[Koji, Zach]

Tonight, we locked the "fauxMC". We obtained a visibility of >99%.

Koji had aligned it roughly last night, but we wanted to have a couple steering mirrors in the path for this practice cavity (the periscope mirrors will serve this function in the real setup), so we marked the alignment with irises and installed two extra mirrors.

After obtaining flashes with the WinCam placed at the output coupler, we removed the WinCam and put a CCD camera at one of the curved mirror transmissions and used this to get a strong TEM₀₀ flash. Then, we installed the REFL PD/CCD, swept the laser PZT and optimized the alignment by minimizing the REFL dips. Finally, we connected the RF electronics and locked the cavity with the LB box. We used whatever cables we had around to trim the RF phase, and then Koji made some nice SMA cables at the 40m.

One thing we noticed was that we don't have enough actuation range to keep the cavity locked for very long---even with the HV amp (100V). We are going to offload to the NPRO temperature using an SR560 or pomona box circuit. We may also make an enclosure for the cavity to protect it from the HEPA blasting.

Tomorrow, after we do the above things, we will practice measuring the transmission, length (FSR) and mode spectrum of the cavity before moving on to the real McCoy.

L1 OMC

Cavity Mirrors

FM1 (input coupler): A8
FM2 (output coupler): A7
CM1 (curved mirror close to FM1): C6
CM2 (curved mirror close to FM2): C5

DCPD path

BS3 (BS for DCPDs): B5 B7

QPD path

BS1 (input steering): E10
SM1 (steering mirror next to BS1): E12
BS2 (BS for QPD path): B3
SM2 (steering mirror next to BS2): E4
SM3 (steering mirror next to SM2): E16

- QPD mount aligned, QPD output checked
  The spots are with 100um from the center of the diodes. [ELOG Entry (2nd photo)]

- TMS/FSR dependence on the PZT V
  Shows significant dependence on the PZT voltages
  It seems that the curvartures get longer when the voltages are applied to the PZTs.
  The effect on these two PZTs are very similar. The dependence is something like
  (TMS/FSR) ~ 0.219 - 1e-5 V
  May cause resonance of the higher-order modes (like 13th order of the 45MHz sidebands) at a specific range of the PZTs.
  We can't change anything any more, but the impact needs to be assessed

- DC response of the PZTs [ELOG Entry]
  PZT voltages were swept. Observed multiple fringes during the sweep.
  The data to be analyzed.

- AC response of the PZTs [ELOG Entry]
  PZT1 and PZT2 well matched. The first resonance at 10kHz.

- Open loop TF of the servo
  The UGF more than ~30kHz.

- Cleaning of the main optics with First Contact
  Done. Visible scattering seen with an IR was reduced, but still exist.
  All four cavity mirrors have about the same level of scattering.
  Each scattering is a group of large or small bright spots.
  It's actually a bit difficult to resolve the bright spots with the IR viewer.

- Raw transmission: i.e. Ratio between the sum of the DCPD paths and the incident power
  May 8th (before the baking):      0.918
  May 8th (First Contact applied): 0.940 (improved)
  Jun 2nd (after the baking):         0.927 (worse)
  Jun 2nd (First Cotact applied):   0.964 (improved)

- TMS/FSR/Finesse change before/after cleaning [ELOG Entry]
  Just a small change from the parameters before the bake.
  No quantitative difference.

  Method:
  BB EOM produces the AM sidebands together with the PM sidebands.
  Ideally, the PM sidebands does not produce the signal at the transmission, the output is dominated by the AM component.
  This is only true when there is no lock offset. In reality the curve is contaminated by the PM-AM conversion by the
  static offset or dynamic deviation of the locking point. So I had to take the central part of the TF and check the
  dependence of the fit region and the finesse.

  Before the cleaning: Finesse 396.9
  After the cleaning: Finesse 403.8

To Do

- Placement of the DCPD housings
- Through-put test with DCPDs
- Transmission dependence on the incident power
  (although the max incident is limited to ~35mW)

- Application of the first contact for the surface protection

OMC(002)

Cavity Mirrors

FM1 (input coupler): A9
FM2 (output coupler): A13
CM1 (curved mirror close to FM1): C9 (PZT ASSY #6 /  M6 /PZT21/C9)
CM2 (curved mirror close to FM2): C4 (PZT ASSY #4 / M11/PZT25/C4)

DCPD path

BS3 (BS for DCPDs): B10

QPD path

BS1 (input steering): E3
SM1 (steering mirror next to BS1): E5
BS2 (BS for QPD path): B9
SM2 (steering mirror next to BS2): E1
SM3 (steering mirror next to SM2): E2

[Koji, Jeff]

Background

In response to the failure of one of the PZTs on L1OMC (LLO:8366), we have been taking place an endurance test of
the four PZT sub-assemblies in prior to their being glued on the glass breadboard.

According to the technical note by Noliac, the common mode of PZT failure is degradation of the impedance
due to cyclic actuation (like 10^7 times) with over voltage. Therefore our procedure of the test to actuate the PZTs
at least 10^7 times with half voltage of the nominal operating voltage (i.e. nominal 200V) and check the degradation
of the impedance.

Driving signal

For the driving of the PZT, a thorlabs HV amp is used. A source signal of 3.5Vpp with an offset of 1.7V is produced
by DS345 function generator. This signal turns to a sinusoidal signal between 0 and 100V in conjunction with the gain
of 15 at the HV amp.

The maximum driving frequency is determined by the current supply limit of the HV amp (60mA). The capacitance
of each PZT is 0.47uF. If we decide to cycle the signal for 4 PZTs in parallel, the maximum frequency achievable
without inducing voltage drop is 100Hz. This yields the test period of 28hours in order to achive 10^7 cycles.

Initial impedance diagnosis

To check the initial state of the PZTs, a DC voltage of 100V was applied via 1kOhm output resistance.
(Note that this output resistance is used only for the impedance test.)
For each PZTs, both side of the resister showed 99.1V for all measurement by a digital multimeter.
Assuming the minimum resolution (0.1V) of the multimeter, the resistance of each PZT was more than 1MOhm before
the cycling test.

Failure detection

In order to detect any impedance drop of the PZTs, the driving signal is monitored on the oscilloscope via a 1:10 probe.
If there is any significant impedance drop, the driver can't provide the driving current correctly. This can be found
by the deviation of the driving voltage from the reference trace on the oscilloscope (below).

Temperature rise

Because of the loss angle of the PZT capacitance, heating of the PZTs is expected. In order to check the temperature rise,
an IR Viewer (FLIR) was used. We did not take care of careful calibration for the PZT emissibity as what we want was a
rough estimation of the temperature.

Before the driving (LEFT) and at the equilibrium (RIGHT)

The temperature change of the PZT was tracked for an hour (below). Fitting of the points indicated that the temperature rise is 2.3degC and the
time constant of 446 sec. This level of temperature rise is totally OK. (Note that the fitting function was T = 27.55 - 2.31 Exp[-t/446.])

Results

DAY1:

Start driving
20:27 25.2 degC, status OK
20:33 26.7 degC, status OK
20:41 26.9 degC, status OK
20:48 27.6 degC, status OK
20:54 27.4 degC, status OK
21:10 27.4 degC, status OK
21:37 status OK
Stop driving

70 minutes of driving (i.e. 4.2x10^5 cycles) => no sign of degradation

DAY2:

Start driving
14:15, 24.5 degC, status OK
14:17, 26.0 degC, status OK
14:24, 27.0 degC, status OK
14:40, 26.8 degC, status OK
14:50, 26.8 degC, status OK
15:30, 26.8 degC, status OK
15:55 status OK
17:40 status OK
21:00 status OK (2.43Mcycles + 0.42Mcycles = 2.85Mcycles)
1d+12:00 status OK (7.83Mcycles + 0.42Mcycles = 8.25Mcycles)
1d+15:00 status OK (8.91Mcycles + 0.42Mcycles = 9.33Mcycles)
1d+18:40 status OK (10.23Mcycles + 0.42Mcycles = 10.65Mcycles)
Stop Driving

After 10.65Mcycles no sign of degradationwas found.

