Y-End TX Module Maintenance was performed today.
Everything went fairly well while following the instructions laid out in T1600436 -V12 Except the AOM Rejected Power measurement. This measurement inbetween PBSC2 and beam dump 2 is measuring the AOM power that we were dumping on to the beam dump. It didn't ever give us a static value like all the rest of the measurements. The max was a 18.5 mW jump right after the we opened the shutter. Then the power would decay down to a lower value of 13.6 mw but over several minutes. The decay rate seemed to get longer after a while. The excitations were indeed turned off. We had zeroed the low power sensor with a shuttered background measurement. I'm not sure why that seemed to not be a steady number. We ended up taking the number that seemed like it had initially asymptote to before we saw the slow fall off.
The Beam Spots all look great. TX Sphere might be very slightly to the right of perfectly center, but I think it's fine.
OLTF went well, Setup was well documented.
Date | May , 21,2025 |
Laser Shutter Check | pass |
Max OFS Offset | 8 |
95% OFS Offset | 7.6 |
Operating OFS Offset | 3.8 |
Laser Output Power | 1.94 W |
After-Laser Rejected Power | 4.11 mW |
AOM Input Power | 1.91 W |
Max Diffracted Power | 1.60 W |
Un-Diffracted Power | 0.285 W |
AOM Diffraction Efficiency | 83.77% |
After-AOM Rejected Power | 15.5 mW |
TxPD Power | 6.51mW |
OFSPD Power | 6.64 mW |
Outer Beam Power | 0.355 W |
Inner Beam Power | 0.352 W |
Output Beam Power Ratio | 0.991549295774648 |
OFS Gain | 38.5 |
OFS Phase Margin | 58 |