 Sat Jan 19 20:47:41 2013, Koji, Optics, Characterization, Wedge measurement with the autocollimator 
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The wedge angle of the prism "A1" was measured with the autocollimator (AC).
The range of the AC is 40 arcmin. This means that the mirror tilt of 40arcmin can be measured with this AC.
This is just barely enough to detect the front side reflection and the back side reflection. |
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Tue Jan 22 11:10:25 2013, Koji, Facility, General, Eyeware storage and hooks for the face shields are installed
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| A carpenter has come to install the eyeware storage and hooks for the face shields. |
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Tue Jan 22 17:56:32 2013, Koji, Mechanics, General, Rotary stage selection
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Newport UTR80
Sensitivity: 4 arcsec
Graduations: 1 deg
Vernier: 1 arcmin
Fine travel range: 4 deg
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Thu Feb 7 21:35:46 2013, Koji, General, General, Dmass's loan of LB1005 / A2&C2 sent to Fullerton / First Contact @40m
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Dmass borrowed the LB1005 servo amp from the OMC lab.
It happened this week although it seems still January in his head. Got it back on Mar 24th
The A2 and C2 mirrors have been sent to Josh Smith at Fullerton for the scatterometer measurement. |
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Thu Feb 7 23:01:45 2013, Koji, Optics, Characterization, UV epoxy gluing test
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[Jeff, Yuta, Koji]
Gluing test with UV-cure epoxy Optocast 3553-LV-UTF-HM
- This glue was bought in the end of October (~3.5 months ago). |
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Thu Feb 21 18:44:18 2013, Koji, Optics, Configuration, Perpendicularity test
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Perpendicularity test of the mounting prisms:
The perpendicularity of the prism pieces were measured with an autocollimator.
Two orthogonally jointed surfaces forms a part of a corner cube. |
 Wed Feb 27 18:18:48 2013, Koji, Optics, Configuration, More perpendicularity test
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Mounting Prisms:
(criteria: 30arcsec = 145urad => 0.36mm spot shift)
SN Meas.(div) ArcSec Spec. |
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Fri Mar 1 23:06:15 2013, Koji, Optics, Configuration, More perpendicularity test final
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Perpendicularity of the "E" mirror was measured.
Mounting Prisms:
(criteria: 30arcsec = 145urad => 0.36mm spot shift) |
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Mon Feb 4 00:39:08 2013, Koji, Optics, Characterization, Wedge measurement with the autocollimator and the rotation stage
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Method:
Mount the tombstone prism on the prism mount. The mount is fixed on the rotation stage.
Locate the prism in front of the
autocollimator.
Find the retroreflected reticle in the view. Adjust the focus if necessary.
Confirm that the rotation of the |
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Wed Feb 6 02:34:10 2013, Koji, Optics, Characterization, Wedge measurement with the autocollimator and the rotation stage
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Measurement:
A6: α = 0.665 deg, β = +3.0 arcmin (1.5 div up)
A7: α = 0.635 deg, β =
0.0 arcmin (0.0 div up)
A8: α = 0.623 deg, β = - 0.4 arcmin (-0.2 div up)
A9: α = |
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Fri Mar 1 23:52:18 2013, Koji, Optics, Characterization, Wedge measurement with the autocollimator and the rotation stage
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Measurement:
E1: α = 0.672 deg, β = +0.0 arcmin (0 div up)
E2: α = 0.631 deg, β = - 0.3 arcmin
(-0.15 div down)
E3: α = 0.642 deg, β = +0.0 arcmin (0 div up)
E4: α = 0.659 deg, β |
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Tue Mar 5 19:37:00 2013, Zach, Optics, Characterization, eLIGO OMC visibility vs. power measurement details
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EDIT (ZK): Koji points out that (1 - Ti) should really be the non-resonant reflectivity of the aligned cavity, which is much closer to 1. However,
it should *actually* be the non-resonant reflectivity of the entire OMC assembly, including the steering mirror (see bottom of post). The steering mirror
has T ~ 0.3%, so the true results are somewhere between my numbers and those with (1 - Ti) -> 1. In practice, though, these effects are swamped by the |
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Wed Mar 6 23:24:58 2013, Zach, Optics, Characterization, eLIGO OMC visibility vs. power measurement details
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I found that, in fact, I had lowered the modulation depth since when I measured it to be 0.45 rads --> Psb = 0.1.
