Attached below are images of the HR surfaces of the H1 ITMs with IR light resonating in the arms (19.7 W of 1064 nm laser light).
They were captured by Jeff Bartlett a few weeks ago using the "Pcal" ITM camera systems mounted on the spools at the ends of the beam tube manifolds in the LVEA, near the cryopumps.
The camera settings were:
ITM-X
#109 ISO 800, shutter 1/800
#110 ISO 800, shutter 1/400
ITM-Y
#016 ISO 400, shutter 1/500
#110 ISO 250, shutter 1/200
The assembly drawing for the camera system is LIGO-D1500073-v9.
Kentaro Mogushi's technical note regarding camera system upgrades to minimize aberrations introduced by the vacuum windows is LIGO-T1700540-v3.
Note that these are the first IR images after implementing Kentaro's upgrades. Image quality may improve slightly as the systems are adjusted.
Gabriele and I were curious as to the exact locations of the spots on these images. I played with the brightness and contrast of ITMY until I could see some fiducials of the cage structure (in this case, the EQ stops on the right hand side of the image - see first attached image). Then, I super-imposed this on an old image of ITMY from aLOG 42520 that showed the cage structure much more clearly. The results are attached:
The camera position is fixed (physically locked down), the suspension cage is also fixed, and the position of the heads of the EQ stops are well known. By using the EQ screw heads as the zero position, the location of spots on the optic face can identified. I made a conscious decision in these frames to turn down the exposure to accent the surface spots. In most the position of the EQ screw heads are visible.
Here's ITMX blended with images from aLOG 43174 and aLOG 42774
