Because yesterday's measurement doesn't match previous result. I decided to do the simulation for the infrared. However, I found there is a lens without label on it. So Eleonora suggested me to consult yuefan about this. And yuefan said it is used for the test of mode cleaner. So we decide to remove it. After removing it, we want to check the beam waist again.

See attached figure 1, we found the beam waist was very far from where we did the measurement.(The measurement position is shown on the attached figure 2) And the beam waist is about 1mm. The beam waist fit the result of OptoCad. However the beam waist position doesn't fit the result of OptoCad. As you can see the attached figure 3, the highlight part show that the beam waist is around 8 meters ahead of R1. This R1 is the dichroic mirror which is used to combine green and infrared. But the measurement of beam waist tells us the distance between them is around 6 meters.

According to attached figure1, the beam size at Faraday Isolator should be around 2mm in radius. This measurement is totally different from the requirement of e-log 441. E-log 441 gave us the beam size around Faraday Isolator should be 1.368mm. No matter it is diameter or radius, it doesn't agree what we measured today.

Besides, I just found there is e-log 442 which tells us the setting of infrared telescope. We can see from there, the design is using leses f500, f300 and f350. However I found the actual lenses we are using is f500, f150 and f175. See attached last three pictures to check this.