New temperature = 29.03ºC
New current = 1.985A

Beat note strength = -4dBm

Sheila Nutsinee Kara Daniel Richard

Before removing the old laser, we checked a variety of apperatures on the squeezer table.  We realigned the two irises that are in the path in front of the SHG, and also found that there was a beam (reflction from the 50/50 dump BS11 here) that was not dumped and hitting the back side of MR9 in the beatnote path, so Kara added a dump.  We also added dogs to mark the base plate location before removing the laser. 

After setting the new laser in, we were hitting the side of the Faraday apperature and missing the EOM input aperature horizontally.  Using all three knobs on MR1 (steering mirror right after laser), we were able to translate that mirror enough to clear the EOM and hit the first iris in the SHG path reasonably well, then we were able to see some very high order flashes in the SHG.  We continued walking the beam with the three knobs on the first mirror until the SHG was well aligned to the 01 mode, then we were able to see the beatnote.  We adjusted pitch a bit using the BS just after the EOM (BS1), and then using the camera connected to Nutsinee's laptop we could see while scanning the SHG that there were two 00 modes, meaning that the new laser was running multimode at the temperature where we found the beatnote.  We then lowered the current to park half way between 2 mode hops, adjusted the temperature to find the beatnote again, and saw that we were mode hopping again, and increased the current again to find a spot where we seemed to be far from mode hopping and have the beatnote at approximately the correct temperature. Nutsinee adjuted the beatnote alignment a little.

Below is a table of the ratio comparing various powers before and after the swap.  There is a bit more power out of the laser, the SHG efficiency is better, the CLF efficency through the AOMs seems to be a bit better, but the coupling into the fiber is a bit worse so we end up with a similar amount of power in the CLF. We didn't check the seed coupling efficiency before starting.  We can try to go back and improve the coupling into the CLF fiber next Tuesday, but for now the squeezer seems to be back to locking normally.