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  OMC elog, Page 1 of 9  Not logged in ELOG logo
ID Date Authorup Type Category Subject
  309   Thu Sep 27 20:19:15 2018 AaronOpticsGeneralMontecarlo simulation of the phase difference between P and S pols for a modeled HR mirror

I started some analytic calculations of how OMC mirror motion would add to the noise in the BHD. I want to make some prettier plots, and am adding the interferometer so I can also compute the noise due to backscatter into the IFO. However, since I've pushed the notebook I wanted to post an update. Here's the location in the repo.

I used Koji's soft limit of 0.02 degrees additional phase accumulation per reflection for p polarization.

  310   Thu Nov 1 19:57:32 2018 AaronOpticsGeneralMontecarlo simulation of the phase difference between P and S pols for a modeled HR mirror

I'm still not satisfied/done with the solution to this, but this has gone too long without an update and anyway probably someone else will have a direction to take it that prevents me spinning my wheels on solved or basic questions.

The story will have to wait to be on the elog, but I've put it in the jupyter notebook. Basically:

  • I considered the polarization-separated OMC in several configurations. I have plots of DARM referred noise (measured free-running and controlled noise for the current OMC, thermal theoretical noise curve, scattered light) for the case of such an OMC with one lambda/2 waveplate oriented at 45 degrees. This is the base case.
  • I also considered such an OMC with a lambda/2 both before and after the OMC, where their respective polarization axes can be arbitrary (I look at parameter space near the previous case's values).
    • I optimize the BHD angle to balance the homodyne (minimize the E_LO^2 term in the homodyne readout).
    • I then optimize the rotations of the lambda/2 polarization axes to minimize the noise
    • For the optimum that is closest to the base case, I also plotted DARM referred length noise.

 

It's clear to me that there is a way to optimize the OMC, but the normalization of my DARM referred noise is clearly wrong, because I'm finding that the input-referred noise is at least 4e-11 m/rt(Hz). This seems too large to believe. 

Indeed, I was finding the noise in the wrong way, in a pretty basic mistake. I’m glad I found it I guess. I’ll post some plots and update the git tomorrow. 

  362   Thu May 16 12:41:28 2019 ChubGeneralGeneralfire pillow found on optics table

That is an expanding fire pillow, also known as firebrick.  It is used to create a fire block where holes in fire-rated walls are made and prevents lab fires from spreading rapidly to adjacent labs.  I had to pull cable from B254 to our labs on either side during a rather narrow window of time.  Some of the cable holes are partially blocked, making it difficult to reach the cable to them. The cable is then just guided to the hole from a distance.  With no help, it's not possible to see this material getting shoved out of the hole.  I can assure you that I took great pains not to allow the CYMAC coax to fall into any equipment, or drag against any other cables.   

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

https://alog.ligo-la.caltech.edu/aLOG/index.php?callRep=7410

Weights:

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

preamp_arrangement.png 

  346   Thu Apr 18 20:47:54 2019 JoeOptics OMC initial alignment and locking

[Joe, Phillip, Koji, Stephen]

*draft post, please add anymore info if I missed something*

  • made initial alignment of the cavity. To do this we used the periscope mirrors to aim the incoming beam at the centre of the first mirror and second (1st curved mirror) mirror. Using the micrometers (initial positions was 0.20mm), we moved the first curved mirror so that it hit the third mirror. We then used a combination of the periscope and first curved mirror movements to start seeing 2 or 3 round trips. micrometer was set to roughly 0.11mm. We then only used  periscope mirrors to align the beam into the cavity.
  • We set up a wincam at the transmission of the cavity. This was a useful was of seeing what mode was being transmitted through the cavity. We walked the beam with the periscope mirrors until we saw flashes of the TM00 mode.
  • Once the cavity was transmitting TM00 modes, we started to lock it. Once it was locked we looked at the the spot positions of beam on the mirrors. Phillip looked with an IR viewer and could see that the spots were too high on both the curved mirrors
  • We set up a CCD to capture an image of this. Two post holders have been left in place for easy movement of the CCD.

General notes about working with this set up. The lens on the CCD can come off quite easily, as you just change how much its screwed on to change the focus. Care should be taken that you don't know the template with this as well, as the camera is quite close to the template (and near the edge of the bench!). Also be mindful of the PZT wires, as they can pull the mirrors out of position.

Attachment 1 shows the position of the spots on the mirrors A14 and PZT11. The spots are about 3mm ish from the centre of the curved mirror in the vertical and horizontal direction. 

Attachment 2 sketch of mirror positions.

Attachment 3 shows the postion of the spot on PZT13. The spot is less near the edge than on PZT11, but its still 2mm ish from the centre of the curved mirror in both directions.

To move the beam horizontally we can use the alignment matrix in appendix C of T1500060. However since we don't have control over the pitch of the mirrors, moving the spots down could require us to inspect the glass breadboard/prisms for dust. We suspect that PZT could be the culprit, as we could not see newtonian rings between its base and the glass breadboard. One way to test this idea is just to clean the bottom of the PZT with acetone, and see if that improves the spot position. If we don't have to do any work to realign it, then this was not the issue.

Koji pointed out that the spot in attachment 1 is very near the edge of the optic, so shifting the beam horizontally could also fix the vertical issue. 

