40m QIL Cryo_Lab CTN SUS_Lab CAML OMC_Lab CRIME_Lab FEA ENG_Labs OptContFac Mariner WBEEShop
  OMC elog, Page 3 of 13  Not logged in ELOG logo
ID Date Author Typeup Category Subject
  80   Mon Mar 25 18:34:25 2013 KojiGeneralGeneralOMC building plan / procedure ~ Mar 25 Mon

25 March (Mon):

Inspect the test PZT assembly

  • => Give it to Bob. (done)

Glue topside components (done)

  • Clean up the table for the gluing work.
  • Prepare the transport fixture on the table.
  • Glass breadboard
    • Pick breadboard #1 (cf. [ELOG 27])
    • Wipe the entire glass breadboard with IPA
    • Place the breadboard in the fixture (check which is the upper side)
  • Gluing
    • Set the gluing template on the breadboard.
    • Place all of the glass components on the plate (just for confirmation)
    • Wipe (locally) both surfaces to be glued.
    • Apply glue on the component to be glued
    • Align the components in the template. Use the cantilever pusher if necessary.
    • Illuminate UV
    • Repeat the above process for all of the components.
  • Close the transport fixture and wrap with Al foil
  82   Tue Mar 26 22:33:07 2013 KojiGeneralGeneralLoan for the OMC building

Loan from PSL Lab

- 300mm mirror with Ultima mount and pedestal
- Isopropanol small glass bottleReturned on Apr 12 2013.
- Newport 422-1S single-axis stage
Returned on Apr 12 2013.

Loan from ATF Lab

- 50/50 Cube BS 05BC16NP.9 without mount
- 1.5" pedestal (1/4-20 thread), 1/4" shim (1/4-20 through-hole), 1/8" shim (1/4-20 through-hole): 2 eachReturned on Aug 22, 2013.
- PBS & PBS mount
- Newport 422-1S single-axis stageReturned on Apr 12 2013.
- 10 ft BNC cable x 2
- some more BNC (labeled as ATF)Returned on May 20 2013.
- Y1-1037-45P with ultima mount 3inch post
- 1x Newfocus 5104 mirrorReturned on Aug 22, 2013.
- 4x ForkReturned on Aug 22, 2013.

Loan from 40m

- 4 BNC Ts and 1 BNC Ys
- 4 BNC Ts and 1 BNC YsReturned on May 20 2013.
- 6 BNC cablesReturned on May 20 2013.

- SONY CCD / CCD Monitor / CCD power supply
- Optical fiber tester (for fiber alignment) Returned on Apr 9 2013.

  83   Wed Mar 27 20:54:45 2013 KojiGeneralGeneralOMC building plan / procedure ~ Mar 26 Mon

26 March (Tue):

- Curved mirror characterization (Koji, done)

- Input optics for the cavity locking (Zach)

Faraday, BB EOM, Resonant EOM, AOM, MZ

  84   Wed Mar 27 20:54:54 2013 KojiGeneralGeneralOMC building plan / procedure ~ Mar 27 Wed

27 March (Wed)

- AOM drift investigation (Lisa, Zach)

- Cavity input optics ~ Fiber coupling (Zach)

Action Items

  • Glue curved mirror sub-assys.
  • R&T measurement
  85   Wed Mar 27 20:55:10 2013 KojiGeneralGeneralOMC building plan / procedure ~ Mar 28 Thu

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
  • Better coupling to the fiber
  • Matching to the OMC cavity


29 March (Fri):

Start gluing bottom side: Set 4 cavity mirrors and 1 HR mirror
   and try to resonate beam.  Glue when OK.

Place BS and DCPD mounting brackets.  Glue when OK.
Friday: Place QPDs and rest of optics.  Glue when OK.

WB 1 April

  • Testing at CIT
    • Transmission / Coupling / Loss
    • FSR / TMS
    • Power dependence
    • PZT position dependence
    • Back scattering
    • Openloop TF
    • PZT TF
    • Noise measurement
  • Epoxy cure bake at CIT
  • Retest at CIT
    • ditto

WB 8 April or after

  • Packing
  • Shipping - Shipping box?
  • Optical Testing at LLO (2 days anticipated)
  108   Thu Apr 11 15:10:22 2013 KojiGeneralGeneralOMC Progress

[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
curved mirrors are 6mm in the model. He added 0.3mmx2 to the dimensions.

- Jeff located the template on the breadboard such that each side has
the same amount of hanging out.

