Safe to run multiphoton laser at 100% power for overnight continuous imaging?
Locked
 
|
Moulding, Dale |
Safe to run multiphoton laser at 100% power for overnight continuous imaging?
|
*****
To join, leave or search the confocal microscopy listserv, go to: http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy Post images on http://www.imgur.com and include the link in your posting. ***** Dear list, I've been asked to run our 2 photon laser (Mai Tai eHP DeepSee) at full power (3W) non-stop over night to scan a large sample. When doing ablations we run at 100% and I hadn't even given it a second thought, as the ablations are over in a flash. However, continuously (4 to 16 hours) running 100% 800nM at 3W I'm concerned we may damage the optics of the system. It will be on a Zeiss Examiner, going through Zeiss's 10x0.5 or 20x1.0 water dippers. Has anyone ever imaged / ablated with a 2P laser continuously at full power? Should I be concerned that the objectives may be damaged? Cheers Dale Dale Moulding PhD FRMS ICH Light Microscopy Facility Room W2.06, BDRC office UCL Great Ormond Street Institute of Child Health 30 Guilford St London WC1N 1EH Mob: 07787 699609 Tel: 020 7905 2753 http://www.ucl.ac.uk/ich/core-scientific-facilities-centres/confocal-microscopy |
|
|
Craig Brideau |
Re: Safe to run multiphoton laser at 100% power for overnight continuous imaging?
|
|
*****
To join, leave or search the confocal microscopy listserv, go to: http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy Post images on http://www.imgur.com and include the link in your posting. ***** How are you not destroying your sample at these powers and timescales? This seems rather risky to me. Craig On Tue, Sep 25, 2018, 6:56 AM Moulding, Dale <[hidden email]> wrote: > ***** > To join, leave or search the confocal microscopy listserv, go to: > http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy > Post images on http://www.imgur.com and include the link in your posting. > ***** > > Dear list, > > I've been asked to run our 2 photon laser (Mai Tai eHP DeepSee) at full > power (3W) non-stop over night to scan a large sample. > When doing ablations we run at 100% and I hadn't even given it a second > thought, as the ablations are over in a flash. > However, continuously (4 to 16 hours) running 100% 800nM at 3W I'm > concerned we may damage the optics of the system. It will be on a Zeiss > Examiner, going through Zeiss's 10x0.5 or 20x1.0 water dippers. > Has anyone ever imaged / ablated with a 2P laser continuously at full > power? > Should I be concerned that the objectives may be damaged? > > Cheers > > Dale > > > Dale Moulding PhD FRMS > ICH Light Microscopy Facility > Room W2.06, BDRC office > UCL Great Ormond Street Institute of Child Health > 30 Guilford St > London WC1N 1EH > Mob: 07787 699609 > Tel: 020 7905 2753 > > http://www.ucl.ac.uk/ich/core-scientific-facilities-centres/confocal-microscopy > |
|
|
Ochoa, Lorenzo F. |
Re: Safe to run multiphoton laser at 100% power for overnight continuous imaging?
|
|
In reply to this post by Moulding, Dale
*****
To join, leave or search the confocal microscopy listserv, go to: http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy Post images on http://www.imgur.com and include the link in your posting. ***** Hello Dale, I've ran a 2-P Mai Tai in the past for over 16 hours continuously at 1W power for a long imaging session. I did have a pockel cell to control the power that was actually getting to the sample but in terms of the laser being able to run for that long I had no issues. I haven't notice any damage to the optics so far either. The only problem I've ran into was a loss of communication between the laser and the computer with the control software. Hope that helps. Lorenzo -----Original Message----- From: Confocal Microscopy List [mailto:[hidden email]] On Behalf Of Moulding, Dale Sent: Tuesday, September 25, 2018 7:56 AM To: [hidden email] Subject: Safe to run multiphoton laser at 100% power for overnight continuous imaging? WARNING: This email originated from outside of UTMB's email system. Do not click links or open attachments unless you recognize the sender and know the content is safe. ***** To join, leave or search the confocal microscopy listserv, go to: https://na01.safelinks.protection.outlook.com/?url=http%3A%2F%2Flists.umn.edu%2Fcgi-bin%2Fwa%3FA0%3Dconfocalmicroscopy&data=02%7C01%7Clfochoa%40UTMB.EDU%7Cae1aa8d9d79d4395517508d622e64662%7C7bef256d85db4526a72d31aea2546852%7C0%7C0%7C636734769755876244&sdata=aWnIWQvkLd0iWttfMxPFZvpV00g4Dtl%2FooBGCSHnJfc%3D&reserved=0 Post images on https://na01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.imgur.com&data=02%7C01%7Clfochoa%40UTMB.EDU%7Cae1aa8d9d79d4395517508d622e64662%7C7bef256d85db4526a72d31aea2546852%7C0%7C0%7C636734769755876244&sdata=DuOZDE%2Bq8uzh3qvVLiO7fRf4fGomhVAcV34ISyaTWwI%3D&reserved=0 and include the link in your posting. ***** Dear list, I've been asked to run our 2 photon laser (Mai Tai eHP DeepSee) at full power (3W) non-stop over night