Attachment 1: IMG_7676.JPG
IMG_7676.JPG
Attachment 2: IMG_7666.JPG
IMG_7666.JPG
Attachment 3: IMG_7670.JPG
IMG_7670.JPG
Attachment 4: IMG_7883.JPG
IMG_7883.JPG
Attachment 5: IMG_7882.JPG
IMG_7882.JPG
  348   Fri Apr 19 09:35:28 2019 JoeGeneral Adjusting cavity axis, re-alignment of OMC and locking

[koji,philip, joe, liyuan, steven]

*still need to add photos to post*

PZT 11 was removed and inspected for so dust/dirt on the bottom of the prism. We saw a spot. We tried to remove this with acetone, but it stayed there. (Attachment 2, see the little white spec near the edge of the bottom surface of the prism)

current micrometer positions:

  • CM1: one closest to centre 11, close to edge 35 marking
  • CM2: both at 20 marking

Swapped PZT for PZT 22, cleaned the bottom and put it into position of CM1. We saw a low number of newton rings, so this is good.

We got a rough initial alignment by walking the beam with the periscope and PZT 22  mirrors. Once we saw a faint amount of transmission, we set up the wincam at the output. The reflected light from the cavity could also be seen to be flashing as the laser frequency was being modulated. 

Once it was roughly aligned, using the persicope we walked the beam until we got good 00 flashes. We checked the positions of the spots on the mirror with the beam card. This looked a lot better in the verticle direction (very near the centre) on both curved mirrors. We locked the cavity and contiued to align it better. This was done with the periscope until the DC error signal was about 0.6V. We switched to the fibre coupler after this. 

Once we were satisfied that he cavity was near where it would be really well aligned, we took some images of the spot positions. Using these we can work out which way to move the curved mirrors. Koji worked this out and drew some diagrams, we should attach them to this post. [Diagram: See Attachment 1 of ELOG OMC 350]

We made the corrections to the cavity mirrors

  • CM1: one closest to centre 11, close to edge 35+16 marking
  • CM2: I can't remember exactly, Koji created a diagram which would help explain this step [Diagram: See Attachment 2 of ELOG OMC 350]

The scatter from CM1 looked very small, it was hard to see with a viewer or CCD. We had to turn up the laser power by a factor of 3 to begin to see it, indicating that this is a good mirror.

Once this was done, the spot positions looked uch nearer the centre of each mirror. They look pitched 1mm too high, which might be because of the bottom surfaces of the prisms having a piece of dust on them? For now though it was good enough to try take the detuned locking FSR measurement and RFAM measurement. 

To see the higher order mode spacing, we misaligned them incoming beam in pitch and yaw so that the TM10 and TM01 modes were excited. The cavity transmission beam was aligned onto the photodiode such that we could make a transfer function measurement (i.e. shift the beam along the photodiode so that only half of the beam was on it, this maximises the amount of photocurrent).

attachment 1 shows the fitting of the detuned locking method for measuring FSR and cavity length/

I saved this data on my laptop. When I next edit this post (hopefully I will before monday, although I might be too tired from being a tourist in california...) I want to upload plots of the higher order mode spacing.

 

 

Attachment 1: FSR_Scan_Fitfsrdata.pdf
FSR_Scan_Fitfsrdata.pdf
Attachment 2: IMG_7679_cropped.jpg
IMG_7679_cropped.jpg
  351   Mon Apr 22 09:54:21 2019 JoeGeneral Shortening cavity (A5,A14,PZT11,PZT22) to get closer to design FSR

[Koji,Joe,Philip,stephen]

in units 20um per div on the micrometer [n.b. we reailised that its 10um per div on the micrometer]

CM1 inner screw pos: 11.5

cm1 outer screw pos: 33.5

cm2 inner screw pos: 11

cm2 outer screw pos: 13

the cavity is currently 3mm too long, move each mirror closer by 0.75mm

CM1 inner screw pos: 11.5+37.5 = 49

cm1 outer screw pos: 33.5+37.5= 71

cm2 inner screw pos: 11+37.5 = 48.5

cm2 outer screw pos: 13+37.5 = 50.5

The screws on the micrometers were adjusted to these values.

cleaned cm1 (PZT 11). There was a mark near the edge which we were not able to remove with acetone. On the breadboard there were 3 spots which we could not remove with acetone. Once we wiped the mirror and breadboard we put the mirror back. 

FM2 (A5). The prism looked quite bad when inspected under the green torch, with lots of lines going breadthways. We thought about replacing this with A1, however this has had the most exposure to the environment according to koji. This has a bit of negative pitch, so would bring down the beam slightly. We decided to continue to use A5 as it had worked fairly well before. The breadboard was cleaned, we could see a few spots on it, they were cleaned using acetone.

FM1 (A14). Near the edge of the bottom surface of the prism we could see some shiny marks, which may have been first contact. We attempted to scrape them off we tweezers. The breadboard looked like it had a few marks on it. These were hard to remove with the acetone, it kept leaving residue marks. We used isopropanol to clean this now, which worked much better. The sharp edges of the breadboard can cause the lens tissue to tear a bit, so it took a few rounds of cleaning before it looked good to put a prism on. The mirror was put back onto the breadboard. 

The cavity was aligned, then we realised that 1 turn is 500um, so its still too long (1.75mm long). The FSR was 264.433Mhz, which is 

CM2 still showed quite a bit more scattering than CM1, so we want to move this beam.

CM1:

  • inner = 0.405mm
  • outer = 0.67mm

CM2

  • inner = 0.507mm
  • outer = 0.42mm

want to increase by 1.7/4 = 0.425, so

CM1:

  • inner = 0.405+ 0.425 mm = 0.83 mm
  • outer = 0.67+ 0.425mm = 1.095 mm

CM2

  • inner = 0.507 + 0.425mm = 0.932 mm
  • outer = 0.42 + 0.425mm = 0.845 mm

we tried to align the cavity, however the periscope screws ran out of range, so we changed the mircometers on CM2. We tried this for quite some time, but had problems with the beam reflected from the cavity clipping the steering mirror on the breadboard (to close to the outer edge of the mirror). This was fixed by changing the angle of the two curved mirrors. (We should include a diagram to explain this).

