Rahul, Ryan, Sheila

Today we think that we found a rapid way to iterate the psams preloading, and we made a couple of changes for ZM4.  

Frst Ryan and I measured the beam profile with ZM5 psams servo set to -8V, and ZM4 psams PZT votlage at 0V,  

Rahul can add the details of how he did this, but he added about 1/8 turn of torque to the ZM4 psams.  We then turned the laser back on, and took a beam profile measurement.  Unfortunately the profiler software got into a strange state where the beam waist seemed to be at a very different position and it would not calculate the original beam parameters.  We thought this was because the beam profile had changed dramatically, and Rahul backed off the preload by 1/8 of a turn.  As we were remeasuring the profile Ryan S noticed that the range of the translation stage displayed on the screen went only from 0-100mm, while it normally goes from 0-200mm.  The software would not allow Ryan to reset the measurement range parameter, until we powered the profiler off, exited the software, and started both up again.  

After this, we saw that indeed we had a reasonable q measurement, although not really an improved mode matching. It does seem promising to adjust ZM4 this way, as each iteration took about 30 minutes including our confusion about the beam profiler.