to scan a large sample. When doing ablations we run at 100% and I hadn't even given it a second thought, as the ablations are over in a flash. However, continuously (4 to 16 hours) running 100% 800nM at 3W I'm concerned we may damage the optics of the system. It will be on a Zeiss Examiner, going through Zeiss's 10x0.5 or 20x1.0 water dippers. Has anyone ever imaged / ablated with a 2P laser continuously at full power? Should I be concerned that the objectives may be damaged? Cheers Dale Dale Moulding PhD FRMS ICH Light Microscopy Facility Room W2.06, BDRC office UCL Great Ormond Street Institute of Child Health 30 Guilford St London WC1N 1EH Mob: 07787 699609 Tel: 020 7905 2753 https://na01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.ucl.ac.uk%2Fich%2Fcore-scientific-facilities-centres%2Fconfocal-microscopy&data=02%7C01%7Clfochoa%40UTMB.EDU%7Cae1aa8d9d79d4395517508d622e64662%7C7bef256d85db4526a72d31aea2546852%7C0%7C0%7C636734769755876244&sdata=HOf%2BtmkIwJftv7nQiwEyvII9EpbXKRRrX%2BwfpCwXgqo%3D&reserved=0 |
|
|
Armstrong, Brian |
Re: Safe to run multiphoton laser at 100% power for overnight continuous imaging?
|
|
In reply to this post by Moulding, Dale
*****
To join, leave or search the confocal microscopy listserv, go to: http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy Post images on http://www.imgur.com and include the link in your posting. ***** Hi Dale, it depends in part on the wavelength. As I imagine you already know the output power at say 1050nm is far lower than say 800nm. I do not think the LASER "cares" what your output power is. As for the optics I cannot say. I think that they fall off in transmittance above a given wavelength in the IR range but I do not know if this is because of a coating or properties of the lens??? I have heard stories of people burning objectives. Pockels cells will also burn out after around 10 years or so. P.S. How do you like the 10x/0.5 W for 2P work? Brian Armstrong PhD Associate Research Professor Developmental and Stem Cell Biology Diabetes and Metabolic Diseases Director, Light Microscopy Core Beckman Research Institute, City of Hope -----Original Message----- From: Confocal Microscopy List [mailto:[hidden email]] On Behalf Of Moulding, Dale Sent: Tuesday, September 25, 2018 5:56 AM To: [hidden email] Subject: Safe to run multiphoton laser at 100% power for overnight continuous imaging? [Attention: This email came from an external source. Do not open attachments or click on links from unknown senders or unexpected emails.] ***** To join, leave or search the confocal microscopy listserv, go to: http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy Post images on http://www.imgur.com and include the link in your posting. ***** Dear list, I've been asked to run our 2 photon laser (Mai Tai eHP DeepSee) at full power (3W) non-stop over night to scan a large sample. When doing ablations we run at 100% and I hadn't even given it a second thought, as the ablations are over in a flash. However, continuously (4 to 16 hours) running 100% 800nM at 3W I'm concerned we may damage the optics of the system. It will be on a Zeiss Examiner, going through Zeiss's 10x0.5 or 20x1.0 water dippers. Has anyone ever imaged / ablated with a 2P laser continuously at full power? Should I be concerned that the objectives may be damaged? Cheers Dale Dale Moulding PhD FRMS ICH Light Microscopy Facility Room W2.06, BDRC office UCL Great Ormond Street Institute of Child Health 30 Guilford St London WC1N 1EH Mob: 07787 699609 Tel: 020 7905 2753 http://www.ucl.ac.uk/ich/core-scientific-facilities-centres/confocal-microscopy ------------------------------------------------------------ -SECURITY/CONFIDENTIALITY WARNING- This message and any attachments are intended solely for the individual or entity to which they are addressed. This communication may contain information that is privileged, confidential, or exempt from disclosure under applicable law (e.g., personal health information, research data, financial information). Because this e-mail has been sent without encryption, individuals other than the intended recipient may be able to view the information, forward it to others or tamper with the information without the knowledge or consent of the sender. If you are not the intended recipient, or the employee or person responsible for delivering the message to the intended recipient, any dissemination, distribution or copying of the communication is strictly prohibited. If you received the communication in error, please notify the sender immediately by replying to this message and deleting the message and any accompanying files from your system. If, due to the security risks, you do not wish to receive further communications via e-mail, please reply to this message and inform the sender that you do not wish to receive further e-mail from the sender. (LCP301) ------------------------------------------------------------ |
|
|
Claire Mitchell |
Re: Safe to run multiphoton laser at 100% power for overnight continuous imaging?