The cavity was locke, the FSR was measured using the detuned locking method, and we found that the FSR = 264.805 MHz, which corresponds to a cavity length of 1.1321m

we took some photos, the spot is quite far to the edge of the mirrors (3 to 4mm), but its near the centre vertically. photos are 

123-7699 = CM2

123-7697 = CM1

 

 

Attachment 1: CM1_IMG_7699.jpg
CM1_IMG_7699.jpg
Attachment 2: CM2_IMG_7697.jpg
CM2_IMG_7697.jpg
  353   Tue Apr 23 10:21:12 2019 JoeOpticsConfigurationMoving the spots to the centre of the curved mirrors

[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.
  •  
Attachment 1: FSR_detuned_locking.pdf
FSR_detuned_locking.pdf
Attachment 2: CM1_IMG_7702.JPG
CM1_IMG_7702.JPG
Attachment 3: CM2_IMG_7704.JPG
CM2_IMG_7704.JPG
  354   Wed Apr 24 13:58:51 2019 JoeOpticsCharacterizationOMC power budget and UV Epoxy Bonding of BS1

[koji,philip,joe,liyuan,stephen]

need to add spot positions.

Mirrors: PZT11,PZT22, A14, A5

Measurement postion Power P_normalise
P_in 15.66+-0.01mV 3.251+-0.001
V_ref,lock 64+-2mV 3.22+-0.001
V_ref,unlock 2.808+-0.001 V 3.253+-0.001
P_qpd 99.5+-0.5 uW 3.24+-0.002
P_cm1 79.0+-0.5 uW 3.22+-0.002
P_cm2 76.2+-0.03 uW 3.22+-0.01
P_trans 14.55+-0.05 mW 3.22+-0.01
Vref,dark -6.286 mV +-0.01mV  

Mode matching = 97.72%

15.66-> 15.30mW coupled.

~100uW for QPD

->15.2mW in cavity

Trans = 14.55mW -> 95.7% transmission

The flat mirrors were the ones with the most scattering, so we thought about how to improve it. We tried to move the first flat mirror by pushing it with our finger so that he beam would move along the optic. We tried this a couple of times, however the second time we moved it we lost our alignment and could not retrieve it. We looked at the mirror and we could see quite a lot of newtonian rings. We could see a small fibre on the glass bread board. We cleaned the optics base and the gbb, and we could get the alignment back. The beam was aligned to the cavity, the spots no longer hit the centre of the CM2. 

We measured the power budget again.

Measurement position Power P_normalise
V_ref,lock 47mV 3.24V
P_trans 14.45+-0.005mW 3.24 +-0.003 V
V_ref,unlock 2.68+-0.001 V 3.25+-.003
     

mode matching = 1-47/2680 = 0.9824, 98.2% mode matching

same p_normalise so

15.66-> 15.34mW coupled.

~15.24mW in cavity

transmission = 14.45, so 94.8% transmission.

Koji noticed that FM1 wasn't touching the template correctly, so he re-aligned the cavity.

Afternoon session - UV Bonding (E1300201-v1 procedure 6.4.4 "Gluing" using procedure in section 7.2 "UV Gluing")

Wiped down UV PPE, UV Illuminator, and UV Power Meter

Applied Optocast 3553-LV Epoxy to sample fused silica optics, to test quantity of glue needed and to become familiar with the process and tools. Philip and Joe each created a successful bond. Joe's had 3 visible spots in the bulk of the bond. Acetone was used to scrub some residue of epoxy from the surface near the OD, which was likely cured. Short duration exposure (seconds) to acetone at the perimeter of the bond did not yield any weakening of bond.

While test pieces were bonded, Koji was making some adjustments to the cavity alignment in preparation for gluing of the steering mirror BS1.

Koji noticed that the spring clamp was causing pitch in the BS1 mirror, so he recommended that we utilize the "restrain by allen key" technique to load the mirror during curing.

Once aligned, we tried taking the BS1 mirror out of the template and then putting it back. We did this twice and both times the cavity needed realigning (with the curved mirrors as well as the input steering periscope). Why is this? Since the mirror was touching the template it should not have become misaligned right? Maybe the template moves slightly? I think before glueing in the cavity mirrors we should find out why probably? Koji took a look and claimed that a few optics may have been unconstrained. 

Planning between Koji and Joe led to placement of 5 drops of epoxy on the BS1 surface, to match the bonding area. At this point we noticed that the template was not secured very well, by poking down on it we could see it move. This might explain why we are becoming misaligned very easily. Once the prism was back on the board, Koji used allen keys to move around the prism. This was done until we could align it again (i.t looked too pitched). The beam was aligned back into the cavity, and the UV light was used to cure the bond. The reflected DC when locked was

  • pre-cured = 47mV
  • cured = 55 mV

so it looks ok still.

 

 

 

  355   Thu Apr 25 15:05:19 2019 JoeOpticsCharacterizationLooking at PZT HOM spacing dependance and thinking about workflow

[koji, joe]

The template or glass breadboard was wobbling, and we noticed that the caivty alignment became worse/better when it was pressed down. We saw that it was the glass breadboard, so it was fixed into the transport fixture more securely. Now its alignement didn't change when it was pressed down. We took a pzt mirror out and replaced it, the alignment din't change much so that was good. We set up posts to hold the pzt wires.

