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Hi to everyone, I'm using a 2Photon system with a Chameleon, AOM on 
the Zeiss LSM510 system.

After the IR laser has been swtiched on for over an hour, base plate 
stable at 37C, 800nm, I find that when I measure the power using 
either the AOM remote control via the service menu or via the normal 
software, ie by pressing "start". It takes about 7- 10s for the power 
to ramp up to full at the objective. If I measure the power prior to 
the beam entering the microscope the same thing happens.


The same delay is also seen in an exponential bleaching pattern 
(repeatable) for which occurs over the same period for imaging GCamp 
in living tissue, once the "start" button is pressed. I figure the 
exponential intensity  decrease is due to the slow ramping of the 
laser intensity from 0 to full which is, if I've got this right, what 
you would expect for increasing the 2 Photon laser power.


  Hope someone can shed some light on this ( no puns intended)



regards




Francis
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Francis Chee (PhD)
Senior Research Fellow
353 (0) 862044680 (mob)
353 (1) 896 8527 (office)

Trinity College Institute of Neuroscience
Lloyd Building Dublin 2
Ireland
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