User:Pranav Rathi/Notebook/OT/2010/03/09/Beam Profiling

Steve Koch 01:11, 10 March 2010 (EST): Our notes from today:


 * Beam profiling remains difficult
 * Pranav and Anthony have good evidence (please do upload it!) showing that the beam degrades at higher power. We have four lines of evidence now that the problem is the laser: (1) pictures from today, (2) looking at the OT reflection from the sample plane, (3) the strange behavior on the QPD (less power coming through), and (4) mysteriously weak OT in Evans lab.  I am pretty convinced that the laser is going bad at high power
 * I can show you how to use our file server to put a bunch of files on the internet if you want.
 * Calling Coherent to find out our options for fixing the laser is really important. It would be great if a local tech could fix it with very quick turnaround time.
 * Testing the laser with a cold aluminum block on top is a good idea, to see if it improves beam quality.