Participant: Eleonora and Yuhang.

For the locking of main laser with two auxiliary lasers, we need to use part of mian laser.

So we used a 70:30 BS, which is now put after the first BS 25cm. The transmission is 21mW and reflection is 11mW. After put it, we aligned the two steering mirrors so that we can have infrared beam aligned in the filter cavity.

After locking the filter cavity, we can have infrared transmission as 900mV.