|
|
In reply to this post by Ochoa, Lorenzo F.
*****
To join, leave or search the confocal microscopy listserv, go to: http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy Post images on http://www.imgur.com and include the link in your posting. ***** Hi Dale We suffered a cracked 10x air objective on our Zeiss 7MP with ~4W Chameleon and this was without imaging at max power for significant amounts of time, only occasional 100% ablation. Luckily Zeiss agreed with me that the objective should be able to withstand the full power of the supplied laser and replaced it but maybe not a good idea if you don't have a service contract? Best wishes Claire -----Original Message----- From: Confocal Microscopy List [mailto:[hidden email]] On Behalf Of Ochoa, Lorenzo F. Sent: 25 September 2018 16:22 To: [hidden email] Subject: Re: Safe to run multiphoton laser at 100% power for overnight continuous imaging? ***** To join, leave or search the confocal microscopy listserv, go to: http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy Post images on http://www.imgur.com and include the link in your posting. ***** Hello Dale, I've ran a 2-P Mai Tai in the past for over 16 hours continuously at 1W power for a long imaging session. I did have a pockel cell to control the power that was actually getting to the sample but in terms of the laser being able to run for that long I had no issues. I haven't notice any damage to the optics so far either. The only problem I've ran into was a loss of communication between the laser and the computer with the control software. Hope that helps. Lorenzo -----Original Message----- From: Confocal Microscopy List [mailto:[hidden email]] On Behalf Of Moulding, Dale Sent: Tuesday, September 25, 2018 7:56 AM To: [hidden email] Subject: Safe to run multiphoton laser at 100% power for overnight continuous imaging? WARNING: This email originated from outside of UTMB's email system. Do not click links or open attachments unless you recognize the sender and know the content is safe. ***** To join, leave or search the confocal microscopy listserv, go to: https://na01.safelinks.protection.outlook.com/?url=http%3A%2F%2Flists.umn.edu%2Fcgi-bin%2Fwa%3FA0%3Dconfocalmicroscopy&data=02%7C01%7Clfochoa%40UTMB.EDU%7Cae1aa8d9d79d4395517508d622e64662%7C7bef256d85db4526a72d31aea2546852%7C0%7C0%7C636734769755876244&sdata=aWnIWQvkLd0iWttfMxPFZvpV00g4Dtl%2FooBGCSHnJfc%3D&reserved=0 Post images on https://na01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.imgur.com&data=02%7C01%7Clfochoa%40UTMB.EDU%7Cae1aa8d9d79d4395517508d622e64662%7C7bef256d85db4526a72d31aea2546852%7C0%7C0%7C636734769755876244&sdata=DuOZDE%2Bq8uzh3qvVLiO7fRf4fGomhVAcV34ISyaTWwI%3D&reserved=0 and include the link in your posting. ***** Dear list, I've been asked to run our 2 photon laser (Mai Tai eHP DeepSee) at full power (3W) non-stop over night to scan a large sample. When doing ablations we run at 100% and I hadn't even given it a second thought, as the ablations are over in a flash. However, continuously (4 to 16 hours) running 100% 800nM at 3W I'm concerned we may damage the optics of the system. It will be on a Zeiss Examiner, going through Zeiss's 10x0.5 or 20x1.0 water dippers. Has anyone ever imaged / ablated with a 2P laser continuously at full power? Should I be concerned that the objectives may be damaged? Cheers Dale Dale Moulding PhD FRMS ICH Light Microscopy Facility Room W2.06, BDRC office UCL Great Ormond Street Institute of Child Health 30 Guilford St London WC1N 1EH Mob: 07787 699609 Tel: 020 7905 2753 https://na01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.ucl.ac.uk%2Fich%2Fcore-scientific-facilities-centres%2Fconfocal-microscopy&data=02%7C01%7Clfochoa%40UTMB.EDU%7Cae1aa8d9d79d4395517508d622e64662%7C7bef256d85db4526a72d31aea2546852%7C0%7C0%7C636734769755876244&sdata=HOf%2BtmkIwJftv7nQiwEyvII9EpbXKRRrX%2BwfpCwXgqo%3D&reserved=0 |
|
|
Craig Brideau |
Re: Safe to run multiphoton laser at 100% power for overnight continuous imaging?