Here is the sweep measurement:
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Thu Mar 7 15:53:47 2013, Koji, Mechanics, General, OMC Transportation fixture, OMC PD/QPD mounts
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Thu Mar 14 17:06:21 2013, Koji, Mechanics, General, OMC SUS work @LLO
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EDIT (ZK): All photos on Picasa.
Also, I discovered that since Picasa was migrated to Google+ only,
you no longer have the option to embed a slideshow like you used to. Lame, Google. |
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Thu Mar 14 22:18:23 2013, Koji, General, General, New loans for the diode test
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ALL returned
Loan from ATF:
2 blue banana cables returned on
Jun 4, 2013 |
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Fri Mar 15 02:15:45 2013, Koji, Electronics, Characterization, Diode testing
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Diode testing
o Purpose of the measurement
- Test Si QPDs (C30845EH) for ISC QPDs Qty 30 (i.e. 120 elements) |
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Sun Mar 17 21:59:47 2013, Koji, Electronics, Characterization, Diode testing ~ DCPD
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- For the dark noise measurement, the lid of the die-cast case should also contact to the box for better shielding. This made the 60Hz lines almost completely
removed, although unknown 1kHz harmonics remains.
- The precise impedance of the setup can not be obtained from the measurement box; the cable in between is too long. The diode impedance should |
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Wed Mar 20 09:38:02 2013, Zach, Optics, Characterization, [LLO] OMC test bench modified
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For various reasons, I had to switch NPROs (from the LightWave 126 to the Innolight Prometheus).
I installed the laser, realigned the polarization and modulation
optics, and then began launching the beam into the fiber, though I have not coupled any light yet. |
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Sat Mar 23 02:32:23 2013, Koji, Facility, General, N2 cylinder delivered
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Preparation for ionized N2 blow
- 99.9998% N2 cylinder delivered (ALPHAGAZ 2 grade by AIR LIQUIDE) ALPHAGAZ
2 [PDF] |
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Sat Mar 23 02:41:00 2013, Koji, Optics, General, Black glass beam dumps for the first OMC
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Received black glass beam dumps from MIT
- gluing by EP30-2 looks pretty fine. Enough sturdy.
- some gap visible between the glass => incident angle should be considered so that the first beam does not exit from the gap |
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Sat Mar 23 13:34:14 2013, Koji, Optics, General, PZT assembly prototype glued
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Prototype PZT assembly
Motivation: |
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Sat Mar 23 16:36:15 2013, Koji, Electronics, Characterization, Diode QE measurement
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Quantum efficiencies of the C30665GH diodes were measured.
- The diode was biased by the FEMTO preamplifier.
- Diode Pin 1 Signal, Pin 2 +5V, Pin 3 open |
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Mon Mar 25 19:31:16 2013, Koji, Optics, General, OMC Top-side gluing
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[Koji Jeff Zach]
AAA
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Tue Mar 26 22:33:07 2013, Koji, General, General, Loan for the OMC building
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Loan from PSL Lab
- 300mm mirror with Ultima mount and pedestal
- Isopropanol small glass bottleReturned on Apr 12 2013. |
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Mon Mar 25 02:04:05 2013, Koji, General, General, OMC building plan / procedure ~ WB18
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WB 18 March
Diode test
Dark current / Dark noise / Impedance
Quantum Efficiency test (but with glass)
Diode given |
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Mon Mar 25 18:34:25 2013, Koji, General, General, OMC building plan / procedure ~ Mar 25 Mon
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25 March (Mon):
Inspect the test PZT assembly
=> Give it to Bob. (done)
Glue topside components |
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Wed Mar 27 20:54:45 2013, Koji, General, General, OMC building plan / procedure ~ Mar 26 Mon
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26 March (Tue):
- Curved mirror characterization (Koji, done)
- Input optics for the cavity locking (Zach) |
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Wed Mar 27 20:54:54 2013, Koji, General, General, OMC building plan / procedure ~ Mar 27 Wed
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27 March (Wed)
- AOM drift investigation (Lisa, Zach)
- Cavity input optics ~ Fiber coupling (Zach) |
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Wed Mar 27 20:55:10 2013, Koji, General, General, OMC building plan / procedure ~ Mar 28 Thu
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28 March (Thu):
Rebuild the bottom template in the lab
Place the bottom template on the OMC
Glue the PZTs on the mounting
prisms (x2)
Glue the curved mirrors on the PZTs (x2)
R&T measurement
Placing optics on the OMC breadboard |
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Mon Apr 1 03:13:41 2013, Koji, Optics, General, Failure of PZT-glass joints
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[Koji, Jeff, Zach, Lisa]
We glued a test PZT-mirror assembly last week in order to make sure the heat cure of the epoxy does not make any problem
on the glass-PZT joints. The assembly was sent to Bob for the heat treatment. We received the assembly back from Bob on Wednesday. |
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Mon Apr 1 03:23:48 2013, Koji, Optics, General, UV power calibration
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[Koji Lisa Jeff Zach]
Eric G bought a UV power meter from American Ultraviolet.