We noticed that the bottom of the mirrors were dirty, so we cleaned them, and once we were happy with the newton rings, we aligned the cavity

Took a photo of CM2, the spot is maybe 1 beam diameter vertically and horizontally from the centre, and quite a bright spot could be seen. The same problem with CM1. We thought it would be good to see a measurement of higher order mode spacing dependence on PZT DC voltage rather than doing the full characterisation since the alignment seems to change quite a lot when ever we do anything, and this cavity arrangement probably isn't very good anyway (can see scattering on both curved mirrors with the IR camera). 

did measurements of FSR, = 2.64835MHz

did HOM spacing for 0,75,150V on CM1 in pitch and yaw.

we want to come up with a work flow for how to do these measurements, and make automate parts of the analysis?

 

  1   Fri Jun 15 15:45:49 2012 KojiGeneralGeneralOMC Plan

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

aLIGO OMC wiki

  2   Sat Jun 16 08:53:09 2012 KojiGeneralGeneralTo Do List

Facility

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


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

  3   Wed Jun 20 00:10:53 2012 KojiFacilityGeneralHole on the wall was patched

P6191706.jpg

  7   Sat Jul 14 02:16:07 2012 KojiGeneralGeneralPlan Update: July

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)
  • 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
  • Misc
    • CCD beam analyzer (Zach: It is fixed.)
    • Are two PZTs used?
      • YES, for redundancy, range, upconversion tests.
         
  • Things to buy
  • 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


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

Attachment 1: P7071878.jpg
P7071878.jpg
  8   Wed Jul 18 23:20:13 2012 KojiOpticsCharacterizationMode scan results of ELIGO

Nic Smith sent me a bunch of elog lists where the results of the mode scan can be found.

From Nic:

There have been many mode scan analyses done at LLO:
http://ilog.ligo-la.caltech.edu/ilog/pub/ilog.cgi?group=detector&date_to_view=06/07/2008&anchor_to_scroll_to=2008:06:07:20:55:41-jrsmith
http://ilog.ligo-la.caltech.edu/ilog/pub/ilog.cgi?group=detector&date_to_view=06/16/2008&anchor_to_scroll_to=2008:06:16:17:47:11-waldman
http://ilog.ligo-la.caltech.edu/ilog/pub/ilog.cgi?group=detector&date_to_view=08/06/2009&anchor_to_scroll_to=2009:08:06:12:23:16-kissel
http://ilog.ligo-la.caltech.edu/ilog/pub/ilog.cgi?group=detector&date_to_view=09/25/2009&anchor_to_scroll_to=2009:09:25:20:57:47-kate

We didn't do as much of this at LHO. At some point we were trying to figure out how the arm cavity mode was different from the carrier mode:
http://ilog.ligo-wa.caltech.edu/ilog/pub/ilog.cgi?group=detector&date_to_view=04/17/2009&anchor_to_scroll_to=2009:04:17:23:15:05-kawabe
http://ilog.ligo-wa.caltech.edu/ilog/pub/ilog.cgi?group=detector&date_to_view=03/27/2009&anchor_to_scroll_to=2009:03:27:21:38:14-kawabe

http://ilog.ligo-wa.caltech.edu/ilog/pub/ilog.cgi?group=detector&date_to_view=02/18/2009&anchor_to_scroll_to=2009:02:18:20:15:00-kawabe

Here's a long mode scan that was done, and the data is attached to the elog, but none of the amplitudes are analyzed.
http://ilog.ligo-wa.caltech.edu/ilog/pub/ilog.cgi?group=detector&date_to_view=07/08/2009&anchor_to_scroll_to=2009:07:08:17:02:19-nicolas

  10   Mon Jul 23 17:15:14 2012 KojiCleanGeneralTalking with Margot

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
  11   Tue Jul 24 11:41:29 2012 KojiGeneralGeneralUseful references

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

  12   Tue Jul 31 21:29:43 2012 KojiGeneralGeneralWork completed in July [!]

 

  13   Tue Jul 31 21:33:17 2012 KojiGeneralGeneralPlan Update: August [!]

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


Facility/Supplies

  • Work done
  • 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
  • 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)
  • 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
  • Misc
    • CCD beam analyzer (Zach: It is fixed.)
    • Are two PZTs used?
      • YES, for redundancy, range, upconversion tests.
         
  • Things to buy
  • 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


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

  14   Wed Aug 1 19:35:00 2012 KojiFacilityGeneralFloor cleaned / Workbench being built / Table top defect

- The floor of the room was cleaned and waxed!

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

P8011949.JPG

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

P8011948.JPG

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

P8011947.JPG

  15   Sat Aug 11 00:59:14 2012 KojiFacilityGeneralLaser Safety Barrier

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

P8131960.JPG

 

  16   Mon Aug 13 16:59:11 2012 KojiCleanGeneralRoom Cleaning Log

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

  17   Mon Aug 13 17:01:35 2012 KojiCleanGeneralParticle Counts

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".

  18   Tue Aug 14 03:29:06 2012 KojiSupplyGeneralClean supply rack

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.

P8131959.JPG    P8131961.JPG

  19   Wed Aug 22 20:16:43 2012 KojiFacilityGeneralWorkbenches have been installed / Clean room stools

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

P8171968.jpg

The other two workbenches were also nicely set.

P8171969.jpg

  20   Tue Sep 25 14:18:14 2012 KojiCleanGeneralParticle Counts

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".