- Micrometer values

  • The one closest to the input mirror (CM1) 0.07
  • The other one on CM1 0.24
  • The one closest to the output mirror (CM2) 0.17
  • The other one on CM2 0.30

0.17         0.07
0.30         0.24

- Now the template is ready to accept the OMC optics.


- Zach and Koji finished a series of measurements for the test OMC.

Modulation depth:

- We scanned the laser PZT and recorded the data.
CH1: Reflection DC
CH2: PDH Error
CH3: Transmission (Magnified)
CH4: Transmission

- We should be able to obtain the estimation of the modulation depth and the finesse from this measurement.

- Rough calculation of the modulation depth is 0.19


- Incident 16.3mW
- Transmission 15.1mW
- This gave us the raw transmission of 92.6%ish.
- The modulation depth of 0.19 corresponds to 1.8% of the incident power
- The carrier reflection is almost dominated by the mode mismatch. (Note: We did not have a good resolution for the refl beam)  =>3.2%

- In total:The incident useful carrier power was 15.4mW ==> Throughput 98%
- There is slight headroom to increase the transmission by cleaning the mirrors.


- As our AOM is not functioning now, phase modulation sidebands are injected with the BBEOM.
- In principle, we can't expect any signal at the transmission at around the FSR frequency.
- If we apply small locking offset, the split peaks appear at the FSR frequency. The frequency of the dip corresponds to the FSR.
- We probably can extract the finesse of the cavity from this measurement. Lisa is working on this.


- The same PM injection gives us the frequency of the HOMs.
- We found that our EOM can work until ~500MHz.
- We could characterize the cavity resonance structure more than a single FSR.

  116   Thu Apr 18 11:43:59 2013 KojiGeneralGeneralMounting Glass Bracket Failure

[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.

- We borrowed a setup for photoelastisity measurement from Garilynn. This is a set of polarizer configured to have cross polarization. If there is no photoerastisity
the image is colored in blue (somehow). When the polarization is rotated, the color is changed in red, yellow, or white.

- The cross polarizer was tested with a polycarbonate face shield for the UV protection. It seems doing its job.

- We took a set of photos to see any residual stress in a block. The entire inside of the channel is frosted glass so the technique didn't yield much.
In one orientation we did see stress near the ends but the orientation didn't allow us to see exactly where.

- We had 30 brackets and one OMC requires ten of them. This means that there was no spare and now we don't have enough.
  So we decided to spend more as test pieces.

- We tested three scenarios this afternoon. In all three cases both screws were snugged (estimate 0.5 in*lb) before torquing by a torque wrench with a dial meter.
  The divisions on the dial of the wrench are 1 in*lb. We were not so confident in the exact measurement but we felt good about the repeatability of the values.

  1. Duplicated the original mounting with the chamfers of the PEEK bar facing into the channel. Cracked as the torque wrench read 1 in*lb.
      Crack initiation at the first screw, starting along the longitudinal centerline.

  2. Turned the nut bar over so the flat side faced into the channel. Successfully torqued both screws to 1 in*lb and removed them.

  3. With a razor blade, made fairly large reliefs (countersinks) around the holes in the PEEK. Successfully torqued both screws first to 1 in*lb then 1.5 in*lb.
      The block did crack (again at the screw along the centerline) when the torque was ~1.9 in*lb.

It occurs to us that we need micro-compliance AND structural rigidity to distribute the load. The PEEK bars are small and particularly thin where the #4-40 helicoil holes are.
The load is probably concentrated way too much at the holes because it is too weak. Perhaps a good solution, among others, would be to use an aluminum nut plate
with a thin (.02") kapton or viton layer to give the micro-compliance. Additionally, a kapton layer could be used between the block and the aluminum shim,
though this one is probably to be avoided so as to ensure rigidity of the bolted assembly to the bench. Lastly, the nut bar should be shaped such that the area
around the holes and the end of the channel (pretty much the same area) are less stressed than the center portion. 

After the discussion with Peter and Dennis, we decided to reinforce the bonded glass piece with invar shims.
Each shim will be threaded such that we don't need to stress the glass piece any more. EP30-2 will be used as the glue.

  118   Thu Apr 18 11:59:02 2013 KojiGeneralGeneralDCPD path gluing

[Jeff, Koji]

DCPD path gluing

Usual preparation

- Locked the cavity.

- Aligned the input beam to the cavity

DCPD BS gluing

- Placed the DCPD BS on the breadboard

- Placed the dummy DCPD mount on the reflection side of the BS. Check the height and position of the spot.

- Placed the dummy DCPD mount on the transmission side of the BS. Check the height and position of the spot.

