Reports 1-1 of 1 Clear search Modify search
AdV-DET (Output mode cleaner)
berni, gouaty - 16:20 Tuesday 31 January 2023 (58646) Print this report
OMC strongly misaligned

This morning Francesco performed a couple of OMC scans with the ITF in single bounce beam. Fig.1 shows the two scans.

The first scan (Fig.2) (10h50 - 11h12 utc) was performed right after Francesco realigned and relocked the cavities, before setting the single bounce. Fig.3 shows a zoom on one FSR:

The power in the carrier TEM00 (52 uW) is only half of what we normally get when the OMC is correctly aligned. The first order mode has 36 uW and the second order mode has 18 uW. Thus the sum of the first and second order mode is higher than the TEM00 power. This indicates a clear misalignment of the OMC. It is probably not possible to make a clear assessment on the mode matching with such a large misalignment.

During the second scan (11h30 - 11h52 utc) (Fig.4) the power in the TEM00 was even smaller, indicating that the misalignment was even worse, probably because of a misalignment of the single bounce beam.

The bottom line is that the OMC needs to be realigned in single bounce. Then another OMC scan should be performed in order to assess the level of the mode matching.

Images attached to this report
Comments to this report:
gouaty - 18:48 Tuesday 31 January 2023 (58652) Print this report

Looking more closely at the first order mode, it seems that the OMC misalignment is mostly vertical.

Images attached to this comment
Search Help
×

Warning

×