  21   Mon Oct 1 16:06:55 2012 KojiCleanGeneralParticle Counts

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]

  GT-321 #1 GT-321 #2   227A
0.3um 152622 137511 -
0.5um  14706 14823   11860

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:

  GT-321 #1 GT-321 #2  227A 
0.3um 0 0
-
0.5um 0 0 0

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

 

  22   Fri Oct 5 03:39:58 2012 KojiOpticsGeneralRoC Test setup

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

RoC_test_setup.png

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

Attachment 1: RoC_test_setup.pdf
RoC_test_setup.pdf
  23   Mon Oct 8 11:30:47 2012 KojiOpticsGeneralEG&G 2mm photodiode angle response

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

  24   Tue Oct 9 04:59:24 2012 KojiOpticsGeneralOMC Test Optical Setup

OMC_test_setup.png

 

Attachment 2: OMC_test_setup.pdf
OMC_test_setup.pdf
  25   Tue Oct 9 05:03:15 2012 KojiElectronicsGeneralOMC Test Electronics Setup

electronics_setup.png

Attachment 2: electronics_setup.pdf
electronics_setup.pdf
  26   Fri Oct 12 17:15:19 2012 KojiOpticsGeneralLoan from the 40m / ATF
  • 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

  28   Tue Oct 16 15:50:09 2012 KojiGeneralGeneralWork completed in August/September [!]
  • Work done
  • 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

 

  29   Tue Oct 16 15:51:01 2012 KojiGeneralGeneralPlan Update: October [!]

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


Facility/Supplies

  • Work in progress
    • RoC measurement
    • R&T measurement
    • Wedge measurement
  • Work to be done
    • Replacing a file cabinet next to the south wall by a lockable cabinet
    • Additional clean supplies ~ glove 8.5,9,9.5
    • Stainless bats
    • Ion gun safety issues: https://dcc.ligo.org/cgi-bin/private/DocDB/ShowDocument?docid=88631
        
  • Design
    • Laser SOP
       
  • Test
    • Continuous monitoring of the particle level
       
  • Note: Optical Table W96" x D48" x H27"

Beaurocracy

  • Laser SOP / HV use? / UV?
  • Procedures to be decided
    • PZT alignment
    • UV glue? (heat) / gluing test
    • Balance
    • N2 cylinder/lines/filter
  • Design
    • Mode design for HAM6 layout
    • Finalization of scattering paths
       
  • 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
  • Things to buy
  • 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

  30   Wed Oct 17 20:36:04 2012 KojiOpticsGeneralRoC test cavity locked

The RoC test setup has been built on the optical table at ATF.

The cavity formed by actual OMC mirrors have been locked.

The modulation frequency of the BB EOM was swept by the network analyzer.
A peak at ~30MHz was found in the transfer function when the input beam was misaligned and clipping was introduced at the transmission PD.
Without either the misalignment or the clipping, the peak disappears. Also the peak requires these imperfections to be directed in the same way
(like pitch and picth, or yaw and yaw). This strongly suggests that the peak is associated with the transverse mode.

The peak location was f_HOM = 29.79MHz. If we consider the length of the cavity is L=1.20m, the RoC is estimated as

RoC = L / (1 - Cos[f_HOM/(c/2/L) * PI]^2)

This formula gives us the RoC of 2.587 m.

I should have been able to find another peak at f_FSR-f_TMS. In deed, there was the structure found at 95MHz as expected.
However, the peak was really weak and the location was difficult to determine as it was coupled with the signal from residual RFAM.

The particle level in the clean booth was occasionally measured. Every measurement showed "zero".

To be improved:

  • The trans PD is 1801 which was found in ATF with the label of the 40m. It turned out that it is a Si PD.
    I need to find an InGaAs PD (1811, 1611, or my BBPD) or increase the modulation, or increase the detected light level.
    (==> The incident power on 1810 increased. Oct 17)
  • The BS at the transmission is actually Y1-45P with low incident angle. This can be replaced by 50% or 30% BS to increase the light on the fast PD.
    (==> 50% BS is placed. Oct 17)
  • I forgot to put a 50ohm terminator for the BB EOM.
    (==> 50Ohm installed. Oct 17)
  • A directional coupler could be used for the BBEOM signal to enhance the modulaiton by 3dB.
  • The mode matching is shitty. I can see quite strong TEM20 mode.
  • Use the longer cavity? L=1.8m is feasible on the table. This will move the peak at 27MHz and 56MHz (FSR=83MHz). Very promising.
    (==> L=1.8m, peak at 27MHz and 56MHz found. Oct.17)
Attachment 1: detailed_RoC_setup.pdf
detailed_RoC_setup.pdf detailed_RoC_setup.pdf
Attachment 2: omc_cav_lock_SCRN_SHOT.png
omc_cav_lock_SCRN_SHOT.png
Attachment 3: Cav_scan_response_20121016.pdf
Cav_scan_response_20121016.pdf
  31   Thu Oct 18 20:23:33 2012 KojiOpticsCharacterizationImproved measurement

Significant improvement has been achieved in the RoC measurement.

  • The trans PD has much more power as the BS at the cavity trans was replaced by a 50% BS. This covers the disadvantage of using the a Si PD.
  • The BB EOM has a 50Ohm terminator to ensure the 50Ohm termination at Low freq.
  • The length of the cavity was changed from 1.2m to 1.8m in order to see the effect on the RoC measurement.

By these changes, dramatic increase of the signal to noise ratio was seen.

Now both of the peaks corresponds to the 1st-order higher-order modes are clearly seen.
The peak at around 26MHz are produced by the beat between the carrier TEM00 and the upper-sideband TEM01 (or 10).
The other peak at around 57MHz are produced by the lower-sideband TEM01 (or 10).

