Wen, Naoki, Camilla

As reported in alog65392, the fiber coupling for seed was 50%. By tweaking two lens positions, we improved it to 18.9mW/26.2mW = 72%.

After that, we measured the seed power at OPO reflection/transmission in SQZT7 when OPO is locked/unlocked with IR dither. The offset of PD was 3mV. When OPO is locked with IR dither, the seed power at OPO reflection and transmission are 3.14V and 0.11V, respectively. When OPO is unlocked, the seed power at OPO reflection is 3.34V, while the seed power at OPO transmission is very small. Ideally, the seed power at OPO transmission with IR dither locked should be 3.34V-3.14V = 0.2 V, but it was 0.11V. This discrepancy could be due to the loss inside OPO, but we should investigate it.