The PZT tests were finished with the conclusion that the PZT won't be damaged with our expected usage.

This is another test of the PZTs to make sure small (~10V) reverse voltage does not break the PZTs.

Background

At the site, we decided to use one of the PZT, which is still alive, for the HV and LV actuation.
The HV actuation is limited to 0 to 100V while the LV actuation is 10Vdc with 1Vpp fast dithering.
This means that a reverse voltage upto 10.5V will be applied to the PZT at the worst case.

From the technical note this level of reverse voltage does not induce polarization of the PZT.
The test is to ensure the PZT is not damaged or degraded by this small reverse voltage.

Method

HV drive: Thorlabs HV amp (G=15) driven with DS345 function generator (3.5Vpp+1.7Vdc, 0.1Hz)
=> 0-100V @0.1Hz
=> The hot side of the potential is connected to the positive side of the PZT

LV drive: Phillips function generator (1Vpp+9.5Vdc@1kHz)
The driving frequency is limited by the current output of the function generator.
=> The hot side of the potential is connected to the negative side of the PZT

These drives shares the common ground.

Tests

Testing with spare PZTs 

Started @19:23 (Aug 23)
Stopped @20:15+2d (Aug 25, duration 48h52m)
17600cycles for the 0.1Hz drive.
176Mcycles for the 1kHz drive.

Checked the impedances of PZT1 and PZT2.

Apply 100Vdc via a 1kOhm resister, 0V detected across the 1kOhm resister
This is equivalent to the resistance of 1MOhm.

Testing with the PZT subassemblies

Started shaking of the four PZT assemblies @20:20 (Aug 25)
No impedance change observed @11:10+1d
No impedance change observed @15:30+1d
Stopped shaking of the four PZT assemblies @XXXX (Aug 26)

Wiring for the test

New DCPD(T) = A1-23
DCPD(T) = DCPDB: extracted and accomodated in CAGE-G SLOT1

New DCPD(R) = A1-25
DCPD(R) = DCPDA: extracted and accomodated in CAGE-G SLOT2

Preparation of 3rd OMC for the use in H1

New DCPD(T) = B1-01
DCPD(T) = DCPDA: extracted and accomodated in CAGE-A SLOT1

New DCPD(R) = B1-16
DCPD(R) = DCPDB: extracted and accomodated in CAGE-A SLOT2

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.

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.

- The trans RF PD was aligned first to the leakage beam. It turned out that this signal is too weak. Then the PD was aligned to one of the main OMC transmission. For this purpose, the OMC DCPD (T) was removed from the OMC breadboard.

- It seems that there is a significant amount of RF AM from the EOM. I suspect it is associated with the residual S-pol and birefringence of the steering mirrors (45deg HR). But the HWP at the output of the Faraday is fixed on the Faraday body with a screw and cumbersome for fine adjustment. A PBS and an HWP are added right before the EOM. This made the fiber coupler slightly misaligned. I suppose this new setup still has S&P on the fiber too. Thus, readjustment of the fiber rotations at the input is necessary.

Next step

- Input power to the fiber should be determined before the EOM. Otherwise, touching the HWP before the EOM causes too much power change at the optics of the OMC side.

- Precise adjustment of the RFAM is still necessary.

- The OMC curved mirror should be held by the new fixture.

- Check the beam spots

- Measure cavity parameters. (transmission/FSR/HOM/etc)

==> Then the curved mirror and the PZT will be glued on the prism

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.

- The input/output fiber couplers were adjusted to have the maximum transmission through the PBS right before the OMC.
- The HWP on the output side of the faraday was adjusted to have ~40mW input to the OMC.

Then, the OMC curved mirror is now held by the new in-situ gluing fixture instead of the conventional fixture attached upside down.
The OMC was ocked again and the input alignment was adjutsed. The fixture is blocking the QPD path, so it's not possible to confirm the proper alignment of the cavity (w.r.t. the QPD paths).

The precise positions of the spots could not be confirmed as the battery of the IR viewer was empty. Quick check of the spots by the card tells that the spot on the CM2 (PD side) is slightly too close to FM2 (output coupler). I wonder if this could be solved by rotating the curved mirror.

Otherwise everything look good. Let's try to glue the curved mirror tomorrow.

Note: Spot on CM2 is too close to the edge of the hole on the mounting prism. The meausrementof CM1 is telling that the curverture center is located 2.7mm upper side of the center of the mirror if the HR side arrow is up (and it is the case). If we move the arrow to the QPD path side (90deg CW viewed from the face side), this corresponds to ~1.1mrad CCW tilt in Yaw (viewed from the top of the prism). According to the matrix calculation (T1500060) this will induce ~1.5mm shift of the beam. This should be tried before gluing.

- 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.

- Tried to use the IR viewer with the new rechargable battery brought from the 40m. But the view still didn't work. The possibility is a) the viewer is broken b) the battery is empty.

- Tried to use the stainless clean regulartor for the UHP N2. The outlet has a short tube with a different diameter. The O.D. of the old tube is 6.3mm, while the new one is 9.5mm. If I insert the thinner tube in the new tube, it approximately fits. But I don't believe this is the way...

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.

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 small compromise of the perpend.

The attachment is the excerpt from T1500060.

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.

The attachment is the excerpt from T1500060 with some highlighting.

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

[Koji,Philip, Liyuan, Joe]

CM1:

We moved the curved mirrors to these positions:

inner = 0.807mm

outer = 0.983 mm

CM2:

inner = 0.92 mm

outer = 0.85 mm

To do this so that realignment was easier, we moved the screws in steps of 5um. We alternated which mirror we adjusted so that we could monitor with a wincam how well aligned the beam into the cavity was. We only moved the cavity mirrors a small amount so we could still see higher order mode flashes transmitted through the cavity (e.g.TM03 modes). We would then improve the input alignment, and then move the cavity mirrors some more. Once the mirrors were adjusted according to http://nodus.ligo.caltech.edu:8080/OMC_Lab/190422_195450/misalignment4.pdf the spot positions looked near the middle of the curved mirrors (using a beam card). We began beam walking but we ran  out of range of the bottom periscope screws in the yaw dof. We tried using the third screw to move the mirrror in both yaw and pitch, hopefully this will let move the mirror such that we can use the just the yaw screw. This screw also ran out of range, so we decided that the cavity needed a small adjustment.

The curved mirrors were moved slightly (>5um) and then we tried to get alignment. By using the fibre coupler translation stage, we move the beam side ways slightly, and then tried to get the periscope mirrors back to a position where the screws could move the mirrors. Once we had an ok alignment, we checked the beam. It looked like it was pretty close to the centre of the curved mirrors, which is where we wanted it to be.

We then tried locking the cavity, although the error signal was quite small. The adjusted the input offset and gain of the servo (there is apparently some problem to do with the input and output offsets). Once the cavity was locked we could make the final adjustments to aligning. We still ran out of range on the periscope. We decided to move the breadboard with the fibre coupler and mode matching lenses on it. Because we knew that the cavity was aligned such that the beam hits the centres of the curved mirrors, we could regain flashes quite quickly. We saw the error signal go down, but eventually this decrease was just to do with the beam clipping on the periscope mirrors. We moved the spot back to where we ok aligned, and slid the periscope so we were not clipping the mirror. This worked very well, and then optimised the alignment.

We then tried to improve the mode matching. 

We took photos of the spot positions (quite near the center) and made the detuned locking measurement. The fitting of the data (attachment 1) wsa 1.1318m (what error should we put here?).

I think the order we did things in was:

• turning anti clockwise on the fibre coupler and misalign the diode, we measured the modespacing.
• returned the alignment for the photodiode, and realign fibre couple.
• miss align the photodiode horizontally, and then used fibre coupler to maximise the peak higher order mode peak height. We then used the PD again to make the peak height bigger.
•  

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, 30mA of photocurrent with the transimpedance of 400 Ohm is already enough to saturate the circuit. This means that the test is intended to check the damage of the photodiode mainly by the optical power.

