Betsy, Sheila, Jennie W,
This morning Betsy and I removed the viewport cover on the -Y, -X upper port of HAM1. We pointed a laser pointer at REFL WFS A and B, and saw similar DC counts on each of them, with WFS A channels responding when I pointed the laser pointer at the +X diode and WFS B responding to the the -X diode. We were also able to point the laser pointer at LSC REFL B and LSC POP, and both responded. We can't reach LSC REFL A, but we know that diode is responding. POP X is not easily accessible this way, although we might be able to reflect off PM1 to hit that diode.
Jennie W and I went back with the Nikon D810 from Keita's office. We expirimented with different settings on the camera, and taking photos with illuminators and table lights on and off. A few photos are attached, you can see IR light on the barrel of the beamsplitter that splits the beam between WFS A and WFS B. There is also a glint on the mount of the second lens on the sled.
Gabriele and I went out and took some more photos. We also pulled the viewport cover from the +Y -X side of the chamber, (the lower level), and we have a side on view of POP X. We saw a signal when we pointed the laser pointer at the diode. We ran a raster on PM1, but do not see any beams. We also took some photos of LSC POP from the other side of the chamber, these also show no beams. (LSC showing no beam and a tiny glint above and in the +x direction from the diode, caught twice. )
We also took some photos of the LSC pop diode with the illuminator off, they are just black.
We got photos of the glint of the REFL WFS sled BS, with and without offsets on RM2, they look about the same. (here and here)