 

Peak fitting

From the peak fitting we can extract the following numbers:

  • Cavity FSR (hence the cavity length)
  • Cavity g-factor
  • Approximate measure of the cavity bandwidth

Note that the cavity itself has not been touched during the measurement.
Only the laser frequency and the incident beam alignment were adjusted.

The results are calculated by the combination of MATLAB and Mathemaica. The fit results are listed in the PDF files.
In deed the fitting quality was not satisfactory if the single Lorentzian peak was assumed.

There for two peaks closely lining up with different height. This explained slight asymmetry of the side tails

This suggests that there is slight astigmatism on the mirrors (why not.)

The key points of the results:

- FSR and the cavity length: 83.28~83.31MHz / L=1.799~1.800 [m] (surprisingly good orecision of my optics placement!)

- Cavity g-factor: Considering the flatness of the flat mirror from the phase map, the measured g-factors were converted to the curvature of the curved mirror.
RoC = 2.583~4 [m] and 2.564~7 [m]. (Note: This fluctuation can not be explained by the statistical error.)
The mode split is an order of 10kHz. This number also agrees with the measurement taken yesterday.

If the curved mirror had the nominal curvature of 2.5m, the flat mirror should have the curvature of ~20m. This is very unlikely.

- Approximate cavity line width: FWHM = 70~80kHz. This corresponds to the finesse of ~500. The design value is ~780.
This means that the locking offset is not enough to explain the RoC discrepancy between the design and the measurement.

 

Attachment 1: Cav_scan_response_zoom_20121017.pdf
Cav_scan_response_zoom_20121017.pdf
Attachment 2: detailed_RoC_setup.pdf
detailed_RoC_setup.pdf
  32   Wed Nov 7 01:28:20 2012 KojiOpticsCharacterizationWedge angle test (A1)

Wedge angle test

Result: Wedge angle of Prism A1: 0.497 deg +/- 0.004 deg


 

Principle:

o Attach a rail on the optical table. This is the reference of the beam.

o A CCD camera (Wincam D) is used for reading out spot positions along the rail.

o Align a beam path along the rail using the CCD.

o Measure the residual slope of the beam path. (Measurement A)

o Insert an optic under the test. Direct the first surface retroreflectively. (This means the first surface should be the HR side.)

o Measure the slope of the transmitted beam. (Measurement B)

o Deflection angle is derived from the difference between these two measurements.

Setup:

wedge_measurement_setup.png

o An Al plate of 10" width was clamped on the table. Four other clamps are located along the rail to make the CCD positions reproducible.

o A prism (Coating A, SN: A1) is mounted on a prism mount. The first surface is aligned so that the reflected beam matches with the incident beam
with precision of +/-1mm at 1660mm away from the prism surface. ==> precision of +/- 0.6mrad

o In fact, the deflection angle of the transmission is not very sensitive to the alignment of the prism.
The effect of the misalignment on the measurement is negligible.

o Refractive index of Corning 7980 at 1064nm is 1.4496

Result:

Without Prism
Z (inch / mm), X (horiz [um] +/-4.7um), Y (vert [um] +/-4.7um)
0” / 0, -481.3, -165.1
1.375" / 34.925, -474.3, -162.8
3" / 76.2, -451.0, -186.0
4.375" / 111.125, -432.5, -181.4
6" / 152.4, -432.5, -181.4
7.375" / 187.325, -330.2, -204.6
9" / 228.6, -376.7, -209.3

With Prism / SN of the optic: A1
Z (inch / mm), X (horiz [um] +/-4.7um), Y (vert [um] +/-4.7um)
0” / 0, -658.3, -156.8
1.375" / 34.925, -744.0, -158.1
3" / 76.2, -930.0, -187.4
4.375" / 111.125, -962.6, -181.4
6" / 152.4, -1190.4, -218.6
7.375" / 187.325, -1250.9, -232.5
9" / 228.6, -1418.3, -232.5

Analysis:

Wedge angle of Prism A1: 0.497 deg +/- 0.004 deg

wedge_measurement.png[Click for a sharper image]

  33   Wed Nov 7 20:21:42 2012 KojiGeneralGeneralWork completed in October [!]

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


 

  34   Wed Nov 7 20:44:11 2012 KojiGeneralGeneralPlan Update: November [!]

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


  • Work done
    • Wedge measurement (1st trial) [ELOG]
    • RoC measurement [ELOG]
  • Work in progress
    • R&T measurement
    • Wedge measurement
  • Work to be done
    • QPD/PD pre-selections (QE/noise)
    •  
    •  
    •  
    • Misc. / Beaurocracy?
      • Continuous monitoring of the particle level
      • Replacing a file cabinet next to the south wall by a lockable cabinet
      • Ion gun safety issues: https://dcc.ligo.org/cgi-bin/private/DocDB/ShowDocument?docid=88631
      • Laser SOP / HV use? / UV?
  • Things delivered
  • Things ordered
    • Power strips Tripp Lite PS3612 (Ordered Nov. 8, Delivered Nov. 12)
    • Kapton tapes (1in x 6, 1/2in x 12 Delivered Nov. 15)
    • Sticky Mats (VWR 18888-216 Delivered Nov. 12 and 21992-042)
    • Duck tape (PK3) (Delivered Nov. 12)
    • Wipers 12"x12" 2ply x 119 pairs x case15 (Delivered Nov. 12)
    • Syringes (1mL&2mL) & Needles (20G x dozen)
    • Stainless trays with cover (Steve Delivered Nov. 12)
    • Gold Plated allen keys (Steve Delivered Nov. 12)
    • Forceps (Delivered Nov. 12) / Tweezers / Scissors (Delivered Nov. 12)
  • Things to buy / get
    • OMC testing optics / opto-mechanics
    • Black Glass / Black Glass holder / AR ==> Some at the 40m, some from LLO
    • Ionized air blow
      • N2 or Air cylinder: 4N - UHP or 5N - Research Grade.  (... steal from Downs)
    • Clean tools, tray, storage
    • Supply
      • Additional clean supplies ~ glove 8.5,9,9.5
      • Stainless bats / Pure solvents (Metha / Aceton / Iso) / Syringes / Lint free cloth / Paper lens tissue
      • Lab coats
    • ATF
      • Tefron tape
      • Thorlabs 8-32 screw kit / Thorlabs HW-KIT1
      • Pedestal Shims - Newport
  • Things to be done
    • Cavity ref/trans/finesse
    • PD Q.E. & Reflectivity measurement vs incident angle
    • Functionality test of QPD/PD (PeterK) /PZT
       
