40m QIL Cryo_Lab CTN SUS_Lab TCS_Lab OMC_Lab CRIME_Lab FEA ENG_Labs OptContFac Mariner WBEEShop
  Cryo Lab eLog  Not logged in ELOG logo
Message ID: 2809     Entry time: Tue Sep 7 10:01:39 2021
Author: shruti 
Type: Update 
Category: PSOMA 
Subject: attempt at bonding, another broken cantilever... 

Attachments 1 and 2:

The cantilever clamp with a cantilever on it to be used on an optical post. This will replace the non-transmitting flat mirror in the PSOMA cavity. There are two screw holes to mount the optical post, but it would only be possible to use one, therefore this will be initially mounted asymmetrically.

Attachment 3:

Cantilever with the two flat mirrors from Zach's setup. Without having it properly mounted, I could only very crudely measure its reflectivity as R>81% using a power meter.

The one on the left is shown with (what I believe, by comparing to the curved optic in our present setup, is) its HR surface facing up and the one on the right with its AR coated surface shown.


Attachment 4:

I attempted to bond the mirror to the cantilever with cryo-varnish after testing that it bonded two pieces of silicon.  The HR surface which would be facing the interior of the cavity was the side I decided to put the varnish on because the pictures from Zach's thesis depicted the cantilevers that way. I coated the edge of the square-shaped hole on the cantilever head with the varnish and placed the mirror on it. I placed a lens wipe on top of the mirror and then another flat optic over it. While applying pressure on it with a tweezer the cantilever broke (possibly because the aluminium foil below it was very crinkly which I didn't think too much about beforehand).

While the mirror seems to have bonded after a couple of minutes of holding it down, I probably have to remove the varnish (with IPA/acetone I think ?) and re-bond to a different cantilever.

Attachment 1: CAA96DEB-236A-4BD4-B196-8985374562AB.jpeg  3.709 MB  Uploaded Tue Sep 7 11:02:53 2021  | Hide | Hide all
Attachment 2: 03813DE5-AC9D-4958-A203-60B0C8751BCC.jpeg  3.258 MB  Uploaded Tue Sep 7 11:03:02 2021  | Hide | Hide all
Attachment 3: CA57BFB3-9A8C-4AAF-ADA0-F11F507D8464.jpeg  2.547 MB  Uploaded Tue Sep 7 11:03:09 2021  | Hide | Hide all
Attachment 4: B458F0DC-8BD8-422B-9F21-88CF18163C0B.jpeg  2.631 MB  Uploaded Tue Sep 7 11:03:18 2021  | Hide | Hide all
ELOG V3.1.3-