I set up instant green oplevs for ITMs.
A green laser pointer has been set on each end table. It illuminates the ITM center. The beam goea through the ETM substrate.
The reflected green beam returns to the ETM if the ITMs are aligned. Even though the reflected beam to the end is too big, this can
be a rough reference for each ITM.
Note: The green laser pointer at the ETMX were borrowed from Frank. We must return it to him when we finish the work.