- The spot positions looked fine.

- Added a dub of UV glue on the BS. Placed it along the fixture.

- Checked the reflection spot again with the CCD. Kept monitored the spot position through out the gluing process
of the BS.

- Blasted the UV illumination

Reflection side beam dump gluing

- Replaced the alignment disk of the dummy DCPD with a photodiode with the cap removed.

- Put the dummy DCPD mount and the beam dump in place

- Checked the reflection spot from the diode on the beam dump. It looked fine.

- Applied 2~3 dubs of the glue on the beam dump. Slid in the dump to the fixture.

- Applied UV illumination. As the beam dump shadows the illumination 3 times of 10sec blasts were applied.

Transmission side beam dump gluing

- Put the dummy DCPD mount with the diode in place

- Put the beam dump in place. The template needed to be lifted up a bit to accomplish this action.
This should be fixed by the modification of the template.

- Checked the transmission spot on the diode and the spot reflected from the diode on the beam dump.

- Actually the spot was too much close to the vertex of the "V" on the beam dump. We determined that
this was mainly caused by the misalignment of the diode element, and can be compensated by the tilt of the diode mount.

- Removed the beam dump from the template once. Applied 2~3 dubs of the glue on the beam dump.
Slid in the dump to the fixture by lifting up the template again.

- Applied UV illumination. As the beam dump shadows the illumination 3 times of 10sec blasts were applied.

Mounting bracket gluing

- Glued the mounting brackets for the DCPD mounts based on the positions specified by the template.

Removing the templates

- Removed the connection bars between the two templates.

- Removed the template at the QPD side. The screws at all of the three sides were needed to be released in order to accomplish this action.
Once the screws are released, the template was slid on the breadboard so that the pads did not scratch the optical surface.
Keep one side of the template use as a pivot, lifted up another side until the pads clear the optic. Then lifted up the other side.

- Removed the other template. This time, the screws at the two DCPD sides are released. The template was slid and lifted in a same way.

Last beam dump gluing

- Once the QPD side template was removed, the last beam dump at the transmission side of the first steering mirror was glued.

- This has been done without any gluing fixture, we held the beam dump with clean Allen keys on the breadboard.

- The paths for the main and stray beams were confirmed by an IR sensor card, and blasted the UV.

Closing the transport fixture

- Removed the constraining pins for the breadboard.

- Made sure all of the constraining pins/screws are released for the other side of the transport fixture were released.

- Put the lid on.

- Fastened the constraining pins/screws of the transport fixture.

- Wrapped the fixture with sheets of the Al foil.

- Pack the fixture in anti-static bags.

  119   Fri May 3 21:09:08 2013 KojiGeneralGeneralOMC is back

L1 OMC is back on the table for the action next week.

  122   Wed May 8 15:36:50 2013 KojiGeneralGeneralLatest OMC schedule
(done) Mon  6th: Invar plate arrival / Spot position measurement
(done) Tue  7th: Invar plate cleaning / Spot position measurement / EP30-2 arrival / Invar plate gluing to the test mounting brackets
(done) Wed  8th: Invar plate cleaning done / Baking of the test pieces (with Bob's oven)
Thu  9th: ***After bake torque/force test***

***If the invar plate passes the test***
Thu  9th Light side invar plate gluing
Fri 10th Cable side invar plate gluing

Mon 13th The OMC given to Bob (Air bake & Vac bake)

Mon 20th The OMC received from Bob
         Apply First contact
         Diode mount adjustment / Electronic tests
Tue 21st Diode mount adjustment / Electronic tests / Optical tests
Wed 22nd Final cabling (***Chub***)
Thu 23rd Final cabling / Packing
Fri 24th Packing / Shipping

Mon 27th? Arrival to LLO / Koji fly to LLO
Tue 28th Test on the optical bench
Wed 29th Test on the optical bench
Thu 30th Suspension test? (***Jeff B***)

Tue  4th Suspension test done?
  126   Mon May 13 15:00:23 2013 KojiGeneralGeneralCurrent most reliable OMC schedule
Tue 14th The OMC given to Bob (Air bake & Vac bake)

Mon 20th The OMC received from Bob
         Apply First contact
         Diode mount adjustment / Electronic tests
Tue 21st Diode mount adjustment / Electronic tests / Optical tests
Wed 22nd Final cabling (***Chub***)
Thu 23rd Final cabling / Packing
Fri 24th Packing / Shipping

Mon 27th? Arrival to LLO / Koji fly to LLO
Tue 28th Test on the optical bench
Wed 29th Test on the optical bench
Thu 30th Suspension test? (***Jeff B***)

Tue  4th Suspension test done?
  128   Mon May 20 14:59:21 2013 KojiGeneralGeneralOMC is out from the oven

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

  129   Tue May 21 18:28:08 2013 KojiGeneralGeneralCurrent most reliable OMC schedule

- The wrong Mighty Mouse connectors for the PZT wires were prepared. The correct ones are in the vacuum oven till Tuesday morning.

