Displaying report 1-1 of 1.
Reports until 10:21, Wednesday 10 October 2018
H1 AOS (SQZ)
terry.mcrae@LIGO.ORG - posted 10:21, Wednesday 10 October 2018 - last comment - 12:22, Thursday 11 October 2018(44462)
Mode match adjustment on ISCT6 for TTFSS beat note path

Terry, Nutsinee

There was an error in the previous mode matching solution that contributed to a miserable -23 dBm beat-note signal at the detector. The solution (attached) still gives a fairly miserable -16 dBm beat-note. However maintenance Tuesday finished before it was fully optimized and I was concerned about bumping into the HEPI by HAM6 now that ISCT6 is in its final position. There is also maybe an issue of saturation with .7mW from the Mephisto path and .5mW from the PSL path (detector should have a 1 mW max.) a change of beam-splitter should fix this if necessary.

To minimize squeezer down time from table work I intend to address this when we install the amplitude modulator (to measure the TF from pump modulation to OPO phase modulation), and replace the PSL table fiber (with APC) and add a motorized waveplate and flipper to SQZT6 (to replace the manual versions), probably Thursday.

Non-image files attached to this report
Comments related to this report
terry.mcrae@LIGO.ORG - 12:22, Thursday 11 October 2018 (44493)

The 1611 detector was definitely saturated at 1.2 mW. Attenuating the power to 0.4mW had about similar RF beat-note power (~ -20dBm) and the DC readout voltage also made sense (~ -3.3V, instead of -1.5V at 1.2mW of power). Next put in appropriate beam-splitter to optimize power at somewhat less than 1 mW.

Displaying report 1-1 of 1.