Align the infrared beam

Today I and Tomura-san tried to do something about aligning the infrared beam.

Firstly, we try to lock the cavity with green beam. The height peak is 1V. After locking the transmitted signal is also 1V. We didn't change anything else but the EOM for filter cavity.

(Because we need to put a case on the top of our bench. The base plate of EOM for filter cavity excesses the boundary. So we change the base plate angle and align it agin.)

Secondly, we follow the procedure of yuefan. We made sure the laser hit on the right position of the membrane of PR chamber. And we also change the height and angle of camera. Then we can see the signal as attached. We supposed that it's the halo as yuefan mention in the procedure. We tried to moved the camera around to find the laser point and we failed. Note here, we can see only a part of the halo. That means we can see only the shape as a sector. I think the reason maybe the incident angle. And I tried to change the incident angle, but find nothing more. I will try to figure out how to find the beam tomorrow.