- The thread holes for the cable pegs are 1/4-20 rather than 10-24.  This requires re-machining of the cable pegs & the C&B.

- We are waiting for the fast shipment of the from LHO


Thu 23rd Diode mount adjustment / Optical tests
Fri 24th Optical tests
Tue 28th Mighty mouse connector available / Diode mounting finalization
Wed 29th final check
Thu 30th shipment
Fri 31th

Mon  3rd ? Arrival to LLO / Koji fly to LLO
Tue  4th Suspension test done?
  136   Mon Jun 3 21:19:03 2013 KojiGeneralGeneralPlanning

Monday - Evening
[done] - DCPD alignment
[done] - DCPD test & through-put measurement
[done] - Power dependence test
[done] - Apply Protective First Contact Layer on the optic surfaces
[done] - Wiping the OMC

Tuesday - Morning
[done] - Bring the cable from the oven

Tuesday - Afternoon
[done] - Cabling of the OMC

Wednesday - Morning
[done] - Cable tying down
[done] - Screw tightening for the PDs
[done] - Wrapping / Packing
[done] - Weighting? (65lb for everything)

[done] - Shipping? (or Wednesday)

Items to be shipped together
v - OMC cables between the cable harness to the suspension
v - 1 PZT cable pin
v - DCPD preamp kit
v - toruqe driver & bits
v - kapton sheet/tube
v - Test PD cables
v - Spare diodes
v - QPD amp circuits (just in case)
v - 1GHz PD / Power supply banana-PD cable / 1GHz PD cables

[done] - Installation scheduling with Peter/Brian/(Mike?)
- Travel plan
[done] Koji goes LLO immediately (possible?) 6/6-6/22
  Jeff goes LLO next week?

[done] - Room cleaning

Optical testing plan

Day 0
- Freight and Koji moving

Day 1 Arrival (Thursday or Friday)
- Inspect the shock detector
- Unpacking
- Check the condition of the breadboard
- Place the transportation fixture on the table
- Removing the First Contact layers
- Locking
- Mode matching

Day 2
- Transmission measurement
- Power dependence test
- PD installation / (diode can opening, optional)
- (PD realign, optional)
- diode test

Day 3
- Power dependence test

OMC installation plan


OMCS installation plan



- OMC Hazard analysis (done)
- OMCS Hazard analysis (done)
- OMC instllation procedure
- OMCS instllation procedure
- Work permits

cf. previous documents: E080024, E1300201


- LIGO access card
controls@lloisc0-work:~$ 2.23-5mW T
2.23-5mW: command not found
controls@lloisc0-work:~$ 2.17 \pm 0.01 R
2.17: command not found
controls@lloisc0-work:~$ 67-68mV inlock
67-68mV: command not found
controls@lloisc0-work:~$ 973mV unlock
973mV: command not found
controls@lloisc0-work:~$ Pin 5.47+-0.014.4
No command 'Pin' found, did you mean:


  137   Wed Jun 5 01:06:35 2013 ZachGeneralCharacterizationL1 OMC as-built diagram



  138   Wed Jun 5 18:19:51 2013 KojiGeneralGeneralSome recent photos from the OMC final test at CIT

Applying First Contact for the optics cleaning

PD alignment / scattering photos


Cabling (final) 

  139   Wed Jun 5 18:51:31 2013 KojiGeneralGeneralL1 OMC shipped out

[Koji, Jeff]

The L1 OMC finally sent out from Caltech!

CAM00011.jpg   P6054027.JPG

  140   Fri Jun 7 16:04:44 2013 KojiGeneralGeneral[LLO] OMC arrived

[Koji Zach Suresh]

The OMC arrived at LLO without any destruction!

  • We found that one shock sensor on the box turned red, the other stayed white.
  • We brought the Perican case to the changing room and the wrapping was opened in the optics lab.
  • The OMC was discovered without any obvious damage. Successful shipment!
  • The inspection with a halogen light indicated some amount of particules on the breadboard.
    The both sides of the breadboard were wiped with the cleanroom cloth.
  • The First Contact layers on the optics were removed while the ionized nitrogen gas was brew.


