Posted by
mcammer on
URL: http://confocal-microscopy-list.275.s1.nabble.com/How-to-calculate-an-estimate-of-power-density-for-laser-illumination-tp7580574p7580596.html
*****
To join, leave or search the confocal microscopy listserv, go to:
http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy*****
The graphs at
http://cammer.net/historical/aif/instructions/fluor-ref-slides/40X.htm from more than ten years ago show a quick comparison of the importance of measuring throughput at the specific wavelengths you are using. The graph only shows relative throughputs for the 40X objectives we had in the lab at the time, not measured mW, but makes the point.
Now to measure power we put a light meter probe where the sample would be. With high NA objectives we measure through a glass slide or coverslip with oil.
Regards,
Michael
-----Original Message-----
From: Confocal Microscopy List [mailto:
[hidden email]] On Behalf Of Richard Cole
Sent: Monday, July 01, 2013 9:01 AM
To:
[hidden email]
Subject: Re: How to calculate an estimate of power density for laser illumination ?
*****
To join, leave or search the confocal microscopy listserv, go to:
http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy*****
It is imperative to include the objective lens in any power measurement (completely agree with others responding). The most accurate method is to use two similar objectives, both focused on the same area but from opposite sides, measuring the power at the back aperture of the second objective (infinite corrected objective make this much easier). If you want more info just shoot me an email.
Cheers
Rich
Richard Cole
Research Scientist V
Director: Advanced Light Microscopy Core Unit Wadsworth Center
Research Assistant Professor
Dept. of Biomedical Sciences
School of Public Health State University of New York
P.O. Box 509 Albany N.Y. 12201-0509
518-474-7048 Phone
518-474-4430 Fax
Email <mailto:
[hidden email]>
[hidden email]
Website <
http://www.wadsworth.org/cores/alm/index.htm>
www.wadsworth.org/cores/alm/index.htm
Browse the <
http://lists.umn.edu/cgi-bin/wa?LIST=CONFOCALMICROSCOPY>
CONFOCALMICROSCOPY online archives.
<
http://www.lsoft.com/products/listserv-powered.asp> Powered by the LISTSERV Email List Manager