Mitsuhashi, Shalika-san
What we did:
1. We measured the beam propagation after AOM and LB1909-C. When we measured it, we used PBS, WHP and QWP.
The result was as fellows and attached.
| Position X[mm] | Major Beam Radius[mm] | Minor Beam Radius[mm] |
| 115 | 0.299±0.003 | 0.204±0.002 |
| 170 | 0.321±0.002 | 0.229±0.002 |
| 182 | 0.314±0.002 | 0.2450±0.004 |
| 202 | 0.339±0.002 | 0.259±0.003 |
| 249 | 0.383±0.005 | 0.320±0.005 |
| 280 | 0.450±0.009 | 0.366±0.009 |
2.We set EOM following the above results. The picture was attached. We put QWP and HWP before EOM to meet the requst of EOM about polarization.
We confirmed that the beam power after EOM was maximized, and measured the beam shape to check whether higher-order mode are there or not.The result was attached.
We thinked that higher-order mode are not there.
What we will do next:
We will adjust the design for the cavity following the above reults. And we will measure the beam propagation after EOM, and put a isolator to pick off the erorr signal from the cavity.
