Sheila, Terry, Daniel, Terra, T Vo, Koji, Nutsinee

SQZ beam came back!

This morning we checked that the SQZ beam went into HAM5 and still came back out on the other side to the OMC. The SQZ beam was not perfectly overlapped with the PSL beam but we declared that was good enough.

Double-beam

Corey Austin told us we should expect two beams reflected back from the .5 deg wedged thin film polarizer, we only saw one beam came into HAM6. Koji calculated the separation angle to be 2.2 deg. ZM2 diameter is 2", facing the beam at >45 deg left us with about ~1" diameter (2.5 cm). The beam separation at ~1m is ~4cm. It is very likely that the second beam doesn't hit ZM2 as the main beam hits the center of the optic.

Beam diverter

We moved the beam diverter such that the transmitted red beam from the VOPO shot out of HAM6 to SQZT6 parallel to the green refl and trans. A new back (right) panel for the SQZT6 has to be made, the beam is now 4 and 1/4 inches from the top of the panel and 9 and 1/4 inches from the -y edge of the panel. Here's a photo of the red trans beam position relative to the view port simulator. We also removed the apertures out of the way. Here's a photo of aperture #1 and #2 that shows their positions before we moved it, which was set after the realignment work in HAM5 last week.

IFO beam

The IFO beam that reflected to the squeezer side of HAM6 table measured 7.6 uW and was 6mm above aperture. A black glass beam dump was put behind the beam diverter at roughly 33 deg from the beam diverter's nominal. The sketch shows the angle that the beam came in relative to the beam diverter and how the reflected angle was calculated. The IFO trans beam into OMC measured 1.4mW. We also moved the silicon carbide beam dump to capture the OMC refl beam.