The test procedure is as follows:

1. Illuminate the diode with certain optical power.
2. Measure the dark current and dark noise of the PD with no light on it.
3. Check the condition of the PD surface with a digital camera.
4. Repeat 1~3 with larger optical power.

The beam from an NPRO laser is delivered to the photodiode. The maximum power available is 300~400mW. The beam shape was regulated to have the beam radius of ~500um.

- When the PD is exposed to the high power beam, the circuit setup A) is used. This setup is intended to mimic the bias and transimpedance configuration used in the DCPD amp at the site.

- When the dark noise is measured, the circuit setup B) is used. This setup is low noise enough to measure the dark noise (and current) of the PD.

- The test procedure is going to be tested with an Excelitas 3mm InGaAs PD (C30665), and then tested with the high QE PD.

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.

Aim: To find the combinations of mounting prism+PZT+curved mirror to build two PZT sub-assemblies that best minimises the total vertical beam deviation.

(In short, attachment 1 shows the two chosen sets of components and the configuration according which they must be bonded to minimize the total vertical angular deviation.)

The specfic components and configuration were chosen as follows, closely following Section 2.3.3 of T1500060:

Available components:

Mounting prisms: 1,2,12,14,15 (Even though there is mention of M17 in the attachments, it can not be used because it was chipped earlier.)

PZTs: 12,13

Curved mirrors: 10,13

Method:

For a given choice of prism, PZT and mirror, the PZT can be placed either at 0deg or 180deg, and the mirror can rotated. This allows us to choose an optimal mirror rotation and PZT orientation which minimises the vertical deviation.

Total vertical angle 

 was measured by Koji as described in elog 369.

,              are the wedge angle and orientation respectively and were measured earlier and shown in elog 373 . 

,               The measurement of the location of the curvature bottom (d, ) of the mirrors is shown in elog 372 . The optimal  is to be found.

These steps were followed:

1. For every combination of prism, PZT, and mirror, the total vertical deviation was minimized with respect to the angle of rotation of the curved mirror computationally (SciPy.optimize.minimize). The results of this computation can be found in Attachment 2: where Tables 1.1 and 2.1 show the minimum achievable deviations for mirrors C10 and C13 respectively, and Tables 1.2 and 2.2 show the corresponding angle of rotation of the mirrors  .
2. From the combinations that show low total deviations (highlighted in red in Attachment 2), the tolerances for 5 arcsec and 10 arcsec deviations with mirror rotation were calculated, and is shown in Tables 1.3, 1.4, 2.3, 2.4 of Attachment 2.
3. While calculating the tolerances, the dependence of the vertical deviations with rotation were also plotted (refer Attachment 3).
4. Two sets from available components with low total deviation and high tolerance were chosen. 

Result:

These are the ones that were chosen:

1. M14 + PZT13 at 0deg + C13 rotated by 169deg anticlockwise (tot vertical dev ~ -3 arcsec)
2. M12 + PZT12 at 0deg + C10 rotated by 88deg clockwise (tot vertical dev ~0 arcsec)

The method of attaching them is depicted in Attachment 1.

The Windows laptop for WincamD/Beam'R2 (DELL Vostro3300) was not functional.
- Windows 7 got stuck in the starting up process (Google "startup repair loop")
- The battery can't charge and the adapter connection is flaky

I decided to newly install Win10.
I made a new bootable Win10 DVD from the ISO downloaded from IMSS. The ISO file was converted to CDR using Disk Utility on Mac.
This deleted the past disk partitions. The installation process has no trouble and Win10 ran successfully. The machine is slow but still acceptable for our purpose.
Dataray Version 7.1H25Bk was downloaded from the vendor website https://dataray.com/blogs/software/downloads and installed successfully.
The devices ran as expected by connecting the heads and selecting the proper device in the software.

Then, the Win10 fell into "Hibernation Loop" and "Shutdown loop" (after disabling hibernation in the safe mode).
This is probably the combination of extremely slow windows update (feature update i.e. beta OS update) and the occasional shutdown due to the flakiness of the AC connection

Win10 was reinstalled and automatic Win update was disabled via windows policy manager or something like that. Still, it tries to download and update some of the updates (what's happening there!?

Here are my strong recommendations on how to use this laptop

• Do not use any network connection. It will enable Windows Update kicks in and destroy the machine.
• Use a USB stick for data transportation if necessary
• The laptop should always be connected to the power supply at a stable location. (The adapter connection is flaky and the battery is dead)
• Buy a replacement battery (maybe a 3rd-party cheap one
• The Win10 DVD should always be inserted into the laptop's drive so that we can reinstall the windows anytime.

[Camille, Koji]

Began setting up fiber assembly for OMC testing:
-Aligned fiber mount to maximize transmission through fiber
-Adjusted polarization at output of fiber to minimize s-polarized output.

Power measurements:
fiber input: 56.7 mW
fiber output:43.2 mW
s-polarized output: 700 uW

Fiber matching: 43.2/56.7 = 76%
S/P-pol ratio 0.7/43.2 = 1.6%

Aaron took the set to Cryo lab

[Camille, Koji]

1. Flipping the OMC

It turned out that the transport fixture for this OMC could not be closed. The locks are too short, and the knobs could not be turned. We temporarily fastened the long 1/4-20 screws to secure the box and flipped it to make the top side face up.

2. Setting up the top-side template

The top side template was attached to the breadboard. We took care that the lock nuts on the positioning screws were not touched. The margins between the template and the glass edges were checked with a caliper. The long sides seemed very much parallel and symmetric, while the short sides were not symmetric. The lock nut on the short side was loosened, and the template was shifted to be symmetric w.r.t. the breadboard.

3. UV epoxy work

The cylindrical glass pieces were wiped, and the bonding surfaces were cleaned so that the visible fringes were <5 fringes. We confirmed the hooking side is properly facing up. The UV epoxy and UV curing were applied without any trouble. (Attachment 1)

4. EP30-2 bonding of the invar mounting blocks

Six invar blocks were bonded. This time the Allen key weights were properly arranged, so they didn't raise the blocks. The bond properly wetted the mating surfaces.

---

The final step of the bonding is to remove the template.
And replace the locks of the transport fixture.

Work log for June 14, 2023

• Selected QPDs from the stock: QPD#62 for QPD1 and QPD#70 for QPD2 were selected from the QPD stock T1200063.
• The legs of the QPDs were trimmed so that the cable could completely flush with the mount.
• A test PD (Excelitas) was mounted on a DCPD housing.
• They are ready for installation and testing.

QPD#              QPD1       QPD2
Housing#          #008       #009
Diode#            #62        #70
Shim              2.50mm 05  0.75mm 08   (see D1201467)
-------------------------------------
Power Incident     76.5 uW   71.5 uW
Sum Out            49.0 mV   50.2 mV
Vertical Out      -16.0 mV    8.2 mV
Horizontal Out    - 2.4 mV   -3.6 mV
SEG1              - 8.2 mV  -16.2 mV
SEG2              - 8.0 mV  -13.0 mV
SEG3              -15.1 mV  - 9.5 mV
SEG4              -17.4 mV  -11.5 mV
-------------------------------------
Spot position X   + 8   um  +33   um  (positive = more power on SEG1 and SEG4)
Spot position Y   +81   um  -52   um  (positive = more power on SEG3 and SEG4)
-------------------------------------
Responsivity[A/W] 0.64      0.70
Q.E.              0.75      0.82
-------------------------------------

Arrangement of the segments
View from the beam
/ 2 | 1 X
|---+---|
\ 3 | 4 /

---------------

I(w,x,y) = Exp[-2 (x^2 + y^2)/w^2]/(Pi w^2/2)

(SEG_A+SEG_B-SEG_C-SEG_D)/(SEG_A+SEG_B+SEG_C+SEG_D) = Erf[sqrt(2) d/w]

d: distance of the spot from the center
w: beam width

While using mirror SN14 and mirror SN30 for CM1 and CM2 respectively, we monitored the two beam spots on FM2 and continued to see ~5mm of vertical displacement between the two spots. We swapped the subassembly containing SN30 for the one containing SN02 and we see that the pitch misalignment is resolved. We will proceed to lock the cavity using the following mirrors:
FM1 --> SN11
FM2 --> SN17
CM1 --> SN14
CM2 --> SN02

