Second faraday isolator seems to be broken

[Aritomi, Yuhang]

This is work on last Friday.
After winter holiday, the second faraday isolator seems to be broken.
Figure 1 shows the transmission of the second faraday isolator.
The beam shape is strange though the beam seems to go through the faraday isolator.
So we removed the isolator and a half wave plate right after it as shown in figure 2.
After re-alignment of SHG, mode matching of SHG is 1.5/(1.5+0.08)= 95% as shown in Figure 3.
We plan to buy a new isolator.