  • Procedures to be decided
    • PZT alignment
    • UV glue? (heat) / gluing test
    • Balance
    • N2 cylinder/lines/filter
    • Shipping procedure: New shipping cage design on going (Jeff) => Plastic box similar to COC
  • Design
    • Solidworks raytracing model
    • Mode design for HAM6 layout
       
  • 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?)
  • Jitter noise?
  • How to align the cavity mirrors, input mirrors, QPDs, PDs, beam dumps.

Electronics ==> Rich

Attachment 1: OMC_Project_Schedule.pdf
OMC_Project_Schedule.pdf
  35   Thu Nov 8 13:24:53 2012 KojiOpticsCharacterizationMore wedge measurement

A1
Horiz Wedge    0.497    +/-    0.004 deg
Vert Wedge      0.024    +/-    0.004 deg

A2
Horiz Wedge    0.549    +/-    0.004 deg
Vert Wedge      0.051    +/-    0.004 deg

A3
Horiz Wedge    0.463    +/-    0.004 deg
Vert Wedge      0.009    +/-    0.004 deg

A4
Horiz Wedge    0.471    +/-    0.004 deg
Vert Wedge      0.019    +/-    0.004 deg

A5
Horiz Wedge    0.458    +/-    0.004 deg
Vert Wedge      0.006    +/-    0.004 deg

Attachment 1: wedge_measurement_overall.pdf
wedge_measurement_overall.pdf wedge_measurement_overall.pdf wedge_measurement_overall.pdf wedge_measurement_overall.pdf wedge_measurement_overall.pdf
  36   Thu Nov 8 19:47:55 2012 KojiElectronicsConfigurationSolder for PZTs

Rich saids:

I have ordered a small roll of solder for the OMC piezos. 
The alloy is: Sn96.5 Ag3.0 Cu0.5

  37   Thu Nov 8 19:52:57 2012 KojiOpticsGeneralHow to apply UV epoxy

KA's question:

Do you know how to apply this epoxy?
Do we need a plunger and a needle for this purpose?

Nic saids:

When we did it with Sam, I seem to remember just squirting some on some foil then dabbing it on with the needle.

Attachment 1: UVepoxy.jpg
UVepoxy.jpg
  38   Thu Nov 8 20:12:10 2012 KojiOpticsConfigurationHow many glass components we need for a plate

Optical prisms 50pcs (A14+B12+C6+E18)
Curved Mirrors 25pcs (C13+D12)

  Qty

Prisms

Curved No BS OMC Wedge tested
Coating A: IO coupler   14 0  2 prisms 5/5
Coating B: BS 45deg   12 0  2 prisms  0/5
Coating C: HR   6 13 2 curved  
Coating D: Asym. output coupler   0 12 -  
Coating E: HR 45deg   18 0  4 prism (1 trans + 3 refl) 0/3
D1102209 Wire Mount Bracket 25      4  
D1102211 PD Mount Bracket 30      8  

 

  39   Fri Nov 9 00:43:32 2012 KojiOpticsCharacterizationFurther more wedge measurement

Now it's enough for the first OMC (or even second one too).
Today's measurements all distributed in theta>0.5deg. Is this some systematic effect???
I should check some of the compeled mirrors again to see the reproducibility...

A1    Horiz Wedge    0.497039    +/-    0.00420005    deg / Vert Wedge     0.02405210    +/-    0.00420061    deg

A2    Horiz Wedge    0.548849    +/-    0.00419993    deg / Vert Wedge     0.05087730    +/-    0.00420061    deg
A3    Horiz Wedge    0.463261    +/-    0.00420013    deg / Vert Wedge     0.00874441    +/-    0.00420061    deg
A4    Horiz Wedge    0.471536    +/-    0.00420011    deg / Vert Wedge     0.01900840    +/-    0.00420061    deg
A5    Horiz Wedge    0.458305    +/-    0.00420014    deg / Vert Wedge     0.00628961    +/-    0.00420062    deg

B1    Horiz Wedge    0.568260    +/-    0.00419988    deg / Vert Wedge    -0.00442885    +/-    0.00420062    deg
B2    Horiz Wedge    0.556195    +/-    0.00419991    deg / Vert Wedge    -0.00136749    +/-    0.00420062    deg
B3    Horiz Wedge    0.571045    +/-    0.00419987    deg / Vert Wedge     0.00897185    +/-    0.00420061    deg
B4    Horiz Wedge    0.563724    +/-    0.00419989    deg / Vert Wedge    -0.01139000    +/-    0.00420061    deg
B5    Horiz Wedge    0.574745    +/-    0.00419986    deg / Vert Wedge     0.01718030    +/-    0.00420061    deg
E1    Horiz Wedge    0.600147    +/-    0.00419980    deg / Vert Wedge     0.00317778    +/-    0.00420062    deg
E2    Horiz Wedge    0.582597    +/-    0.00419984    deg / Vert Wedge    -0.00537131    +/-    0.00420062    deg
E3    Horiz Wedge    0.592933    +/-    0.00419982    deg / Vert Wedge    -0.01082830    +/-    0.00420061    deg

-------

To check the systematic effect, A1 and B1 were tested with different alignment setup.

