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⇤ ← Revision 1 as of 2025-03-31 15:42:51
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Size: 2148
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| Deletions are marked like this. | Additions are marked like this. |
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| * Mounting base can be [[Thorlabs BA1/M|https://www.thorlabs.com/thorproduct.cfm?partnumber=BA1/M]] with [[20 mm dia. posts|https://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=8429]] | * Mounting base can be [[https://www.thorlabs.com/thorproduct.cfm?partnumber=BA1/M|Thorlabs BA1/M]] with [[https://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=8429|20 mm dia. posts]] |
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| * Let's aim for 800 mm dia. optical breadboard size inside the PD chamber | |
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* Huali showed almost the final layout idea for AS RF and OMC REFL, with squeezing injection optics. * OSTM transmission seems different from CAD * Probably because OSTM wedge is not included in Huali's calculations * Add periscopes for AS RF in-vac path and OMC REFL path, and a beam diverter for AS RF in-vac path * Adding periscopes can reduce the height from approx. 210 mm to 4 inch, and we can use smaller and lighter pedestals * Check if OMC shroud is not conflicting * Next step is to collect comments for AS and to start REFL/POP planning * New student might be available * REFL/POP should be done by around summer |
* Updated the layout based on the comments from the last meeting (OSTM wedge, periscope and distance traveled within periscope, beam diverter) * To avoid AS RF beam being too close to OMC REFL RF QPD 2, we can play with moving optics slightly * Clearance of 2 cm should be enough * No periscope is needed for squeezing injection (to-be-viewport flange is already 210 mm heigh) * squeezing beam require 78 mm dia. pedestal |
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| * Update the layout to include periscopes and a beam diverter, add a wedge to OSTM and upload the layout to JGWdoc [Huali] * OSTM is 100 mm dia, 30 mm thick, with wedge of 2 deg * Thicker side is OMC side from the drawing, but actually installed flipped, so thinner side is OMC side (see Fig. 2 of [[https://klog.icrr.u-tokyo.ac.jp/osl/?r=30159|klog #30159]]) * Find OMC shroud drawing [Michimura] * https://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=15840 * https://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=15865 * https://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=16104 * Updated layout will be shared with relevant people for comments [Michimura] * Collect information for REFL and start the REFL layout planning (... and POP next) [Michimura] * Next meeting: TBD on the week of March 24, with a new student |
* Reduce the size of the breadboard to 800 mm dia, and add RF PD layout for REFL [Ryan] * Slightly update the layout to have more space between AS RF beam and OMC REFL RF QPD [Huali] * Check IFI chamber layout if POM2 the beam is hitting the center of POM2 [Michimura] * Next meeting: TBD on the week of April 21+ |
In-vac PD/QPD layout meeting 2025/03/31
Time: Mar 31, 2025 14:00-14:45
Participants: Ray-Kuang Lee, Huali Chen, Ryan Yang, Yoichi Aso, Yuta Michimura
Zoom meeting
Minutes
- REFL (Ryan)
- In-vac RF QPD path almost finished, need info for RF PD path
- RF PD path
- Beam size at RF PD should be around 0.1 mm radius. But avoid putting RF PD at the waist to avoid PD reflected beam mode-matching to the main beam and causing scattered light noise.
Footprint for RF PD is 125 x 58 mm https://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=16111
- RF QPD path
- Waist size of 0.25 mm radius, and beam radius of sqrt(2)*0.25 mm at RF QPDs are consistent with in-air design
- Pedestal size
- Right now using 78 mm dia pedestal, but for 4 inch height optics, we will not use this.
- Since we don't have the design yet, let's copy LIGO design for 4 inch height optics.
Mounting base can be Thorlabs BA1/M with 20 mm dia. posts
- Slightly tilt RF PD and RF QPD so that we can damp the PD/QPD reflected beams
- Let's aim for 800 mm dia. optical breadboard size inside the PD chamber
- AS (Huali)
- Updated the layout based on the comments from the last meeting (OSTM wedge, periscope and distance traveled within periscope, beam diverter)
- To avoid AS RF beam being too close to OMC REFL RF QPD 2, we can play with moving optics slightly
- Clearance of 2 cm should be enough
- No periscope is needed for squeezing injection (to-be-viewport flange is already 210 mm heigh)
- squeezing beam require 78 mm dia. pedestal
A/I
- Reduce the size of the breadboard to 800 mm dia, and add RF PD layout for REFL [Ryan]
- Slightly update the layout to have more space between AS RF beam and OMC REFL RF QPD [Huali]
- Check IFI chamber layout if POM2 the beam is hitting the center of POM2 [Michimura]
- Next meeting: TBD on the week of April 21+