The CHETA X arm table telescope was fully aligned as described in gitlab. The performance of the telescope was determined by profiling the beam after L2 and calculating the complex q factor. The profile was measured using the nanoscan beam profiler over a 55cm range between M4 and M5.
This unit was profiled twice the first with a slight angle on L1 to prevent back reflection and then with a reduced angle to determine if this was detrimentally effecting the beam propogation. A non-linear fit was used in both cases to find the q factor which was propogated to the ITM to determine ITM beamsize. Both results show the horizontal axis have a large deviation from the expected q factor and the beamsize at the ITM is reduced by ≈35% and reducing the angle had a minimal effect.
| w0 [um] | z0 [mm] | w @ ITM [mm] | |
| Small angle on L1 | |||
| Horizontal fit | 1486.4±180.5 | -2448.4±269.1 | 36.919 |
| Vertical fit | 916.3±86.3 | -1177.2±143.0 | 57.818 |
| L1 normally incident | |||
| Horizontal fit | 1456.4+/-92.7 | "-2428.4+/-149.4" | 37.659 |
| Vertical fit | 1065.3+/-49.8 | -1384.2+/-79.3 | 50.019 |
Unit 0922 is noticibly non gaussian, screenshot attached, which we believe is consistent with what was observed by thorlabs and is indicated in a paper datasheet shipped to us with the unit. We believe this may be contributing to the deviation from the model.
