It might have, so I think I need to estimate shift of beam spot more preciely.
According to Steve's drawing, radius of the hole of the baffle is 19.8 mm.
Intensity distribution of fundamental mode in x axis direction is this (y is integrated out):
.
With the radius of curvature of ETMY of 60 m and the arm length of 37.78 m, the beam width on ETMY is estimated to be 5.14 mm. From this expression of the intensity, , for example. If round trip loss is considered, these values are doubled.
Although maximum shift of beam spot from the ideal spot on ETMY is estimated to be sqrt(6.0^2+(1.7+1.7)^2)=6.9 mm, this value could have error of several tens of % because I am not sure to what exten the calibration is precise, which means that the maximum shift could be ~10 mm and seperation between the baffle and the beam could be ~10 mm.
Therefore, I need to check how much the beam spot shifts with another way, maybe with captured image of the CCD camera.
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