  141   Mon Jun 10 10:04:37 2013 KojiGeneralGeneral[LLO] OMC Test

[Koji Zach]

We worked on the OMC test over the weekend.

- At the beginning, the measured OMC transmission was ~85% even after subtracting the junk light and sidebands from the calculation.

- A pretty visible (by eye) dust were on CM1. Also a small residue of First Contact was found on the same mirror.

- We applied FC only on CM1 to remove these.

- The measued transmission went up to the level of 96%.

- We swept the incident power from 0.3mW to 30mW in order to see the dependence of the transmission against the incident power.

- The variation of the transmission ~10% was observed (attached figure 1, Red). This was compared with the similar dependence measured at Caltech (Magenta)

- So, the reduction of the transmission was observed as in eLIGO, although the measurements at Caltech and LLO are not consistent.

- Can this be attributed to the dependence of the PD efficiency? We measured the incident power on the PDs together with the preamp DC output. (Figure.2)
  This gives us how the responsivity changes with the incident power.

- Nevertheless, the dependence remains. We'll make more accurate measurement today.

  142   Thu Jun 13 12:04:57 2013 KojiGeneralGeneral[LLO] OMC Optical Test - completed


  143   Thu Jun 13 12:12:20 2013 ZachGeneralGeneral[LLO] OMC and OMCS in LVEA


  144   Fri Jun 14 06:35:21 2013 JeffGeneralGeneral[LLO] L1 OMC status



Suspension cage and transportation box: 250.8lb
Suspension cage and transportation box: 150.2lb ==> 100.6lb ==> 45,630 g

Metal Breadboard: 7261 g

Glass Breadboard and transportation fixture: 16382 g
Transportation fixture only: 9432 g ==> 6950 g
Added mass (up to now): 300 g ==> 7250 g

Preamp arrangement


  146   Tue Jun 18 15:45:38 2013 KojiGeneralGeneral[LLO] OMC installation in HAM6

OMC installed in HAM6!


  147   Fri Jun 28 12:20:49 2013 KojiGeneralGeneralDmass's loan of Thorlabs HV amp


(KA: Returned upon H1OMC building)

  149   Fri Aug 9 10:09:56 2013 KojiGeneralGeneralPZT Assembly #3/#4

Yesterday, Jeff and I bonded the PZT assemblies (#3/#4).
The attached is the arrangement of the components

  150   Mon Aug 12 20:22:19 2013 KojiGeneralGeneralPZT Assembly #5/#6

PZT Assembly #5/#6 were glued on Fri Aug 9th

They are removed from the fixture on Mon Aug 12th.

All of the four PZT assemblies were moved to the OMC lab.

  153   Fri Aug 16 17:21:38 2013 KojiGeneralGeneral[OMC002] Build started

[Jeff Koji]

The breadboard (SN2) was loaded on the transportation fixture.

The laser side template was installed and the cavity mirrors were placed.

The laser beam will be resonated in the cavity next week.

  164   Fri Aug 30 12:25:29 2013 KojiGeneralGeneralH1 OMC Invar mount gluing

The Invar Mounting Blocks were glued on the breadboard.

Serial number #1/2/5/6/7/8 -> I1 OMC cable side

Serial number #9/10/11/12 -> H1 OMC cavity side

  165   Tue Sep 3 17:03:25 2013 KojiGeneralGeneralH1 OMC gluing completed

[Koji Jeff]

H1 OMC All Gluing completed

5 Glue H1 beam dumps (UV)

4 glass wire brackets glued on the H1 topside (UV) SN: #9/10/11/12

6 Invar blocks glued on the H1 topside (EP30) SN: #13/14/15/16/18/19

  166   Wed Sep 4 22:22:54 2013 KojiGeneralGeneralH1 OMC wrapped and moved to the bake lab.

[Koji, Jeff]

We moved the H1OMC to the bake lab.

Chub set up the vacuum bake oven (Oven F) and running without the actual OMC.

We use low temperature (55degC) for the baking.

The actual OMC will be baked from tomorrow afternooon.

  167   Sat Sep 7 17:20:56 2013 KojiGeneralGeneralOMC/PD lab optical table wrapping

[Koji Jeff]

In order to prepare for the splinkler installation on the HEPA enclosure, the table with the optics was wrapped with Ameristat sheets.

  168   Fri Sep 13 15:09:20 2013 KojiGeneralGeneralSprinkler installation: done

A sprinkler head was installed on the HEPA enclosure. The head is covered with a plastic cap.

