Attached is a picture of MC2 Trans QPD during the initial alignment when I devised a setup that used a red laser pointer to mimic the IMC beam, to align the MC2 Trans QPD.
In the images, there are three beams.
Through careful evaluation, Keita and I determined that the upper left beam is the second internal reflection from MC2 (vertical wedge), the far right beam is a reflection from the black glass that's behind the curved steering mirror to the QPD, and the center beam (slightly clipped on the edge of the QPD aperture, since it was not yet aligned) is the real MC2 transmitted beam that we want to center on the MC2 Trans QPD.
Tests to evaluate the likelihood that the alignment into the IMC could be altered in such a way that one of the two beams we do not want to use ends up on on MC2 Trans QPD are under way.
confirmation that currently the wrong beam is centered on MC2 trans: on the left: refl has a beam, MC2 Trans is less than 0.15 on each quadrant: on the right: refl has no ligh, MC2 Trans quadrants are reading signals around 1.5
Realized my snapshot of StripTool did not include enough info - updated dataviewer plot attached.