|
|
In reply to this post by Armstrong, Brian
*****
To join, leave or search the confocal microscopy listserv, go to: http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy Post images on http://www.imgur.com and include the link in your posting. ***** You do raise a valid point Brian, the power of most Ti:Saphs varies fairly dramatically by wavelength. The transmission through the optical system will also be different, and what the system considers '100%' may not actually be that much power under certain situations. In most cases, however, a Ti:Saph can produce much more power than is necessary for imaging. Try measuring the power out of the objective when set to 100% to see what you are actually getting; maybe it isn't that much compared to the output of the laser once all the system losses are considered. Craig On Tue, Sep 25, 2018 at 9:41 AM Armstrong, Brian <[hidden email]> wrote: > ***** > To join, leave or search the confocal microscopy listserv, go to: > http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy > Post images on http://www.imgur.com and include the link in your posting. > ***** > > Hi Dale, it depends in part on the wavelength. As I imagine you already > know the output power at say 1050nm is far lower than say 800nm. I do not > think the LASER "cares" what your output power is. As for the optics I > cannot say. I think that they fall off in transmittance above a given > wavelength in the IR range but I do not know if this is because of a > coating or properties of the lens??? I have heard stories of people burning > objectives. Pockels cells will also burn out after around 10 years or so. > > P.S. How do you like the 10x/0.5 W for 2P work? > > Brian Armstrong PhD > Associate Research Professor > Developmental and Stem Cell Biology > Diabetes and Metabolic Diseases > Director, Light Microscopy Core > Beckman Research Institute, City of Hope > > > > -----Original Message----- > From: Confocal Microscopy List [mailto:[hidden email]] > On Behalf Of Moulding, Dale > Sent: Tuesday, September 25, 2018 5:56 AM > To: [hidden email] > Subject: Safe to run multiphoton laser at 100% power for overnight > continuous imaging? > > [Attention: This email came from an external source. Do not open > attachments or click on links from unknown senders or unexpected emails.] > > > > > > ***** > To join, leave or search the confocal microscopy listserv, go to: > http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy > Post images on http://www.imgur.com and include the link in your posting. > ***** > > Dear list, > > I've been asked to run our 2 photon laser (Mai Tai eHP DeepSee) at full > power (3W) non-stop over night to scan a large sample. > When doing ablations we run at 100% and I hadn't even given it a second > thought, as the ablations are over in a flash. > However, continuously (4 to 16 hours) running 100% 800nM at 3W I'm > concerned we may damage the optics of the system. It will be on a Zeiss > Examiner, going through Zeiss's 10x0.5 or 20x1.0 water dippers. > Has anyone ever imaged / ablated with a 2P laser continuously at full > power? > Should I be concerned that the objectives may be damaged? > > Cheers > > Dale > > > Dale Moulding PhD FRMS > ICH Light Microscopy Facility > Room W2.06, BDRC office > UCL Great Ormond Street Institute of Child Health > 30 Guilford St > London WC1N 1EH > Mob: 07787 699609 > Tel: 020 7905 2753 > > http://www.ucl.ac.uk/ich/core-scientific-facilities-centres/confocal-microscopy > > ------------------------------------------------------------ > -SECURITY/CONFIDENTIALITY WARNING- > > This message and any attachments are intended solely for the individual or > entity to which they are addressed. This communication may contain > information that is privileged, confidential, or exempt from disclosure > under applicable law (e.g., personal health information, research data, > financial information). Because this e-mail has been sent without > encryption, individuals other than the intended recipient may be able to > view the information, forward it to others or tamper with the information > without the knowledge or consent of the sender. If you are not the intended > recipient, or the employee or person responsible for delivering the message > to the intended recipient, any dissemination, distribution or copying of > the communication is strictly prohibited. If you received the communication > in error, please notify the sender immediately by replying to this message > and deleting the message and any accompanying files from your system. If, > due to the security risks, you do not wish to receive further > communications via e-mail, please reply to this message and inform the > sender that you do not wish to receive further e-mail from the sender. > (LCP301) > ------------------------------------------------------------ > |
|
|
Moulding, Dale |
Re: Safe to run multiphoton laser at 100% power for overnight continuous imaging?
