J. Kissel

After conferring with Sina about the results from LHO:89047 and armed with the plan described at the tail end of LHO:89099, went into the optics lab to improve the rapid iteration of beam waist diameter measurement by concocting an optical layout that can measure the beam at two z positions at the same time.

See attached diagram and physical setup.

Note -- the optical table has become over populated with in-vac EOM crystal characterization (and additional beam-scanning set up), so Keita and I shared space by having his setup be at 3 inch beam height and me at 4.5 inch setup. This just barely cleared his beam scan, so I intend to further increase my beam height to 5 inches.

I only have preliminary results (without having changed the collimator lens position at all yet), but they showed hints of astigmatism, so I suspect:
    - the polarization of the emitted beam from the fiber collimator
    - the beam splitters
    - clipping on the beam scan from Keita's setup.

Will confer with the team.