Dhruva, Nutsinee, Naoki

We aligned the pump AOM and fiber. The pump fiber coupling is 43%. We also optimized the seed fiber polarization. We have ~50% of seed throughput from fiber to SQZT7. 

First we aligned the pump AOM. We set the pump ISS drivepoint at 0V and aligned the AOM to maximize the AOM throughput. The AOM throughput was 62% before alignment and is 90% after alignment. Then we set the pump ISS drivepoint at 5V and aligned the AOM to maximize the +1st order beam. After we aligned the pump fiber, the pump before fiber is 21.6mW, the pump OPO REFL is 3.05mW, and the pump OPO REFL rejected is 1.55mW with OPO unlocked. Given the 50:50 BS for SK path, the pump fiber coupling should be (3.05+1.55)*2/21.6 = 43%.

In 75951, we found that the seed launch power increases when the seed shutter is open. Today we found that it is due to the backscattered seed from the seed fiber coupler. We blocked the backscattered seed and now the seed launch power doesn't change with the seed shutter.