Beam quality of SHG generated laser source for FLIM

Posted by Heping Yuan on
URL: http://confocal-microscopy-list.275.s1.nabble.com/Beam-quality-of-SHG-generated-laser-source-for-FLIM-tp7586574.html

*****
To join, leave or search the confocal microscopy listserv, go to:
http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
Post images on http://www.imgur.com and include the link in your posting.
*****

Hi everyone, our application is FLIM microscopy with a pulsed visible source. Since we have a 100 fs Ti-Sapphire laser, we thought we could generate our pulsed source using a BIBO crystal (10 mm thickness). We end up getting very high SHG conversion for 960 nm -> 480 nm (300 mW average power at 480 nm) but when we try to focus this beam down we cannot get anywhere close to a diffraction limited performance. Does anyone have experience using frequency doubled laser source for imaging? What can we do to 'clean up' this frequency doubled beam and how much power can we expect to lose?

Thanks for any help,
Tim