[Nagano, Nakano, Nagano]

For IMC WFS, we masured beam profile on IMC WFS pass.
The result plot was shown as the attached figure.
(Zero is set at the 2nd lens position on IMC WFS pass.)
Seesing this result, we noticed that the Rayleigh range was too short.
Short Rayleigh range is not expected to make robust WFS system against lens positions, focal length, and so on.
Thus we decided to redesign the WFS beam profile, make longer Rayleigh range (larger beam waist).