Search the CONFOCAL archive at
http://listserv.acsu.buffalo.edu/cgi-bin/wa?S1=confocal

The the Zeiss LSM510 series can be supplied with a so called monitor 
diode. This diode gives a relative laser power signal as an extra 
channel in your image. It can be used to normalise your image pixel by 
pixel. In our FRAP experiments we saw nice correlations between 
fluorescent fluctuations and the laser power fluctuations.

Kind regards,
Gert van Cappellen
Optical Imaging Centre Erasmus MC, Netherlands
www.erasmusmc.nl/oic

Peng Xi schreef:
> Search the CONFOCAL archive at
> http://listserv.acsu.buffalo.edu/cgi-bin/wa?S1=confocal
>
> Hi,
>     Does anybody know how the laser intensity is monitored in a commercial 
> confocal system? How the laser fluctuation (they are very small,+/-3%) affects 
> the fluorescence image collection? How it is corrected if it exists?
>     Thank you!
>
> Sincerely,
> Peng Xi
> Purdue University Cytometry Laboratories
> Bindley Bioscience Center
> 1203 W. State Street
> West Lafayette, IN 47907
> Tel: 765-494-0757
> Fax: 765-494-0517
> http://web.ics.purdue.edu/~pxi
>