|
|
*****
To join, leave or search the confocal microscopy listserv, go to: http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy Post images on http://www.imgur.com and include the link in your posting. ***** Dear all, Thanks for the replies. It will be at 800nM, so full power output, and will be continuously firing though the objective for at least 4 hours as it is not for imaging but for catalysis. Zeiss aren't able to guarantee their objectives for this (drilling to the centre of the earth!), so if I do get a cracked lens / glue then I'm not sure our service contract will cover it. @Lorenzo, for your 16 hour experiment were you sending the laser through the objective non-stop for the entire time, or just imaging periodically? @Craig, agreed, it’s a lot of power, but not for imaging, for catalysis. @Brian, I love the 10x0.5 dipper for 2P work. Massive improvement over the 10x0.3. @Claire, I'm not sure Zeiss will cover the damage this time, and haven't really had a definitive answer, unless I've misunderstood them. Cheers Dale -----Original Message----- From: Confocal Microscopy List <[hidden email]> On Behalf Of Craig Brideau Sent: 25 September 2018 17:13 To: [hidden email] Subject: Re: Safe to run multiphoton laser at 100% power for overnight continuous imaging? ***** To join, leave or search the confocal microscopy listserv, go to: http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy Post images on http://www.imgur.com and include the link in your posting. ***** You do raise a valid point Brian, the power of most Ti:Saphs varies fairly dramatically by wavelength. The transmission through the optical system will also be different, and what the system considers '100%' may not actually be that much power under certain situations. In most cases, however, a Ti:Saph can produce much more power than is necessary for imaging. Try measuring the power out of the objective when set to 100% to see what you are actually getting; maybe it isn't that much compared to the output of the laser once all the system losses are considered. Craig On Tue, Sep 25, 2018 at 9:41 AM Armstrong, Brian <[hidden email]> wrote: > ***** > To join, leave or search the confocal microscopy listserv, go to: > http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy > Post images on http://www.imgur.com and include the link in your posting. > ***** > > Hi Dale, it depends in part on the wavelength. As I imagine you > already know the output power at say 1050nm is far lower than say > 800nm. I do not think the LASER "cares" what your output power is. As > for the optics I cannot say. I think that they fall off in > transmittance above a given wavelength in the IR range but I do not > know if this is because of a coating or properties of the lens??? I > have heard stories of people burning objectives. Pockels cells will also burn out after around 10 years or so. > > P.S. How do you like the 10x/0.5 W for 2P work? > > Brian Armstrong PhD > Associate Research Professor > Developmental and Stem Cell Biology > Diabetes and Metabolic Diseases > Director, Light Microscopy Core > Beckman Research Institute, City of Hope > > > > -----Original Message----- > From: Confocal Microscopy List > [mailto:[hidden email]] > On Behalf Of Moulding, Dale > Sent: Tuesday, September 25, 2018 5:56 AM > To: [hidden email] > Subject: Safe to run multiphoton laser at 100% power for overnight > continuous imaging? > > [Attention: This email came from an external source. Do not open > attachments or click on links from unknown senders or unexpected > emails.] > > > > > > ***** > To join, leave or search the confocal microscopy listserv, go to: > http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy > Post images on http://www.imgur.com and include the link in your posting. > ***** > > Dear list, > > I've been asked to run our 2 photon laser (Mai Tai eHP DeepSee) at > full power (3W) non-stop over night to scan a large sample. > When doing ablations we run at 100% and I hadn't even given it a > second thought, as the ablations are over in a flash. > However, continuously (4 to 16 hours) running 100% 800nM at 3W I'm > concerned we may damage the optics of the system. It will be on a > Zeiss Examiner, going through Zeiss's 10x0.5 or 20x1.0 water dippers. > Has anyone ever imaged / ablated with a 2P laser continuously at full > power? > Should I be concerned that the objectives may be damaged? > > Cheers > > Dale > > > Dale Moulding PhD FRMS > ICH Light Microscopy Facility > Room W2.06, BDRC office > UCL Great Ormond Street Institute of Child Health > 30 Guilford St > London WC1N 1EH > Mob: 07787 699609 > Tel: 020 7905 2753 > > http://www.ucl.ac.uk/ich/core-scientific-facilities-centres/confocal-m > icroscopy > > ------------------------------------------------------------ > -SECURITY/CONFIDENTIALITY WARNING- > > This message and any attachments are intended solely for the > individual or entity to which they are addressed. This communication > may contain information that is privileged, confidential, or exempt > from disclosure under applicable law (e.g., personal health > information, research data, financial information). Because this > e-mail has been sent without encryption, individuals other than the > intended recipient may be able to view the information, forward it to > others or tamper with the information without the knowledge or consent > of the sender. If you are not the intended recipient, or the employee > or person responsible for delivering the message to the intended > recipient, any dissemination, distribution or copying of the > communication is strictly prohibited. If you received the > communication in error, please notify the sender immediately by > replying to this message and deleting the message and any accompanying > files from your system. If, due to the security risks, you do not wish > to receive further communications via e-mail, please reply to this message and inform the sender that you do not wish to receive further e-mail from the sender. > (LCP301) > ------------------------------------------------------------ > |
|
|
Christian Wilms |
Re: Safe to run multiphoton laser at 100% power for overnight continuous imaging?
