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You can check this:

http://www.ldgi-xcite.com/products-xr2100-xp750.php

We use a similar meter from Coherent, but i'm not in the lab now and can't tell you the model #.  We routinely use power at the focal plane with up to 20x objectives. Not sure how accurate it would be with high NA… depends on how close you can get to the objective…

Julio Vazquez. 


----- Original Message -----
From: "John Oreopoulos" <[log in to unmask]>
To: [log in to unmask]
Sent: Tuesday, March 12, 2013 9:09:35 AM
Subject: Re: Laser power meter and sensor

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Hi Martin, it regards to question 2, I don't think such a power meter exists (although if someone else knows otherwise, I'd love to know as well). You're better off measuring the power at the back of the objective (ie: unscrew the objective and measure the power at the empty nosepiece), and then use the wavelength transmission curve of the objective (usually available from the manufacturer) to calculate the percentage of light that gets through to the front end of the objective - some error is introduced here as there is some variability in the transmission for each identical objective, but at least you get a good estimate of the actual power on the other side of the objective.

You might also consider over what area that power that gets to the other side of the objective is projected to determine the power density (power per unit area), which is is a more relevant parameter. There is a nice Nature Protocols paper from 2008 that talks about these kinds of measurements, and there is mention about choice of power meter I think:

Grunwald, D., et al., Calibrating excitation light fluxes for quantitative light microscopy in cell biology. Nature Protocols, 2008. 3(11): p. 1809-1814.

Cheers,

John Oreopoulos
Staff Scientist
Spectral Applied Research
Richmond Hill, Ontario
Canada
www.spectral.ca


On 2013-03-12, at 11:17 AM, Martin Seem wrote:

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> To join, leave or search the confocal microscopy listserv, go to:
> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
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> 
> A couple of questions for the list:
> 
> 1, We are currently in the process of buying a new laser power meter that will 
> primarily be used to check the general stability and power output of the laser 
> lines of our CLSMs. Have anybody recently bought a power meter after 
> considering some of currently offered products (like the Coherent LabMax 
> TOP, Newport 1918-R, GigaHertz PT-9610 and Ophir Vega). Which one did 
> you choose and why?
> 
> 2, Are there any commercially available laser meter sensors that will allow us 
> to measure the actual laser light output from a high NA (NA>1) water or oil 
> immersion objective? 
> 
> Martin