The oplev p/y sensing coupling was optimized long time ago. SInce recently we compare AA diagonalized signal with oplev signal. We decide to check again the oplev p/y coupling again.
The PR and INPUT have not obvious p/y coupling as shown in the attached figure 1 and 2. But there is coupling for end mirror (as shown in the attached figure 3), which was removed by putting PSD rotation angle to be zero (as shown in the attached figure 4).