|
|
In reply to this post by Moulding, Dale
*****
To join, leave or search the confocal microscopy listserv, go to: http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy Post images on http://www.imgur.com and include the link in your posting. ***** Hi Dale, Even before the microscope there can be substantial power loss. I am not familiar with the table optics used in your system, but assuming you have a bunch of mirrors, a Pockels cell, and potentially a beam expander, you would be surprised how 'little' of those 3 W actually get into the microscope. The same is then true in the microscope as well: depending on the optics you will see a further drop off. In line with what Craig said, I would suggest you measure the power at the sample plane, as well as the power going into the actual microscope scanhead (if you can access that point). This will give you an idea of what you are actually dealing with. In over 15 years working with multiphoton systems (both in the lab and working for a microscopy company), I have not seen an objective 'burn out'. Pockels cells have upper limits, but the system should have been set up from the start to attenuate the beam prior to the Pockels, if the direct laser output is above that threshold. In general, Pockels cells can deteriorate over time, as Brian mentions, but that will heavily depend on how well the Pockels cell is aligned. Regarding your actual question: If you want a statement that you can rely on (including in terms of warrantee) I would strongly recommend asking your Zeiss representative. Cheers, Christian Dr. Christian Wilms / Research & Development Manager [hidden email] / +44 (0)1825 749933 www.scientifica.uk.com > -----Original Message----- > From: Craig Brideau <[hidden email]> > Sent: 25 September 2018 17:13 > Subject: Re: Safe to run multiphoton laser at 100% power for overnight > continuous imaging? > > ***** > To join, leave or search the confocal microscopy listserv, go to: > http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy > Post images on http://www.imgur.com and include the link in your posting. > ***** > > You do raise a valid point Brian, the power of most Ti:Saphs varies fairly > dramatically by wavelength. The transmission through the optical system will > also be different, and what the system considers '100%' may not actually be > that much power under certain situations. In most cases, however, a Ti:Saph > can produce much more power than is necessary for imaging. > Try measuring the power out of the objective when set to 100% to see what > you are actually getting; maybe it isn't that much compared to the output of > the laser once all the system losses are considered. > > Craig > > On Tue, Sep 25, 2018 at 9:41 AM Armstrong, Brian <[hidden email]> > wrote: > > > ***** > > To join, leave or search the confocal microscopy listserv, go to: > > http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy > > Post images on http://www.imgur.com and include the link in your posting. > > ***** > > > > Hi Dale, it depends in part on the wavelength. As I imagine you > > already know the output power at say 1050nm is far lower than say > > 800nm. I do not think the LASER "cares" what your output power is. As > > for the optics I cannot say. I think that they fall off in > > transmittance above a given wavelength in the IR range but I do not > > know if this is because of a coating or properties of the lens??? I > > have heard stories of people burning objectives. Pockels cells will also burn > out after around 10 years or so. > > > > P.S. How do you like the 10x/0.5 W for 2P work? > > > > Brian Armstrong PhD > > Associate Research Professor > > Developmental and Stem Cell Biology > > Diabetes and Metabolic Diseases > > Director, Light Microscopy Core > > Beckman Research Institute, City of Hope > > > > > > > > -----Original Message----- > > From: Confocal Microscopy List > > [mailto:[hidden email]] > > On Behalf Of Moulding, Dale > > Sent: Tuesday, September 25, 2018 5:56 AM > > To: [hidden email] > > Subject: Safe to run multiphoton laser at 100% power for overnight > > continuous imaging? > > > > [Attention: This email came from an external source. Do not open > > attachments or click on links from unknown senders or unexpected > > emails.] > > > > > > > > > > > > ***** > > To join, leave or