Sheila, Naoki, Vicky
Last week we aligned the pump AOM and fiber in alog71875, but the alignment procedure was not correct. Today we realigned them with correct procedure.
Procedure for pump AOM and fiber alignment:
1) set the ISS drivepoint at 0V to make only 0th order beam and check 90% of AOM throughput with power meter. The measured AOM throughput was 33.8 mW/36 mW = 94%.
2) set the ISS drivepoint at 5V and align the AOM to maximize the 1st order beam. After the AOM alignment, the 1st order beam was 11 mW and the 0th order beam was 23 mW. We measured again the AOM throughput including both 0th and 1st order beam. The AOM throughput was 36 mW/38 mW = 95%.
3) set the ISS drivepoint at 5V and align the fiber by maximizing the H1:SQZ-OPO_REFL_DC_POWER.
4) adjust the OPO temperature by maximizing the H1:SQZ-CLF_REFL_RF6_ABS_OUTPUT.
After this alignment, the SHG output is 42.7 mW, the pump going to fiber is 20.5 mW, and the rejected power is 2.7 mW. The ISS can be locked with OPO trans of 80 while the ISS control monitor is 4.2, which is in stable region.
Regarding 2), we maximized the +1st order beam, which is left side of 0th order beam looking from the laser side of SQZT0.