LIGO Document G1200683-v1:
aLIGO OMC fabrication and testing plan

aLIGO OMC wiki

Facility

• Work
  • Replacing wooden work benches
    • W60" x H28-34" x D30" http://www.globalindustrial.com/p/work-benches/systems/adjustable-height/60x30-esd-square-edge-power-apron-production-bench-blue
    • W72" x H28-34" x D30" http://www.globalindustrial.com/p/work-benches/systems/adjustable-height/72x30-esd-square-edge-power-apron-production-bench-blue
    • Lower shelf W60" http://www.globalindustrial.com/p/work-benches/systems/adjustable-height/60-w-lower-shelf-bench-15-d-blue 
    • Lower shelf W72" http://www.globalindustrial.com/p/work-benches/systems/adjustable-height/72-w-lower-shelf-bench-15-d-blue
  • Replacing a cabinet at the south wall by a lockable cabinet
    • W36" x H72" x D20"
  • Cleaning of the floor
  • Plug a big hole on the wall (Done)
  • Plug slits on the roof of the HEPA booth - "There should be the blanking panels there."
     
  • Install laser Safety curtain (Peter is working on this)
     
  • Place a sticky mat
  • Prepare clean supplies (Shoes/Coverall/Hats/Gloves) => go to VWR stock room
  • Prepare Al foils (All foils inc, should get a certificate everytime to ensure UHV compatibility)
  • Plastic boxes for storage http://www.drillspot.com/products/422140/Rubbermaid_2282-00-CLR_18GAL_Clear_Snap_Case
    (Steve is helping Koji to get them)
     
• Design
  • Optical layout
     
• Test
  • Confirm particle level
     
• Note: Optical Table W96" x D48" x H27"

Mechanics

• Work 
  •  
• Design
  • How do we hold the PDs, QPDs, and black glass - we put 2 PDs and 2 QPDs on the PD mounting blacket.
  •  
•  
• Test
   
• Things to be tested
  • New suspension scheme (cup & cone design)
  • Balancing the plates
  • Dummy metal payload?
• => Suspending test with a suspension cage for a Faraday isolator@CIT
  • Supporting block for the suspension cage (to mimic the OMC suspension)
• Things to be designed
  • Wire end (cone)
  • Diode holding structures
    PD/QPD/PZT holding structure
• PZT alignment
• Prototyping with metal parts?
• UV glue? (heat) / gluing test
• Balance / ballast
   
• Solid works

Optics

• Mirrors to be delivered ~Aug
• Design down select
  • Between "Single output & BS" vs "Two outputs & no BS"
• Mode design
• Finalization of scattering paths / PD angles etc
   
• Things to be decided / confirmed:
  • How to handle optics / assemblies (Talk to the prev people)
  • First contact? (Margot: applicable to a short Rc of ~2.5m)
  • Gluing templates to be designed (how to handle it?)
• Things to be tested:
  • R&T of each mirror
  • Cavity ref/trans/finesse
  • PD QE / incident angle
     
• What PD do we use?
   
• CCD beam analyzer (Zach: It is fixed.)
   
• PD angle measurement
• Obtain EG&G 3mm PDs

Electronics

• Electronics / CDS electronics / software
   
• Things to be tested
  • QPD/PD pre-selections (QE/noise)
  • Functionality test of QPD/PD/PZT

Shipping, storage etc

• Shipping cage drawing
  https://dcc.ligo.org/cgi-bin/private/DocDB/ShowDocument?docid=70209

Jun/July
    - Lab renovtion
    - Mechanics design
    - Glue training
Aug
    - Mirror delivery
    - Basic optics test
Sept
    - Cavity test
    - Suspending test
NOV~DEC
    - Shipping to LLO

Open questions
    Two optical designs
    Procedure
    Modeling
    Clamp design / stencil design
    gluing-installation procedure

Facility/Supplies

• Work in progress
  
  • Floor cleaning
  • Plug slits on the roof of the HEPA booth - blanking panels have been ordered (Peter)
  • Install laser safety barrier (Peter is working on this)
  • Place a sticky mat
     
• Work to be done
  • Replacing a file cabinet next to the south wall by a lockable cabinet
  • Replacing a lab desk at the west side of the room. (Vladimir's)
  • Replacing Vladimir's rack with nicer one.
  • Laser sign
  • Safety glass holder
  • Prepare clean supplies (Shoes/Coverall/Hats/Gloves) => go to VWR stock room
    
    • glove 8.5,9,9.5
       
  • Label maker (P-Touch) & Tape
     　
• Design
  • Optical layout - Laser SOP
  • Additional HEPA stage
     
• Test
  • Confirm particle level
     
• Note: Optical Table W96" x D48" x H27"

Beaurocracy

• Laser SOP
• HV use?
• UV?

Mechanics

• Ongoing Work 
  • Cone-shaped wire clamp design (at the OMC end) - Jeff
     
• Design
  • Wire preparation fixture - Jeff
  • How do we hold the PDs, QPDs, and black glass - we put 2 PDs and 2 QPDs on the PD mounting blacket. - Jeff
  • Integrated solidwork model - Sam
    • Q: How the wires are clamped at the top side?
    • Q: How much the length of the wire should be?
    • Q: Locations of the wire mounts on the plate
  • Cabling investigation:
    • Where do the cables from the feed-thrus anchored? - Sam
    • List of the current internal cables and their lengths - Sam
    • List of the required internal cables and their lengths
    • Can we route the intermediate stage of the suspension? Do we need new cables?
  • Dummy intermediate stage structure
     
  • Metal templates
    • First, decide an optical design
    • takes at least a month
       
  • Weights how heavy / how many
     
• Test
  • Cone-shaped wire clamp test - Jeff/Koji 
  • Balancing the plates
    • The Faraday isolator cage isn't clean
  • Dummy metal payload test at the sites???
     
• Procedures to be decided
  • PZT alignment
  • Prototyping with metal parts?
  • UV glue? (heat) / gluing test
  • Balance

Optics

• Ongoing Work 
  
  • Mirrors to be delivered ~Aug
     
  • Design down select - Between "Single output & BS" vs "Two outputs & no BS"
  • Down selecting procedure:
    
    1. Assume ELIGO beam component
    2. Assume amount of 9MHz / 45MHz sidebands at the OMC input
    3. Calculate transmitted power
    4. Require HOM to be smaller than the TEM00 offset 
        
  • UV cured epoxy (Quate obtained)
    
    • Electronic Materials Inc.'s Optocast 3553LV-UTF-HM
      (A Low Viscosity, Ultra Thin Film epoxy with Heat Mechanism. The assembly/cure procedure includes both a UV binding step and a 120 degree cure for 24 hours.)
    • Ref1: Dennis Coyne, LIGO-E960050-v11,
      https://dcc.ligo.org/cgi-bin/private/DocDB/ShowDocument?docid=3879
    • Ref2: Tobin Fricke, LIGO Document P1000010-v1, Homodyne detection for laser-interferometric gravitational wave detectors
      https://dcc.ligo.org/cgi-bin/private/DocDB/ShowDocument?docid=8443
    • Ref3: OMC Construction Wiki https://awiki.ligo-wa.caltech.edu/aLIGO/OMC_Construction
    • The glue should be stored at T<0degC ==> Freezer in a lab
       
• Design
  
  • Mode design for HAM6 layout
  • Finalization of scattering paths
     
• Tests
  • Measurement of PD angles
  • R&T of each mirror
  • Curvature of the curved mirrors
  • Cavity ref/trans/finesse
  • PD Q.E. & Reflectivity measurement vs incident angle
     
• Things to be decided / confirmed
  • How to handle optics / assemblies (Talk to the prev people)
  • First contact? (Margot: applicable to a short Rc of ~2.5m)
  • Gluing templates to be designed (how to handle it?)
     