search the confocal microscopy listserv, go to: > > http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy > > Post images on http://www.imgur.com and include the link in your posting. > > ***** > > > > Dear list, > > > > I've been asked to run our 2 photon laser (Mai Tai eHP DeepSee) at > > full power (3W) non-stop over night to scan a large sample. > > When doing ablations we run at 100% and I hadn't even given it a > > second thought, as the ablations are over in a flash. > > However, continuously (4 to 16 hours) running 100% 800nM at 3W I'm > > concerned we may damage the optics of the system. It will be on a > > Zeiss Examiner, going through Zeiss's 10x0.5 or 20x1.0 water dippers. > > Has anyone ever imaged / ablated with a 2P laser continuously at full > > power? > > Should I be concerned that the objectives may be damaged? > > > > Cheers > > > > Dale > > > > > > Dale Moulding PhD FRMS > > ICH Light Microscopy Facility > > Room W2.06, BDRC office > > UCL Great Ormond Street Institute of Child Health > > 30 Guilford St > > London WC1N 1EH > > Mob: 07787 699609 > > Tel: 020 7905 2753 > > > > http://www.ucl.ac.uk/ich/core-scientific-facilities-centres/confocal-m > > icroscopy > > > > ------------------------------------------------------------ > > -SECURITY/CONFIDENTIALITY WARNING- > > > > This message and any attachments are intended solely for the > > individual or entity to which they are addressed. This communication > > may contain information that is privileged, confidential, or exempt > > from disclosure under applicable law (e.g., personal health > > information, research data, financial information). Because this > > e-mail has been sent without encryption, individuals other than the > > intended recipient may be able to view the information, forward it to > > others or tamper with the information without the knowledge or consent > > of the sender. If you are not the intended recipient, or the employee > > or person responsible for delivering the message to the intended > > recipient, any dissemination, distribution or copying of the > > communication is strictly prohibited. If you received the > > communication in error, please notify the sender immediately by > > replying to this message and deleting the message and any accompanying > > files from your system. If, due to the security risks, you do not wish > > to receive further communications via e-mail, please reply to this message > and inform the sender that you do not wish to receive further e-mail from > the sender. > > (LCP301) > > ------------------------------------------------------------ > > |
|
|
Steffen Dietzel |
Re: Safe to run multiphoton laser at 100% power for overnight continuous imaging?
|
|
*****
To join, leave or search the confocal microscopy listserv, go to: http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy Post images on http://www.imgur.com and include the link in your posting. ***** Am 26.09.2018 um 11:00 schrieb Christian Wilms: > In line with what Craig said, I would suggest you measure the power at the sample plane, as well as the power going into the actual microscope scanhead (if you can access that point). This will give you an idea of what you are actually dealing with. But (as far as I know) the usual power meters only give an accurate reading with light that falls orthogonally on their surface. So with a high NA objective, at the sample plane the measured value would be substantially less than the actual power and you only get a 'minimal estimate'. Some people use a 10x therefore, which has a low NA. Or you can measure without objective to get a maximum estimate, disregarding the less-than-100%-transmission of the objective (and the cut-off that does not enter the objective). The true value then should be between the two estimates. Apparently it is virtually impossible to do this measurement at the sample plane accurately with the usual tools. Steffen -- ------------------------------------------------------------ Steffen Dietzel, PD Dr. rer. nat Ludwig-Maximilians-Universität München Biomedical Center (BMC) Head of the Core Facility Bioimaging Großhaderner Straße 9 D-82152 Planegg-Martinsried Germany http://www.bioimaging.bmc.med.uni-muenchen.de |
|
|
Armstrong, Brian |
Re: Safe to run multiphoton laser at 100% power for overnight continuous imaging?