  173   Tue Oct 22 17:17:59 2013 KojiGeneralGeneralH1OMC cabling

[Chub, Jeff, Koji]

We worked on the wiring and routing of the cables.

- The cables for the PZT was installed first.

- Pins for the mighty mouse connector were crimped on the PZT wires

- Checked the wiring diagram (D1300589) to find the pinouts.
  Pin1 of the mighty mouse is connected to PZT2+, Pin2 to PZT2-, PIn3 to PZT1+, and Pin4 to PZT1-

- Then QPD and PD cables are fixed on the cable harness.

- The QPD/PD cables are attached on the diode housings.

During this process one of the DCPD mounts moved. The fixing screws were not torqued enough.
This means that all of the FC layers need to be removed and the DCPD housing should be aligned again.

- We continued on the cabling. The cables were routed on the top (cable) side.

- Some of the cable pegs were tightened by PEEK cable ties.

- We found that Pin1 and Pin2 of the PZT cables were not intact anymore.

- We ask Chub to work on the PZT pins tomorrow. The PD alignment will be taken tonight or tomorrow.

  174   Wed Oct 23 02:45:07 2013 KojiGeneralGeneralPD realignment

DCPD2 got misaligned during the cable installation. The PD alignment procedure have been gone through again.

Cavity locking

- Removed the FC layers for the cavity related mirrors.

- Aligned and locked the cavity.

PD alignment

- Loosen DCPD2. Checked the reflection with a IR card. Checked the spot on the PD with an IR viewer.

- Finger-tight the screws. Check the reflection with the card again. Check the pot on the PD with a CCD.

- If the spot positions are not satisfactory repeat the process.

- If the spot positions are satisfactory, take pictures of the CCD image.

- Fixing screws for all of the PDs/QPDs were tighten by the torque driver with a torque od 1.75 inch lb.

PD QE measurements

- Measure the power incident on the PDs.

- Set up the transimpedance amp to check the photo current.

- PD1 (T side) 9.10+/-0.03 V 13.02 +/- 0.01W -> QE ~80%

- PD2 (R side) 8.70+/-0.01 V 12.53 +/- 0.01W -> QE ~80%

- These are not strange values considering the presence of the glass caps.

PZT polarity check

- The connections between the PZT electrodes and the pins were checked.

- The positive side is marked by a knot on the wire.

FC painting

- The new FC bottle was brought from Downs, thanks to Margot.


  175   Mon Nov 4 19:43:56 2013 KojiGeneralGeneralH1OMC Packed

H1OMC PZT connector was replaced with the correct one. This was the final step for H1OMC.

Jeff and I packed the OMC and put it in the perikan case. It will be shipped tomorrow.

The other tools are also packed in the other box. Here is the list of the items

- Spare PD/QPDs (2 cages)
- Test PD/QPD cables
- Torque driver / bits
- Low noise transimpedance amp
- Kapton sheets
- First Contact kit
- 1/4-20 Screws for the balance weights
- OMC-Structure cables
- Preamp adapter plate
- Screws for the cable mounts
- Clean tools
  (scissors, tweezers, forceps, Diagonal pliers, long nose prier)
- Spare Peek cable ties
  176   Thu Nov 21 00:05:35 2013 KojiGeneralGeneralH1OMC electronics arrangement

Checked the PZT arrangement: Mighty Mouse Pin1&2 -> PZT2 (DCPD side), Mighty Mouse Pin3&4 -> PZT1 (QPD side)

DCPD response:
Illuminate DCPD1 (T) -> DCPD B responded in MEDM
Illuminate DCPD2 (R) -> DCPD A responded in MEDM

QPD response:
Illuminate QPD1 -> QPD A responded in MEDM
Illuminate QPD2 -> QPD B responded in MEDM


DCPD1 (T) is marked as "A". This PD is SN"0288"

DCPD2 (R) is marked as "B". This PD is SN"0721"

Corresponding iLOG for the performance

  177   Tue Dec 10 16:41:51 2013 KojiGeneralGeneralTo Buy

Masks / Wipes => done

  178   Tue Feb 18 18:58:38 2014 KojiGeneralGeneralLHO H1 OMC installation photos

LHO OMC installation photos

  179   Fri Feb 28 19:50:11 2014 KojiGeneralGeneralMisalignment ABCD matrix for the aLIGO OMC

Relationship between mirror misalignment and cavity mode shift was calculated.
The technique described in T0900647 by Sam Waldman was used.

