Multi-photon Laser
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To join, leave or search the confocal microscopy listserv, go to: http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy ***** We recently had a service visit from Zeiss and they calibrated our multiphoton laser. It is not linear with relationship to the "slider" bar in ZEN. Has anyone had similar issues with their multi-photon system? It is a Zeiss LSM710 with a Coherent Ultra II laser. Sincerely, Claire |
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To join, leave or search the confocal microscopy listserv, go to: http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy ***** It is either a software calibration issue, which can be fixed by performing a calibration procedure, or the AOM that modulates the laser isn't working right. My guess would be that it is the former. Sometimes people forget to save the calibration profile, or the calibration doesn't 'take' properly into the software for some reason. If another attempt at calibration fails then it might be an AOM hardware problem. Craig Brideau On Wed, Dec 18, 2013 at 2:15 PM, Claire Brown, Dr. <[hidden email]>wrote: > ***** > To join, leave or search the confocal microscopy listserv, go to: > http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy > ***** > > We recently had a service visit from Zeiss and they calibrated our > multiphoton laser. It is not linear with relationship to the "slider" bar > in ZEN. Has anyone had similar issues with their multi-photon system? It is > a Zeiss LSM710 with a Coherent Ultra II laser. > > Sincerely, > > Claire > |
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In reply to this post by Claire Brown
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To join, leave or search the confocal microscopy listserv, go to: http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy ***** Thanks for your input Craig. Here is a bit more detail about our situation. Our Zeiss service people tell us they do the calibration using the standard PMTs in the microscope which only measure up to 700 because of the optical separation on the 710 (non filter based). So they do the calibration at 699 nm but we want it to be linear out into the IR. We are trying to see if there is an issue with their calibration technique as it doesn't seem ideal. That being said when we measure the laser output at 700 nm or 800 nm are not linear. This is after two service visits and calibrations when the service people tell us all is fine. So it is unclear if it is a calibration or AOM issue. Any input would be appreciated. Sincerely, Claire |
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To join, leave or search the confocal microscopy listserv, go to: http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy ***** Rather than relying on detected signal I prefer to measure the power out of the objective, so you actually calibrate against power delivered to the sample. You can get power meters now that fit under your objective, Lumen Dynamics/Exfo and Thorlabs both sell these. I helped develop the Thor one, so I'm not exactly unbiased here. @;-) However, my thinking is that this method takes any non-linearities in your detection path out of the equation so that your power slider setting is accurate to what you are delivering to the sample. With this method you stick the meter under the objective and get a linear ramp of delivered power calibrated against slider position. The meter will accept a drop of oil or water so you can use it with those types of lenses if you want to be super accurate. As a side benefit, when you write a paper and the reviewers ask how much power is on your sample, you will already know. Craig On Thu, Dec 19, 2013 at 2:37 PM, Claire Brown <[hidden email]>wrote: > ***** > To join, leave or search the confocal microscopy listserv, go to: > http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy > ***** > > Thanks for your input Craig. Here is a bit more detail about our situation. > > Our Zeiss service people tell us they do the calibration using the standard > PMTs in the microscope which only measure up to 700 because of the optical > separation on the 710 (non filter based). So they do the calibration at 699 > nm but we want it to be linear out into the IR. We are trying to see if > there is an issue with their calibration technique as it doesn't seem > ideal. > > That being said when we measure the laser output at 700 nm or 800 nm are > not > linear. This is after two service visits and calibrations when the service > people tell us all is fine. So it is unclear if it is a calibration or AOM > issue. > > Any input would be appreciated. > > Sincerely, > > Claire > |
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In reply to this post by Claire Brown
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To join, leave or search the confocal microscopy listserv, go to: http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy ***** This surprises me, our service people always use the power meter, you need to make sure that you are in the linear range of the meter, as you can get several hundred mW of IR power out of the objective with todays lasers. -----Original Message----- From: "Claire Brown" <[hidden email]> Sent: 19/12/2013 21:57 To: "[hidden email]" <[hidden email]> Subject: Re: Multi-photon Laser ***** To join, leave or search the confocal microscopy listserv, go to: http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy ***** Thanks for your input Craig. Here is a bit more detail about our situation. Our Zeiss service people tell us they do the calibration using the standard PMTs in the microscope which only measure up to 700 because of the optical separation on the 710 (non filter based). So they do the calibration at 699 nm but we want it to be linear out into the IR. We are trying to see if there is an issue with their calibration technique as it doesn't seem ideal. That being said when we measure the laser output at 700 nm or 800 nm are not linear. This is after two service visits and calibrations when the service people tell us all is fine. So it is unclear if it is a calibration or AOM issue. Any input would be appreciated. Sincerely, Claire |
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In reply to this post by Claire Brown
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To join, leave or search the confocal microscopy listserv, go to: http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy ***** You can still use your microscope in reflection. For this position a reflective strip on your goal and focus. After that trsè with little power you can check your laser and AOM. With the linearization function you harmonize the AOM with PMT |
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In reply to this post by Andreas Bruckbauer
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To join, leave or search the confocal microscopy listserv, go to: http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy ***** I would be a bit alarmed at 100's of mW of power coming out of the objective (depending on the objective). Normally one wants to scale the power control so that if the user puts the slider to 100%, you get maximum SAFE power out of the objective, rather than the maximum power the laser will put out... Craig On Fri, Dec 20, 2013 at 2:26 AM, Andreas Bruckbauer <[hidden email]>wrote: > ***** > To join, leave or search the confocal microscopy listserv, go to: > http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy > ***** > > This surprises me, our service people always use the power meter, you need > to make sure that you are in the linear range of the meter, as you can get > several hundred mW of IR power out of the objective with todays lasers. > > -----Original Message----- > From: "Claire Brown" <[hidden email]> > Sent: 19/12/2013 21:57 > To: "[hidden email]" <[hidden email]> > Subject: Re: Multi-photon Laser > > ***** > To join, leave or search the confocal microscopy listserv, go to: > http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy > ***** > > Thanks for your input Craig. Here is a bit more detail about our situation. > > Our Zeiss service people tell us they do the calibration using the standard > PMTs in the microscope which only measure up to 700 because of the optical > separation on the 710 (non filter based). So they do the calibration at 699 > nm but we want it to be linear out into the IR. We are trying to see if > there is an issue with their calibration technique as it doesn't seem > ideal. > > That being said when we measure the laser output at 700 nm or 800 nm are > not > linear. This is after two service visits and calibrations when the service > people tell us all is fine. So it is unclear if it is a calibration or AOM > issue. > > Any input would be appreciated. > > Sincerely, > > Claire > |
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