• PDs
  • Primary choice for DC PD: Exelitas C30665GH 3mm
    0.76A/W => Q.E. 0.88
    http://www.excelitas.com/downloads/dts_pe_pd_14_ingaasandsipindiodes.pdf
     
  • Primary choice for DC QPD: OSI FCI-InGaAs-Q3000
     
• Misc
  • CCD beam analyzer (Zach: It is fixed.)
  • Are two PZTs used?
    • YES, for redundancy, range, upconversion tests.
       
• Things to buy
  • Obtain EG&G 3mm PDs
  • Black Glass / Black Glass holder
  • Acetone.
  • N2 cylinder: 4N - UHP or 5N - Research Grade.
  • Paper lens tissue
  • Lint free cloth
  • The ionized gun used in the clean room at Downs: made by Terra Universal.com
    http://www.terrauniversal.com/static-control/ionizing-blow-off-guns.php
  • Flow path: N2 cylinder - Filter - Gun
  • Freezer

• Need to buy a fiber for mode cleaning?
  
• Mode content of the ELIGO dark beam?
• Jitter noise?
• How to determine the design?
• Why Fused Silica? (How much is the temp fluctuation in the chamber?)
• How to align the cavity mirrors, input mirrors, QPDs, PDs, beam dumps.
   

Electronics

• Thorough scrutinization of cabling / wiring / electronics
• Electronics / CDS electronics / software
• Things to be tested
  • QPD/PD pre-selections (QE/noise)
  • Functionality test of QPD/PD/PZT

Shipping, storage etc

• Shipping cage drawing
  https://dcc.ligo.org/cgi-bin/private/DocDB/ShowDocument?docid=70209

Jun/July
    - Lab renovtion
    - Mechanics design
    - Glue training
Aug
    - Mirror delivery
    - Basic optics test
Sept
    - Cavity test
    - Suspending test
NOV~DEC
    - Shipping to LLO

Open questions
    Two optical designs
    Procedure
    Modeling
    Clamp design / stencil design
    gluing-installation procedure

July:Facility/Supplies

• Completed Work: Facility/Supplies
  • Plug a big hole on the wall
  • Purchasing work benches
    
    • W60" x H28-34" x D30" http://www.globalindustrial.com/p/work-benches/systems/adjustable-height/60x30-esd-square-edge-power-apron-production-bench-blue
    • Lower shelf W60" http://www.globalindustrial.com/p/work-benches/systems/adjustable-height/60-w-lower-shelf-bench-15-d-blue
  • Wooden work benches removed(arranging the work with Louisa)
     
  • Al foils (All foils inc, should get a certificate everytime to ensure UHV compatibility)
  • Laser / UV safety glass/face mask (Ordered with Gina, UV face shield ordered through Techmart)
    • 35-200 Laser Glasses (PN 100-35-200) Qty.2 Price 189.00 ea
      http://www.lasersafetyindustries.com/35_200_Laser_Safety_Glasses_p/35-200.htm
    • Black Sport-wrap Laser Glasses 950-3600 nm (PN 100-38-200) Qty.1 Price 169.00 ea
      http://www.lasersafetyindustries.com/Black_Sport_wrap_Glasses_Diode_Nd_YAG_Er_YAG_p/100-38-200.htm
    • VWR has FACE SHIELD UVC-803 and this is ANSI-Z87.1 1986 compliant and the O.D. is more than 5.
      https://us.vwr.com/store/catalog/product.jsp?catalog_number=33007-151
  • Sticky mat
    
    • VWR MAT ADHESIVE 30L 18X36 BLU, 21924-110
  • Shoe cover
    • VWR SHOECVR NSKID AP XL 150PR, 414004-650
    • VWR SHOECVR NSKID AP 2XL 150PR, 414004-651
  • Lab coat
    
    • VWR Lab coat L 82007-618 / XL 82007-620
  • Hat
    
    • VWR Hat 10843-053
  • Mask
    
    • VWR Face Masks 10869-020
  • Gloves
    
    • VWR GLOVE ACCTCH NR-LTX SZ7.5 PK25 79999-306 x4
    • VWR GLOVE ACCTCH NR-LTX SZ8 PK25 79999-308 x4
  • Plastic boxes for storage
    http://www.drillspot.com/products/422140/Rubbermaid_2282-00-CLR_18GAL_Clear_Snap_Case
    (We have 12 for now. More stored at the 40m)
     
• Completed Work: Optics
  • UV Lamp arrived (shipped from LLO)
    
  • Fiber light guide for UV lamp (Quote obtained / Ordered via techmart) 

I consulted with Margot about the cleaning of the optics

• Optics are considered as a clean object. Large dusts can be removed by ionized N2 flow etc.
• Barrel of optics can be wiped with Acetone.
• Optical surfaces are best to be cleaned by First Contact.
• A peek mesh should be embedded in the first contact so that the First Contact sheet can be easily removed.
• When peeling a F.C. sheet from a mirror surface, ionized N2 should be brown for discharging.
• If there are residuals visible on the mirror surface, it should be removed by Acetone. Don't use alchols.
• Use paper lens tissue for wiping as the lint free wipe can be eaten by Acetone.
• In fact, All of the procedure is described in a certain document.
• For a small amount, Margot can provide us a bottle of F.C. and some PEEK meshes.

Details of the Ionized N2 system

• This N2 should have higher purity than 4N (UHP - Ultra High Purity). This means we should use 4N - UHP or 5N - Research Grade.
• The ionized gun used in the clean room at Downs: made by Terra Universal.com
• Flow path: N2 cylinder - Filter - Gun

Nicolas Smith,
LIGO Document T0900383-v1
3mm Photodiode Characterization for Enhanced LIGO
https://dcc.ligo.org/cgi-bin/private/DocDB/ShowDocument?docid=4498

Tobin Fricke,
LIGO Document P1000010-v1
Homodyne detection for laser-interferometric gravitational wave detectors
https://dcc.ligo.org/cgi-bin/private/DocDB/ShowDocument?docid=8443

Nicolas Smith,
LIGO Document P1200052-v1
Techniques for Improving the Readout Sensitivity of Gravitational Wave Antennae
https://dcc.ligo.org/cgi-bin/private/DocDB/ShowDocument?docid=90498

• Completed Work: Facility/Supplies
  • Plug a big hole on the wall [ELOG]
  • Purchasing work benches
    
    • W60" x H28-34" x D30" http://www.globalindustrial.com/p/work-benches/systems/adjustable-height/60x30-esd-square-edge-power-apron-production-bench-blue
    • Lower shelf W60" http://www.globalindustrial.com/p/work-benches/systems/adjustable-height/60-w-lower-shelf-bench-15-d-blue
  • Wooden work benches removed(arranging the work with Louisa)
     
  • Al foils (All foils inc, should get a certificate everytime to ensure UHV compatibility)
  • Laser / UV safety glass/face mask (Ordered with Gina, UV face shield ordered through Techmart)
    • 35-200 Laser Glasses (PN 100-35-200) Qty.2 Price 189.00 ea
      http://www.lasersafetyindustries.com/35_200_Laser_Safety_Glasses_p/35-200.htm
    • Black Sport-wrap Laser Glasses 950-3600 nm (PN 100-38-200) Qty.1 Price 169.00 ea
      http://www.lasersafetyindustries.com/Black_Sport_wrap_Glasses_Diode_Nd_YAG_Er_YAG_p/100-38-200.htm
    • VWR has FACE SHIELD UVC-803 and this is ANSI-Z87.1 1986 compliant and the O.D. is more than 5.
      https://us.vwr.com/store/catalog/product.jsp?catalog_number=33007-151
  • Sticky mat
    
    • VWR MAT ADHESIVE 30L 18X36 BLU, 21924-110
  • Shoe cover
    • VWR SHOECVR NSKID AP XL 150PR, 414004-650
    • VWR SHOECVR NSKID AP 2XL 150PR, 414004-651
  • Lab coat
    
