After check everything is fine, I proceed to put 98:2 and total reflect mirror.(As attached Fig. 1)
1. I checked the beam parameter, we want beam raidus as 1450um. But we have only 1100um now. (See Fig. 2) I am wondering why it doesn't match the simulation in e-log 791. Here the power should not influence a lot. Because I just increase it from 10mW to 30mW. This is confusing.
2. I tried to align the beam to fiber. I got only 30uW (total is 11mW), means only 0.3% couple. I have tried my best. On the multi-meter, the shown number is very stable(I didn't use 50Om). But the shown number on the power meter is changing a lot. (See Fig3 and 4)