The angles and displacement of the mirrors and beams are defined in the attached figure.

x1 = 0.893134 α + 1.10676 β + 1.32252 γ + 1.24619 δ
𝛳1 = 0.75864 α - 0.75864 β - 0.271075 γ + 0.271075 δ

x2 = 1.10676 α + 0.893134 β + 1.24619 γ + 1.32252 δ
𝛳2 = 0.75864 α + 1.24136 β - 0.271075 γ + 0.271075 δ

x3 = 1.32252 α + 1.24619 β + 1.1691 γ + 1.39962 δ
𝛳3 = -0.271075 α + 0.271075 β + 0.818668 γ - 0.818668 δ

x4 = 1.24619 α + 1.32252 β + 1.39962 γ + 1.1691 δ
𝛳4 = -1.24136 α - 0.75864 β - 0.271075 γ + 0.271075 δ

Assuming the flat mirrors are fixed:
If I want to move the x3 mirror up by 1mm without moving x4, the solution is
γ = -0.00197 mrad
δ = +0.00236 mrad

This yields:
x1 = +0.33mm, x2=+0.66mm, x3 = +1mm, x4 = 0mm

  180   Mon Mar 3 02:46:21 2014 KojiGeneralCharacterizationSpot positions scanned

Spot positions on CM1 and CM2 scanned according to the recipes provided by the previous entry.

The best result obtained was:

Transmission from FM2: 32.7mW
Incident on BS1: 34.4mW

Reflection (Unlocked): 5.99V
Reflection (Locked): 104mV
Reflection (Dark): -7.5mV

to accomodate the spot on BS1 it had to be about a mm moved from the template.

This gives us:
- Portion of the TEM00 carrier: R = 1-(104+7.5)/(5990+7.5) = 0.981
- Raw transmission: 32.7/34.4 = 0.950
- TEM00 transmission 0.950/R = 0.969
- Excluding the transmission of BS1: 0.969/0.9926 = 0.976
  => loss per mirror ~40ppm


  190   Tue Jun 24 18:43:15 2014 KojiGeneralGeneralICS entries for the OMC baking/assembly

For baking:

  • Assembly Name aLIGO Output Mode Cleaner
    Assembly Number D1201439
  • Part Name: Breadboard transport fixture
    Part # / Drawing #: D1201515

D1201274-V1-00-S009: OMC DCPD Housing        (remove part)
D1201274-V1-00-S010: OMC DCPD Housing        (remove part)
D1201275-V1-00-0006: OMC DCPD FACE PLATE        (remove part)
D1201275-V1-00-0007: OMC DCPD FACE PLATE        (remove part)
D1201280-V1-00-0006: OMC QPD HOUSING        (remove part)
D1201280-V1-00-0007: OMC QPD HOUSING        (remove part)
D1201281-V1-00-0006: OMC QPD FACE PLATE        (remove part)
D1201281-V1-00-0007: OMC QPD FACE PLATE        (remove part)
D1300052-V1-00-0003: aLIGO OMC BRACKET, CABLE CONNECTOR        (remove part)
D1300057-v2-00-0021: aLIGO CABLE PEG        (remove part)
D1300057-v2-00-0022: aLIGO CABLE PEG        (remove part)
D1300057-v2-00-0023: aLIGO CABLE PEG        (remove part)
D1300057-v2-00-0024: aLIGO CABLE PEG        (remove part)
D1300057-v2-00-0025: aLIGO CABLE PEG        (remove part)
D1300057-v2-00-0026: aLIGO CABLE PEG        (remove part)
D1300057-v2-00-0027: aLIGO CABLE PEG        (remove part)
D1300057-v2-00-0028: aLIGO CABLE PEG        (remove part)
D1300057-v2-00-0029: aLIGO CABLE PEG        (remove part)
D1300057-v2-00-0030: aLIGO CABLE PEG        (remove part)
D1300060-V1-00-0005: aLIGO OMC BRACKET, MASS MOUNTING        (remove part)
D1300060-V1-00-0006: aLIGO OMC BRACKET, MASS MOUNTING        (remove part)

More entries to be added (Found in the LHO OMC entry) [DONE]
D1300371-V2-00-S1301806: ISC DCPD Cable for OMC-Breadboard Bracket to DCPD #1
D1300372-V2-00-S1301807: ISC DCPD Cable for OMC-Breadboard Bracket to DCPD #2
D1300373-V3-00-S1301810: ISC QPD Cable for OMC-Structure to Breadboard Bracket
D1300374-V2-00-S1301813: ISC QPD Cable for OMC-Breadboard Bracket to QPD #1

  191   Fri Jun 27 12:29:50 2014 KojiGeneralGeneralOMC baking

The OMC went into the oven at around 2PM on Thursday. It will be baked at 80degC for 48 hours.
The RGA result will be obtained on Monday.