    • VWR Lab coat L 82007-618 / XL 82007-620
  • Hat
    
    • VWR Hat 10843-053
  • Mask
    
    • VWR Face Masks 10869-020
  • Gloves
    
    • VWR GLOVE ACCTCH NR-LTX SZ7.5 PK25 79999-306 x4
    • VWR GLOVE ACCTCH NR-LTX SZ8 PK25 79999-308 x4
  • Plastic boxes for storage
    http://www.drillspot.com/products/422140/Rubbermaid_2282-00-CLR_18GAL_Clear_Snap_Case
    (We have 12 for now. More stored at the 40m)
     
• Completed Work: Optics
  • UV Lamp arrived (shipped from LLO)
    
  • Fiber light guide for UV lamp (Quote obtained / Ordered via techmart)
  • Optical test planning by Zach [ELOG]
  • How to handle First Contact by Margot [ELOG]
  • Useful links / OMC scanning [ELOG]

Completed work of the previous months: [Jul] [Aug] [Sep] [Oct] [Nov] [Dec]

Facility/Supplies

• Work done
  • Floor cleaning [ELOG]
  • Placing sticky mats [ELOG]
  • Label Maker purchased
  • Ordered a lab desk at the west side of the room
    http://www.globalindustrial.com/p/work-benches/systems/adjustable-height/72-l-x-36-w-production-bench-esd-square-edge-blue-2
  • Ordered clean / ESD  stools (~25" height)
    http://www.globalindustrial.com/p/office/stools/vinyl/esd-safe-vinyl-clean-room-stool-with-nylon-base-with-drag-chain-blue
  • Asked Gina for the electronics rack
    www.racksolutions.com/server-racks-cabinets-enclosures.html
    36U Height / 20" depth + Caster kit
  • 5 shelves ordered from AlliedElectronics (Quest technology ES0319-0115, 19"x15" non-vented shelf)
    http://www.racksolutions.com/rack-shelves
  • Plug slits on the roof of the HEPA booth (Peter)
  • Laser safety barrier (Peter) [ELOG]
  • Workbenches and clean room stools [ELOG]
     
• Things ordered
  
  • Office Depot
    • [delivered] Office Depot(R) Brand Stretch Wrap Film, 20 x 1000 Roll, Clear / 445013
    • [delivered] Eveready(R) Gold AA Alkaline Batteries, Pack Of 24 / 158448
    • [delivered] Rubbermaid(R) Roller Sponge Mop / 921841
    • [delivered] Rubbermaid(R) Roller Sponge Mop Replacement / 921858
    • [delivered] Rubbermaid(R) Sanitizing Caddy, 10 Quarts, Yellow / 674125
    • [delivered] Glad(R) Tall Kitchen Trash Bags, 13 Gallon, White, Box Of 28 / 269268
  • Global Industrial Equipment
    
    • [delivered] Extended Surface Pleated Cartridge Filter Serva-Cell Mp4 Slmp295 12X24X2 Gl    WBB431699
  • Global Industrial Equipment
    
    • [delivered] Nexel Poly-Z-Brite Wire Shelving 30"W x 21"D x 63"H Nexel Poly-Z-Brite™ Wire Shelving Starter Unit WB189209
    • [delivered] Stem Casters Set of (4) 5" Polyurethane Wheel, 2 With Brakes 1200 lb. Capacity WB500592    
  • Rack Solutions
    • [delivered] Open Frame Server Racks
      1 x 20" Depth Kit (Ideal for Audio/Video or Networking Racks) P/N: 111-1779
      1 x 36U, Rack-111 Post Kit P/N: 111-1728
      1 x Caster Kit for Open Frame RACK-111 P/N: 111-1731
    • [delivered] 36U Side Panel Kit $199.99 P/N: 102-1775
  • Rack shelf
    • [delivered] 1 RMS 19 X 15 SINGLE SIDED NON-VENTED SHELF 70121637
  • Work bench, Stools
    • [not yet] 72"L X 30"W Production Bench - Phenolic Resin Square Edge-Blue Form attached WB237381LBL    
    • [not yet] 72"W Lower Shelf For Bench - 15"D- Blue Form attached WB606951    
    • [not yet] ESD-Safe Vinyl Clean Room Stool with Nylon Base with Drag Chain Blue Form attached WBB560852    
  • P Touch
    • [delivered] Brother PT-2030 Desktop Office Labeler Punch-out product 672828    
    • [delivered] Brother(R) TZe-241 Black-On-White Tape, 0.75 x 26.2 Punch-out product 239384    
    • [delivered] Brother(R) TZe-231 Black-On-White Tape, 0.5 x 26.2 Punch-out product 239400    
      
  • UV light guide
    • [delivered] Fiber Optic Single Light Guide 5mm OD X 3mm ID X 1M L Note: This light guide can be used with MKIII UV Cure unit. OLB1081
  • Gloves (7.5, 8.0)
    • [delivered] GLOVE ACCTCH NR-LTX SZ7.5 PK25 Punch-out product 79999-306
    • [delivered] GLOVE ACCTCH NR-LTX SZ8 PK25 Punch-out product 79999-308
  • Lab coat (L,XL), Sticky Mat, Shoe Covers (L, XL), Cap, Mask
    • [delivered] LAB XP WH EL WR.COLL. NP L30EA Punch-out product 82007-618
    • [delivered] LAB XPWH EL WR.COLL. NP XL30EA Punch-out product 82007-620    
    • [delivered] VWR MAT ADHESIVE 30L 18X36 BLU Punch-out product 21924-110 (This was too small)
    • [delivered] VWR SHOECVR NSKID AP 2XL 150PR Punch-out product 414004-651    
    • [delivered] VWR SHOECVR NSKID AP XL 150PR Punch-out product 414004-650    
    • [delivered] CAP BOUFFANT 24IN RAYON CS500 Punch-out product 10843-053    
    • [delivered] MASK VLTC TIES N/STRL PK50 Punch-out product 10869-020
      
  • VWR
    • [delivered] FACE SHIELD UVC-803 Supplier: UVP 33007-151
       
  • [Delivered] Laser safety glasses
    
    • 35-200 Laser Glasses (PN 100-35-200) Qty.2 Price 189.00 ea
      http://www.lasersafetyindustries.com/35_200_Laser_Safety_Glasses_p/35-200.htm
    • Black Sport-wrap Laser Glasses 950-3600 nm (PN 100-38-200) Qty.1 Price 169.00 ea
      http://www.lasersafetyindustries.com/Black_Sport_wrap_Glasses_Diode_Nd_YAG_Er_YAG_p/100-38-200.htm

• Work in progress
  
  • 
     
• Work to be done
  • Replacing a file cabinet next to the south wall by a lockable cabinet
  • Laser sign
  • Safety glass holder/rack/shelf
  • Prepare clean supplies ~ glove 8.5,9,9.5
  • Ion gun safety issues: https://dcc.ligo.org/cgi-bin/private/DocDB/ShowDocument?docid=88631
     　
• Design
  • Optical layout - Laser SOP
  • Additional HEPA stage
     
• Test
  • Confirm particle level
     
• Note: Optical Table W96" x D48" x H27"

Beaurocracy

• Laser SOP
• HV use?
• UV?

Mechanics

• Ongoing Work 
  • Cone-shaped wire clamp design (at the OMC end) - Jeff
     
• Design
  • Wire preparation fixture - Jeff
  • How do we hold the PDs, QPDs, and black glass - we put 2 PDs and 2 QPDs on the PD mounting blacket. - Jeff
  • Integrated solidwork model - Derek
    • Q: How the wires are clamped at the top side?
    • Q: How much the length of the wire should be?
    • Q: Locations of the wire mounts on the plate
  • Cabling investigation:
    • Where do the cables from the feed-thrus anchored?
    • List of the current internal cables and their lengths
    • List of the required internal cables and their lengths
    • Can we route the intermediate stage of the suspension? Do we need new cables?
  • Dummy intermediate stage structure
     
  • Metal templates
    • First, decide an optical design
    • takes at least a month
       
  • Weights how heavy / how many
     
  • Earthquake stop design (Sam B)
     
• Test
  • Cone-shaped wire clamp test - Jeff/Koji 
  • Balancing the plates
    • The Faraday isolator cage isn't clean
  • Dummy metal payload test at the sites???
     
