdf
The noise levels of the output pins (pin1/pin6) are measured. Note that the measurement is done with SE. i.e. There was no common mode noise rejection.
    Reply  Fri Aug 28 01:08:14 2015, Koji, Electronics, AM Stabilized EOM Driver, RF AM Measurement Unit E1500151 ~ Calibration RFAM_detector_calib.pdfRFAM_detector_calib_spectra.pdf
Worked on the calibration of the RF AM Measurement Unit. 

The calibration concept is as follows:

Generate AM modulated RF output
Measure sideband amplitude using a network anayzer (HP4395A). This gives us the SSB
    Reply  Fri Aug 28 02:14:53 2015, Koji, Electronics, AM Stabilized EOM Driver, RF AM Measurement Unit E1500151 ~ 37MHz OCXO AM measurement OCXO_AM_noise.pdf
In order to check the noise level of the RFAM detector, the power and cross spectra for the same signal source
were simultaneously measured with the two RFAM detectors.

As a signal source, 37MHz OCXO using a wenzel oscillator was used. The output from the signal source
Entry  Sun Sep 6 16:50:51 2015, Koji, Electronics, General, Unit test of the EOM/AOM Driver S1500118 P9037810.JPGRF_AM_spectra.pdf
TEST Result: S1500118

Additional notes

- Checked the power supply. All voltages look quiet and stationary.
    Reply  Tue Sep 8 10:55:31 2015, Koji, Electronics, AM Stabilized EOM Driver, RF AM Measurement Unit E1500151 ~ 37MHz OCXO AM measurement 
Test sheet: https://dcc.ligo.org/LIGO-E1400445

Test Result (S1500114): https://dcc.ligo.org/S1500114
Entry  Tue Sep 8 11:18:10 2015, Koji, Optics, Characterization, PBS Transmission measurement setup.JPGCaF2Prism.jpgCaF2Prism2.JPG
Motivation: Characterize the loss of the Calcite Brewster PBS.

Setup: (Attachment 1)

- The beam polarization is rotated by an HWP
    Reply  Wed Sep 9 01:58:34 2015, Koji, Optics, Characterization, PBS Transmission measurement 
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)
    Reply  Thu Sep 10 04:03:42 2015, Koji, Optics, Characterization, More polarizer optics measurement (Summary) eLIGO_PBS.pdfHWP.pdfTFP.pdfGlasgow_PBS.pdf
Brewster calcite PBS (eLIGO Squeezer OFI)

Loss L = 3600 +/- 200ppm
Angular dependence: Attachment 1
    Reply  Wed Sep 23 17:49:50 2015, Koji, Optics, Characterization, More polarizer optics measurement (Summary) Glasgow_PBS_spotsize.pdf
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.
Entry  Tue Dec 15 13:38:34 2015, Koji, Electronics, Characterization, EOM Driver linearity check Output_linearity.pdfCtrl_Bias.pdf
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.
Entry  Tue Dec 15 13:39:13 2015, Koji, Electronics, Characterization, Phase noise measurement of aLIGO EOM drivers phase_noise.pdfphase_noise_9MHz.pdf
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
Entry  Tue Dec 15 13:42:37 2015, Koji, Optics, Characterization, Dimensions / packaging of HQE PDs PC147842.jpgPC147846.jpgPC147848.jpgHQEPD_dimension.pdf
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
Entry  Fri Dec 18 15:33:24 2015, Koji, General, Loan / Lending, Loan from Rich 
Loan Record: I borrowed a PD can opener from Rich => Antonio Returned Sep 9, 2016

Tungsten Carbide Engraver (permanently given to the OMC lab)

Entry  Tue Dec 29 12:15:46 2015, Koji, General, General, Glasgow polarizer passed to Kate 
The Glasgow polarizer was passed to Kate on Dec 17, 2015.
Entry  Thu Feb 18 21:08:32 2016, Koji, General, Loan / Lending, (all returned) Antonio loan 
Antonio borrowed: Rich's PD cutter (returned), Ohir power meter(returned), Thorlabs power meter head, Chopper
Entry  Sat Feb 20 19:11:22 2016, Koji, Electronics, Characterization, Dark current measurement of the HQE PD and other PDs P2197992.jpgPD_dark_current.pdfPD_dark_current_others.pdf
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.
Entry  Sun Mar 6 02:13:28 2016, Koji, Optics, Characterization, PD glass reflections P3048124.JPGP3048125.JPG
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.
    Reply  Sun Mar 13 21:22:27 2016, Koji, Electronics, Characterization, Dark current measurement of the HQE PD and other PDs 
Transfered for RGA scan

B4 (C1-05) -> F1
C1 (C1-07) -> F2
Entry  Sun Mar 13 22:02:09 2016, Koji, Optics, Characterization, HQEPD QE measurement (direct comaprison) 
Direct comparison of the PD responsibities

We can expect 5% increase of the QE with the new PD. 

P-pol 10deg incident
Entry  Sat Mar 26 01:49:48 2016, Koji, Optics, Characterization, HQEPD QE QE1.pngQE2.png
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%).
Entry  Sat Mar 26 17:39:50 2016, Koji, Electronics, Characterization, HQEPD dark noise PD_dark_current.pdf
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.
    Reply  Sat Mar 26 18:22:24 2016, Koji, Electronics, Characterization, Baking / Contamination tests of the PDs 
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
Entry  Tue Apr 5 18:14:55 2016, Koji, General, Loan / Lending, QPD Lending Crackle 

QPD head
X-Z stage
    Reply  Tue Apr 5 18:22:40 2016, Koji, Electronics, Characterization, Baking / Contamination tests of the PDs QE_after_air_bake.pdf
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.
    Reply  Tue Apr 5 21:20:15 2016, Koji, Electronics, Characterization, More dark noise measurement PD_dark_current.pdf
All survived PDs have been measured.
Entry  Fri Jun 10 17:12:57 2016, Koji, General, Configuration, L1 OMC DCPD replacement 
New DCPD(T) = A1-23
DCPD(T) = DCPDB: extracted and accomodated in CAGE-G SLOT1

New DCPD(R) = A1-25
Entry  Fri Jul 22 22:24:05 2016, Koji, General, General, HQEPD inventory 
As of Jul 22, 2016
As of Aug 11, 2016
As of Aug 16, 2016
Entry  Fri Aug 12 14:58:17 2016, Koji, General, Configuration, H1 OMC DCPD replacement  
Preparation of 3rd OMC for the use in H1

New DCPD(T) = B1-01
DCPD(T) = DCPDA: extracted and accomodated in CAGE-A SLOT1
Entry  Mon Aug 15 10:09:10 2016, Koji, General, General, Prev H1 OMC shipped to CIT 
Previous H1 OMC shipped from LHO to CIT

Entry  Mon Aug 22 12:58:16 2016, Koji, General, General, UV bond samples -> Garilynn 
- 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
Entry  Tue Aug 23 23:36:54 2016, Koji, Optics, Characterization, Inspection of the damaged CM1 (prev H1OMC) 7x
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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