Link to the ICS entry


  192   Fri Jun 27 18:51:33 2014 KojiGeneralGeneralSupply

PTOUCH TAPE (12mm white) x 2

9V batteries

  193   Wed Jul 2 16:41:43 2014 KojiGeneralGeneralOMC baking

OMC is back from the oven today.

To Do:

Optical tests

  • Cleaning
  • Power Budget
  • FSR measurement
  • TMS measurement
  • TMS measurement (with DC voltage on PZTs)
  • PZT DC response
  • PZT AC response
  • QPD alignment
  • DCPD alignment
  • First Contact

Backscattering test

Cabling / Wiring

  • Attaching cable/mass platforms
  • PZT cabling
  • DCPD cabling
  • QPD cabling

Vibration test

Packing / Shipping

  194   Wed Jul 2 18:58:42 2014 KojiGeneralGeneralBeam dump delamination

While the OMC breadboard was being inspected, it was found that two out of five black-glass beam dumps showed sign of delamination.
(attached photos).

The base of the each beam dump is a fused silica disk (25mm dia.). The black glass pieces are bonded to the disk. The bond is EP30-2
epoxy without glass beads for bond lining. The disk is bonded on the fused silica bread board with Optocast UV low-viscous epoxy.
The delamination is about 70% of the bonded area. They don't seem to fall off immediately. But the glass pieces are not completely secure.
(i.e. finger touch can change the newton ring fringes) So there might be some risk of falling off during transportation.

The engineering team and I are exploring the way to secure them in-situ, including the method to apply UV epoxy with capillary action.

  195   Thu Jul 3 17:45:18 2014 KojiGeneralGeneralBeam dump delamination

Here is the resolution.

I'll apply fillets of EP30-2 along the edges of the black glass (See figure).
In order to allow the air escape from the gap, the inside of the V will not be painted.
In any case, I don't have a good access to the interior of the V.

Dennis assured that the outgassing level will be ok even if the EP30-2 is cured at the room temp if the mixture is good.
But just in case, we should run an RGA scan (after 50degC for 24hour vac bake).
I prefer to do this RGA scan right after all of the test and cabling and right before the shipment.
Dennis is checking if we can even waive the RGA scan owing to the small volume of the glue.


  200   Mon Jul 7 01:36:03 2014 KojiGeneralGeneralTo Do

Optical tests

  • Cleaning
  • Power Budget
  • FSR measurement
  • TMS measurement
  • TMS measurement (with DC voltage on PZTs)
  • PZT DC response
  • PZT AC response
  • QPD alignment
  • DCPD alignment

Backscattering test

Cabling / Wiring

  • Attaching cable/mass platforms
  • PZT cabling
  • DCPD cabling
  • QPD cabling

Vibration test


First Contact

Packing / Shipping

  201   Tue Jul 8 04:08:06 2014 KojiGeneralGeneralExpoxy reapplication for beam dumps

Firstly, the excess epoxy was removed using a cleaned razor balde

Secondly, EP30-2 epoxy was applied at the exterior edges of the beam dump.
Interior of the V were glued at two points. This is to keep the gap away from being trapped

Here is the result of the gluing. Some epoxy was sucked into the gap by capillary action.
I believe, most of the rigidity is proivded by the bonds at the edges.

  204   Thu Jul 10 08:34:57 2014 KojiGeneralGeneralTo Do

Optical tests

  • Cleaning
  • Power Budget
  • FSR measurement
  • TMS measurement
  • TMS measurement (with DC voltage on PZTs)
  • PZT DC response
  • PZT AC response
  • QPD alignment
  • DCPD alignment

Backscattering test

Cabling / Wiring

  • Attaching cable/mass platforms
  • PZT cabling
  • DCPD cabling (to be done at LHO)
  • QPD cabling (to be done at LHO)

Vibration test


First Contact

Packing / Shipping

  212   Sun Jul 20 17:20:39 2014 KojiGeneralGeneralThe 3rd (LIO) OMC was shipped out to LHO

The 3rd (LIO) OMC was shipped out to LHO on Friday (Jul 18) Morning.


- All of the on-breadboard cables should be attached and tied down.

- Peel First Contact paint and pack the OMC for storage.


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