• Procedures to be decided
  • PZT alignment
  • Prototyping with metal parts?
  • UV glue? (heat) / gluing test
  • Balance

Optics

• Things ordered
  
  • Newport LB servo
  • Halogen Lamp
  • N2 cylinder/lines/filter
• Ongoing Work 
  
  • Mirrors to be delivered ~Aug
     
  • Design down select - Between "Single output & BS" vs "Two outputs & no BS"
  • Down selecting procedure:
    
    1. Assume ELIGO beam component
    2. Assume amount of 9MHz / 45MHz sidebands at the OMC input
    3. Calculate transmitted power
    4. Require HOM to be smaller than the TEM00 offset 
        
  • UV cured epoxy (Quate obtained)
    
    • Electronic Materials Inc.'s Optocast 3553LV-UTF-HM
      (A Low Viscosity, Ultra Thin Film epoxy with Heat Mechanism. The assembly/cure procedure includes both a UV binding step and a 120 degree cure for 24 hours.)
    • Ref1: Dennis Coyne, LIGO-E960050-v11,
      https://dcc.ligo.org/cgi-bin/private/DocDB/ShowDocument?docid=3879
    • Ref2: Tobin Fricke, LIGO Document P1000010-v1, Homodyne detection for laser-interferometric gravitational wave detectors
      https://dcc.ligo.org/cgi-bin/private/DocDB/ShowDocument?docid=8443
    • Ref3: OMC Construction Wiki https://awiki.ligo-wa.caltech.edu/aLIGO/OMC_Construction
    • The glue should be stored at T<0degC ==> Freezer in a lab
       
• Design
  
  • Mode design for HAM6 layout
  • Finalization of scattering paths
     
• Tests
  • Measurement of PD angles
  • R&T of each mirror
  • Curvature of the curved mirrors
  • Cavity ref/trans/finesse
  • PD Q.E. & Reflectivity measurement vs incident angle
     
• Things to be decided / confirmed
  • How to handle optics / assemblies (Talk to the prev people)
  • First contact? (Margot: applicable to a short Rc of ~2.5m)
  • Gluing templates to be designed (how to handle it?)
     
• PDs
  • Primary choice for DC PD: Exelitas C30665GH 3mm
    Peter has plenty of them
    0.76A/W => Q.E. 0.88
    http://www.excelitas.com/downloads/dts_pe_pd_14_ingaasandsipindiodes.pdf
     
  • Primary choice for DC QPD: OSI FCI-InGaAs-Q3000
     
• Misc
  • CCD beam analyzer (Zach: It is fixed.)
  • Are two PZTs used?
    • YES, for redundancy, range, upconversion tests.
       
• Things to buy
  
  • Black Glass / Black Glass holder
  • Acetone.
  • N2 cylinder: 4N - UHP or 5N - Research Grade.
  • Paper lens tissue
  • Lint free cloth
  • The ionized gun used in the clean room at Downs: made by Terra Universal.com
    http://www.terrauniversal.com/static-control/ionizing-blow-off-guns.php
  • Flow path: N2 cylinder - Filter - Gun
  • Freezer
  • Clean tools, tray, storage

• Need to buy a fiber for mode cleaning?
  
• Mode content of the ELIGO dark beam?
• Jitter noise?
• How to determine the design?
• Why Fused Silica? (How much is the temp fluctuation in the chamber?)
• How to align the cavity mirrors, input mirrors, QPDs, PDs, beam dumps.
• PZTs @LLO
   

Electronics

• Thorough scrutinization of cabling / wiring / electronics
  • ELIGO OMC Wiring diagram D070536-A2
    • Occupies 2 DB25s -> They were anchored on the sus cage
    • Preamps for DCPDs will be fixed on the ISI table
      -> DB25 for the DCPDs will be anchored on the table
    • Use longer thin cables for the DCPDs in order to route them through the suspension stages
    • Turn the heater cable to the one for the other PZT
• Electronics / CDS electronics / software
• Things to be tested
  • QPD/PD pre-selections (QE/noise)
  • PD preamp design (Rich)
  • Functionality test of QPD/PD/PZT

Shipping, storage etc

• Shipping cage drawing
  https://dcc.ligo.org/cgi-bin/private/DocDB/ShowDocument?docid=70209

Jun/July
    - Lab renovation
Aug
    - Mechanics design
    - Mirror delivery
Sept
    - Basic optics test
    - Glue training
Oct
    - Cavity test
Nov
    - Suspending test
Dec
    - Shipping to LLO

Open questions
    Two optical designs
    Procedure
    Modeling
    Clamp design / stencil design
    gluing-installation procedure

- The floor of the room was cleaned and waxed!

- Sticky mats are placed! Now we require shoe covers!

- Work benches are being built. One unit is done.

- The other is half done because the table top has chippings.

It seemed that a laser safety barrier was installed today!?

Floor wiped with a wet wiper (Aug 13, 2012)
Floor wiped with a wet wiper (Aug 15, 2012)
Floor wiped with a wet wiper (Sep 25, 2012)
Air conditioning prefilter replaced (Sep 25, 2012)
Floor wiped with a wet wiper (Oct 01, 2012)
Floor wiped with a wet wiper (Nov 06, 2012) / ATF too
Floor wiped with a wet wiper (Jan 04, 2013)
Floor wiped with a wet wiper (Mar 23, 2013)
Floor wiped with a wet wiper (Apr 17, 2013)
Air conditioning prefilter replaced (Apr 17, 2013)
Floor wiped with a wet wiper (Jun 24, 2013)
Removing Vladimir's mess. Floor swept with a broom (Jun 26, 2013)
Completed removing Vladimir's mess. Floor swept with a wet wiper (Jun 27, 2013)
Air conditioning prefilter replaced (Sep 12, 2013)
Floor wiper head replaced. (Dec 10, 2013)
Floor wiped with a wet wiper (Dec 10, 2013)
Floor wiped with a wet wiper (Apr 1, 2014)

Air conditioning prefilter replaced (Dec 30, 2014)
Air conditioning prefilter replaced (some time in 2015...)

Floor wiped with a wet wiper (Dec 1, 2015)
Floor wiped with a wet wiper (Aug 23, 2016)
Air conditioning prefilter replaced (Aug 8, 2017) = 1 stock remains
Air conditioning prefilter replaced (Unkniwn) = no stock remains
Air conditioning prefilter replaced (Jul 25, 2022) = 5 stock remains
Floor wiped with a wet wiper (Mar 7, 2023)

Aug 13, 2012 / 0.5um 1000~2000/(0.1 cu ft) / 0.7um   400-600/(0.1 cu ft) by ATF particle counter (MET ONE 227A)

They are counts/(0.1 ft^3)! These numbers should be multiplied by 10 to know the particle "CLASS".

Clean supplies & some cleaning tools are located at the right side of the entrance.
The file cabinet there was moved to the left side of the door, but will be removed eventually.

Last Friday, new workbenches were installed. Vladimir got a new table and a cleanroom stool.

The other two workbenches were also nicely set.

Particle counts

Before the prefilter is installed: 0.5um 1191cnts, 0.7um 346cnts

2:20 prefilter installed
2:25 0.5um 650 / 0.7um 255
3:00 0.5um 578 / 0.7um 99
4:00 0.5um 480 / 0.7um 102
5:00 0.5um 426 / 0.7um 76

They are counts/(0.1 ft^3)! These numbers should be multiplied by 10 to know the particle "CLASS".

1. It turned out that the particle counter MET ONE 227A at ATF shows
(particle count)/(0.1 ft^3)

This means that the numbers I saw previously should be multiplied by 10.
So the nominal class of the room was 5000.

2. As our GT-321s have no diffuser, I borrowed a diffuser from 227A.
The diffuser actually increases the count. We need to buy them.
All the measurments below are performed with the diffuser and calibrated in Count/ft^3.

3. Measured the particle level without the HEPA running.

With diffuser: [cnt/ft^3]

Over Class 10000

4. The two HEPA fans are turned on at the speed "MED".

Basically no particles are detected in the HEPA booth.

