By moving the lens position, I could improve the matching from OPO transmission(BAB) into AMC to a decently high level. This will improve our losses situation by roughly 4.5%. Before, the matching of this beam was roughly 95%. Now it is (1.3680-0.0068)/1.3680 = 99.50%

In the attached figure 2, there is some residual s-pol(actually it is p-pol, but we put a half-wave plate. So this residual beam becomes p-pol when it arrives AMC). But it comes from the defect of PBS.