A1    Horiz Wedge    0.547056    +/-    0.00419994    deg / Vert Wedge    0.0517442    +/-    0.00420061    deg
A1    Horiz Wedge    0.546993    +/-    0.00419994    deg / Vert Wedge    0.0469938    +/-    0.00420061    deg
A1    Horiz Wedge    0.509079    +/-    0.00420003    deg / Vert Wedge    0.0240255    +/-    0.00420061    deg

B1    Horiz Wedge    0.547139    +/-    0.00419994    deg / Vert Wedge    0.0191204    +/-    0.00420061    deg



 

Attachment 1: wedge_measurement_overall.pdf
wedge_measurement_overall.pdf wedge_measurement_overall.pdf wedge_measurement_overall.pdf wedge_measurement_overall.pdf wedge_measurement_overall.pdf wedge_measurement_overall.pdf wedge_measurement_overall.pdf wedge_measurement_overall.pdf
Attachment 2: 121108a_A1.pdf
121108a_A1.pdf 121108a_A1.pdf 121108a_A1.pdf 121108a_A1.pdf
  40   Sat Nov 17 02:31:34 2012 KojiOpticsCharacterizationMirror T test

Mirror T test

The mirror was misaligned to have ~2deg incident (mistakenly...) angle.

C1: Ptrans = 7.58uW, Pinc = 135.0mW => 56.1ppm

C1 (take2): Ptrans = 7.30uW, Pinc = 134.4mW => 54.3ppm

C2: Ptrans = 6.91uW, Pinc = 137.3mW => 50.3ppm

C3: Ptrans = 6.27uW, Pinc = 139.7mW => 44.9ppm

C4: Ptrans = 7.62uW, Pinc = 139.3mW => 54.7ppm

C5: Ptrans = 6.20uW, Pinc = 137.5mW => 45.1ppm

A1: Ptrans = 1.094mW, Pinc = 133.6mW => 8189ppm

  41   Mon Nov 19 13:33:14 2012 KojiOpticsCharacterizationResuming testing mirror RoCs

In order to resume testing the curvatures of the mirrors, the same mirror as the previous one was tested.
The result looks consistent with the previous measurement.

It seems that there has been some locking offset. Actually, the split peaks in the TF@83MHz indicates
the existence of the offset. Next time, it should be adjusted at the beginning.

Curved mirror SN: C1
RoC: 2.5785 +/- 0.000042 [m]

Previous measurements
=> 2.5830, 2.5638 => sqrt(RoC1*RoC2) = 2.5734 m
=> 2.5844, 2.5666 => sqrt(RoC1*RoC2) = 2.5755 m

Attachment 1: Cav_scan_response_zoom_20121016.pdf
Cav_scan_response_zoom_20121016.pdf
  42   Mon Nov 26 01:40:00 2012 KojiOpticsCharacterizationMore RoC measurement

C1: RoC: 2.57845 +/− 4.2e−05m

C2: RoC: 2.54363 +/− 4.9e−05m

C3: RoC: 2.57130 +/− 6.3e−05m   

C4: RoC: 2.58176 +/− 6.8e−05m

C5: RoC 2.57369 +/− 9.1e−05m

 

==> 2.576 +/- 0.005 [m] (C2 excluded)

Attachment 1: RoC_measurement.pdf
RoC_measurement.pdf RoC_measurement.pdf RoC_measurement.pdf RoC_measurement.pdf RoC_measurement.pdf
  43   Thu Nov 29 21:18:23 2012 KojiOpticsGeneralOMC Mounting Prisms have come

PB293030.JPG

PB293032.JPG

  44   Tue Dec 18 20:04:40 2012 KojiOpticsCharacterizationPrism Thickness Measurement

The thicknesses of the prism mirrors (A1-A5) were measured with micrometer thickness gauge.
Since the thickness of the thinner side (side1) depends on the depth used for the measurement,
it is not accurate. Unit in mm.

A1: Side1: 9.916, Side2: 10.066 => derived wedge angle: 0.43deg
A2: Side1: 9.883, Side2: 10.065 => 0.52
A3: Side1: 9.932, Side2: 10.062 => 0.38
A4: Side1: 9.919, Side2: 10.060 => 0.40
A5: Side1: 9.917, Side2: 10.058 => 0.40

prism.png

  45   Wed Dec 19 18:47:03 2012 KojiCleanGeneralFirst Contact Training with Margot

Steve and I visited Margot to have a training session for application of First Contact on optics.

- Make "thick" layer of first contact. It becomes thin when it gets dried.

- Apply more FC once a peek sheet is placed on the FC

- Wait for drying (~15min)

- Rip off the FC layer by pulling a peek tab. Make sure the ionized N2 is applied during ripping.

- Margot has a Dark Field Microscope. We checked how the dusts are removed from the surface.
There are many dusts on the mirror even if they are invisible. First Contact actually removes
these dusts very efficiently. Margot told us that even carbonhydrates (like finger prints) can be removed by FC.

ELOG V3.1.3-