Our UV illuminator was calibrated by this power meter. |
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Mon Apr 1 10:28:03 2013, Koji, Mechanics, General, Additional UV blast for the top surface
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[Koji, Lisa, Jeff, Zach]
Jeffs concern after talking with the glue company (EMI) was that the UV blast for the top side was not enough. |
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Mon Apr 1 18:17:01 2013, Koji, Optics, General, Mirror curvature center test 6x
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Locations of the curvature minimum on the OMC curved mirrors have been measured.
Motivation:
When a curved mirror is misaligned, the location of the curvature center is moved. |
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Wed Apr 3 18:42:45 2013, Koji, Optics, General, EP30-2 gluing test
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EP30-2 gluing test
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Thu Apr 4 00:35:42 2013, Zach, Optics, Configuration, MMT installed on breadboard, periscope built
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[Koji, Zach]
We installed the MMT that matches the fiber output to the
OMC on a 6"x12" breadboard. We did this so that we can switch from the "fauxMC" (OMC mirrors arranged with standard |
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Thu Apr 4 01:35:04 2013, Koji, Optics, Characterization, Mode matching to the OMC cavity
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The fiber output was matched with the lenses on a small bread board.
The detailed configuration is found in the following elog link.
http://nodus.ligo.caltech.edu:8080/OMC_Lab/105 |
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Wed Apr 3 17:39:38 2013, Koji, Mechanics, Characterization, Calibration of the test PZTs before the glue test
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We want to make sure the responses of the PZT actuator does not change after the EP30-2 gluing.
A shadow sensor set up was quickly set-up at the fiber output. It turned out the ring PZTs are something really not-so-straightforward.
If the PZT was free or just was loosely attached on a plane by double-sided tape, the actuation response was quite low (30% of the spec). |
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Fri Apr 5 14:39:26 2013, Koji, Mechanics, Characterization, Calibration of the test PZTs after the heat cure
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We attached fused silica windows on the test PZTs. http://nodus.ligo.caltech.edu:8080/OMC_Lab/93
The glued assemblies were brought to Bob's bake lab for the heat cure. There they are exposed to 94degC heat for two hours (excluding ramp up/down
time). |
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Thu Mar 28 03:37:07 2013, Zach, Optics, Configuration, Test setup input optics progress
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[Lisa, Zach]
Last night (Tuesday), I finished setting up and aligning most of the input optics for the OMC characterization setup. See the diagram below, but
the setup consists of: |
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Fri Mar 29 08:55:00 2013, Zach, Optics, Configuration, Beam launched into fiber
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Quote:
Lisa and I concurred that it felt like we had converged to the optimum alignment and polarization, which would mean that the lack of |
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Thu Apr 4 23:44:52 2013, Koji, Optics, Configuration, Beam launched into fiber
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We had to move our flipper mirror to share the beam between Peter's setup and ours as our flipper is at the place where the ISS PD array base is supposed
to be!
There was no place to insert the flipper in the setup. We (Peter and Koji) decided to move the laser back for ~2". |
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Fri Apr 5 18:18:36 2013, Zach, Optics, Configuration, AOM probably broken
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Quote:
Then, I started to check the AOM path. I noticed that the 1st (or -1st) order beam is very weak. |
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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: |
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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 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 23:42:33 2013, Koji, Optics, Configuration, Fake OMC roughly aligned
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Mode matching:
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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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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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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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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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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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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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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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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 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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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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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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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 10 09:33:22 2013, Koji, Supply, General, COMSOL simulation on the glass bracket stress
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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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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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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 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 |