Aritomi and Yuhang

I found beam was cut obviously at the output port of MZ. The cut position is shown in the attached figure 1.

There is also a very good point to check if the beam is cut or not. In the attached figure 2, the shown place is a round shape. But when the beam was cut, I saw clearly there is an unfilled corner.(I am sorry I didn't realize to take a picture at that time)

In the attached figure 3(cut) and 4(no cut), you can see the difference before and after solving the problem of cutting. The higher order mode becomes a lit bit lower. After that we tried to change the offset of MZ servo, then we found we could reach GRMC transmitted power of 70mW. This meets the requirement of high BAB amplification for filter cavity alignment.