With diffuser, inside of the HEPA booth:

The particle level in the room (outside of the HEPA booth) is also improved

With diffuser, outside of the HEPA booth GT-321 #1:
0.3 um 18612
0.5 um   1728

5. The two HEPA fans are turned on at the speed "LOW".

Particle levels are still zero inside.

With diffuser, inside of the HEPA booth, GT-321 #1:
0.3 um 0
0.5 um 0

The particle level in the room (outside of the HEPA booth) is also improved
but the cleaning power for 0.3um seems degraded.

With diffuser, outside of the HEPA booth, GT-321 #1:
0.3 um 34488
0.5 um   1386

Based on Zach's experiment design, I wrote up a bit more detailed optical layout for the mirror test.

Item: Newfocus Fast PD
Qty.: 1
Mirror: Newfocus Fast PD
Mount: Post
Post: Post Holder (Newfocus)
Fork: Short Fork

Item: Thorlabs RF PD
Qty.: 1
Mirror: Thorlabs RF PD
Mount: Post
Post: Post Holder (Newfocus)
Fork: Short Fork

Item: Newfocus Broadband
Qty.: 1
Mirror: Newfocus EOM
Mount: Newfocus
Post: Custom Mount? or Pedestal X"?
Fork: Short Fork

Item: Newfocus Resonant
Qty.: 1
Mirror: Newfocus EOM
Mount: Newfocus
Post: Custom Mount? or Pedestal X"?
Fork: Short Fork

Item: ND Filter
Qty.: 2
Mirror: -
Mount: Thorlabs FIlter Holder
Post: Pedestal X"
Fork: Short Fork

Item: New Port Lens Kit 1"
Qty.: 1

Item: Thorlabs ND Kit
Qty.: 1

Item: Plano Convex Lens
Qty.: f=100, 100, 150, 200
Mirror: New Port (AR)
Mount: Thorlabs
Post: Post Holder (Newfocus)
Fork: Short Fork

Item: Bi-Convex Lens
Qty.: 75
Mirror: New Port (AR)
Mount: Post
Post: Post Holder (Newfocus)
Fork: Short Fork

Item: Flipper Mirror
Qty.: 1
Mirror: CVI Y1-10XX-45P
Mount: New Focus Flipper
Post: Pedestal X"
Fork: Short Fork

Item: Steering Mirror
Qty.: 8
Mirror: CVI Y1-10XX-45P
Mount: Suprema 1inch
Post: Pedestal X"
Fork: Short Fork

Item: PBS
Qty.: 3
Mirror: PBS 1inch BK7
Mount: Newport BS Mount
Post: Pedestal X"
Fork: Short Fork

Item: Knife Edge Beam Dump
Qty.: 4
Mirror: Thorlabs Knife Edge
Mount: Post
Post: Post Holder (Newfocus)
Fork: Short Fork

Item: Half Wave Plate
Qty.: 4
Mirror: CVI QWPO-
Mount: CVI
Post: Pedestal X"
Fork: Short Fork

Item: Quater Wave Plate
Qty.: 3
Mirror: CVI QWPO-
Mount: CVI
Post: Pedestal X"
Fork: Short Fork

Item: OMC Curved Mirror
Qty.: 2
Mirror: -
Mount: Suprema 0.5inch + Adapter
Post: Pedestal X"
Fork: Short Fork

Item: Prism Holder
Qty.: 1
Mirror: OMC Prism
Mount: Newport Prism Mount
Post: Pedestal X"
Fork: Short Fork

Item: CCD
Qty.: 1
Mirror: Thorlabs?
Mount: Thorlabs?
Post: Post Holder (Newfocus)
Fork: Short Fork

EGE&G 2mm photodiode angle response measured by Sam T1100564-v1

• HWP set
  
  • Optics: CVI QWPO-1064-08-2-R10
  • Mount: New Focus #9401
  • Post: Pedestal 2.5inch
  • Returned: Oct 19, 2012 by KA
• QWP set
  
  • Optics: CVI QWPO-1064-05-4-R10
  • Mount: New Focus #9401
  • Post: Pedestal 2.5inch
  • Returned: Jan 17, 2013 by KA
• Faraday set
  
  • Optics: OFR IO-2-YAG-HP Returned: Mar 21, 2013 by KA
  • Mount: New Focus #9701 Returned: Apr 17, 2013 by KA
  • Post: Pedestal (1.5+0.25inch)x2
• Steering Mirror 1
  
  • Optics: CVI Y1-1037-45S
  • Mount: Newport Ultima U100-AC
  • Post: Pedestal 3inch
  • Returned: Jan 17, 2013 by KA
• Steering Mirror 2
  
  • Optics: CVI Y1-1037-45P
  • Mount: Newport Ultima U100-AC
  • Post: Pedestal 3inch
  • Returned: Jan 17, 2013 by KA
• Steering Mirror 3
  • Optics: New Focus 5104
  • Mount: Newport Ultima U100-AC
  • Post: Pedestal 3inch
  • Returned: Jan 17, 2013 by KA
• Prism Mount
  
  • Mount: Thorlabs KM100P+PM1 2014/7/17
  • Post: Pedestal 1.5+1+1/8inch
• 0.5" Mirror Mount
  
  • Mount: Newport U50-AReturned: Apr 17, 2013 by KA
  • Mount: Newport U50-A 2014/7/17
  • Post: Pedestal 1.5+2inch
• Black Glass Beam Dump
  • Optics: 1" sq. schott glass x3
  • Mount: Custom Hexagonal 1"
  • Post: Pedestal 3inch
• PBS Set
  
  • 05BC16PC.9 (PBS 1064 1000:1)
    
  • Mount: Custom Aluminum
  • Returned: Jan 17, 2013 by KA
• Lenses
  
  • KBX067.AR33 f=125mm
  • KPX106 f=200mm, KPX109 f=250mm unknown-coat
  • KPX088.AR33 f=75mm
  • KPX094.AR33 f=100mm
  • PLCX-C (BK7) 3863 (f=7.5m), 2060 (f=4.0m), 1545 (f=3.0m), 1030 (f=2.0m) non-coat
  • PLCX-UV (FS) 30.9 non-coat(!) f=60mm
  • Returned: Jan 17, 2013 by KA
• Pedestals
  
  • 1/4" x5, 1/8" x3, Returned: Jan 17, 2013 by KA
  • 0.5" x1, 1.5" x1

Another loan from the 40m on Oct 17th, 2012

• Minicircuits
  
  • Splitter ZFSC-2-5 x2
  • Filter SLP-1.9 x2 / BLP-1.9 x1/2 / SLP-5 x1
  • Returned: Jan 17, 2013 by KA
• Connectors / Adaptors
  
  • SMA TEE x1 / SMA 50Ohm x 1 / BNC T x 10, Returned: Jan 17, 2013 by KA
  • SMA TEE x1 / SMA 50Ohm x 1Returned: May 20, 2013 by KA
• Pomona Box x1, Returned: Jan 17, 2013 by KA
• Pomona Box x1
• Power supply for New Focus Fast PD made by Jamie R Returned: Apr 17, 2013 by KA
• BS-1064-50-1037-45S / Newport U100-A mount / 1"+2" Pedestal, Returned: Jan 17, 2013 by KA
• BS-1064-50-1025-45P / Newport U100-A mount / 3/4" post + Base, Returned: Jan 17, 2013 by KA
• BNC cable 21ft x2, Returned: Jan 17, 2013 by KA
• SMA Cable 6ft

Another loan from the 40m on Nov 21th, 2012

• Mounting Base Thorlabs BA-2 x 17
• Mounting Posts (phi=3/4", L=2.65", normal x15, and 1/4"-20 variant x2)

Yet another loan from the 40m on Jan 16th, 2013

• V-groove Mounting Bases Custom. Qty.2Returned: Feb 25, 2013 by KA

Loan from ATF

32.7MHz EOM+Tilt aligner
Thorlabs Broadband EOM+Tilt aligner
Forks x 5Returned: Feb 25, 2013 by KA
JWIN Camera x 2