|
|
In reply to this post by Moulding, Dale
*****
To join, leave or search the confocal microscopy listserv, go to: http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy Post images on http://www.imgur.com and include the link in your posting. ***** Dale, thank you for the answers. Can you please update this post when you complete the experiment? Especially if you damage the lens. Thanks in advance, Brian Armstrong PhD Associate Research Professor Developmental and Stem Cell Biology Diabetes and Metabolic Diseases Director, Light Microscopy Core Beckman Research Institute, City of Hope -----Original Message----- From: Confocal Microscopy List [mailto:[hidden email]] On Behalf Of Moulding, Dale Sent: Wednesday, September 26, 2018 2:00 AM To: [hidden email] Subject: Re: Safe to run multiphoton laser at 100% power for overnight continuous imaging? ***** To join, leave or search the confocal microscopy listserv, go to: http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy Post images on http://www.imgur.com and include the link in your posting. ***** Dear all, Thanks for the replies. It will be at 800nM, so full power output, and will be continuously firing though the objective for at least 4 hours as it is not for imaging but for catalysis. Zeiss aren't able to guarantee their objectives for this (drilling to the centre of the earth!), so if I do get a cracked lens / glue then I'm not sure our service contract will cover it. @Lorenzo, for your 16 hour experiment were you sending the laser through the objective non-stop for the entire time, or just imaging periodically? @Craig, agreed, it’s a lot of power, but not for imaging, for catalysis. @Brian, I love the 10x0.5 dipper for 2P work. Massive improvement over the 10x0.3. @Claire, I'm not sure Zeiss will cover the damage this time, and haven't really had a definitive answer, unless I've misunderstood them. Cheers Dale -----Original Message----- From: Confocal Microscopy List <[hidden email]> On Behalf Of Craig Brideau Sent: 25 September 2018 17:13 To: [hidden email] Subject: Re: Safe to run multiphoton laser at 100% power for overnight continuous imaging? ***** To join, leave or search the confocal microscopy listserv, go to: http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy Post images on http://www.imgur.com and include the link in your posting. ***** You do raise a valid point Brian, the power of most Ti:Saphs varies fairly dramatically by wavelength. The transmission through the optical system will also be different, and what the system considers '100%' may not actually be that much power under certain situations. In most cases, however, a Ti:Saph can produce much more power than is necessary for imaging. Try measuring the power out of the objective when set to 100% to see what you are actually getting; maybe it isn't that much compared to the output of the laser once all the system losses are considered. Craig On Tue, Sep 25, 2018 at 9:41 AM Armstrong, Brian <[hidden email]> wrote: > ***** > To join, leave or search the confocal microscopy listserv, go to: > http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy > Post images on http://www.imgur.com and include the link in your posting. > ***** > > Hi Dale, it depends in part on the wavelength. As I imagine you > already know the output power at say 1050nm is far lower than say > 800nm. I do not think the LASER "cares" what your output power is. As > for the optics I cannot say. I think that they fall off in > transmittance above a given wavelength in the IR range but I do not > know if this is because of a coating or properties of the lens??? I > have heard stories of people burning objectives. Pockels cells will also burn out after around 10 years or so. > > P.S. How do you like the 10x/0.5 W for 2P work? > > Brian Armstrong PhD > Associate Research Professor > Developmental and Stem Cell Biology > Diabetes and Metabolic Diseases > Director, Light Microscopy Core > Beckman Research Institute, City of Hope > > > > -----Original Message----- > From: Confocal Microscopy List > [mailto:[hidden email]] > On Behalf Of Moulding, Dale > Sent: Tuesday, September 25, 2018 5:56 AM > To: [hidden email] > Subject: Safe to run multiphoton laser at 100% power for overnight > continuous imaging? > > [Attention: This email came from an external source. Do not open > attachments or click on links from unknown senders or unexpected > emails.] > > > > > > ***** > To join, leave or search the confocal microscopy listserv, go to: > http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy > Post images on http://www.imgur.com and include the link in your posting. > ***** > > Dear list, > > I've been asked to run our 2 photon laser (Mai Tai eHP DeepSee) at > full power (3W) non-stop over night to scan a large sample. > When doing ablations we run at 100% and I hadn't even given it a > second thought, as the ablations are over in a flash. > However, continuously (4 to 16 hours) running 100% 800nM at 3W I'm > concerned we may damage the optics of the system. It will be on a > Zeiss Examiner, going through Zeiss's 10x0.5 or 20x1.0 water dippers. > Has anyone ever imaged / ablated with a 2P laser continuously at full > power? > Should I be concerned that the objectives may be damaged? > > Cheers > > Dale > > > Dale Moulding PhD FRMS > ICH Light Microscopy Facility > Room W2.06, BDRC office > UCL Great Ormond Street Institute of Child Health > 30 Guilford St > London WC1N 1EH > Mob: 07787 699609 > Tel: 020 7905 2753 > > http://www.ucl.ac.uk/ich/core-scientific-facilities-centres/confocal-m > icroscopy > > ------------------------------------------------------------ > -SECURITY/CONFIDENTIALITY WARNING- > > This message and any attachments are intended solely for the > individual or entity to which they are addressed. This communication > may contain information that is privileged, confidential, or exempt > from disclosure under applicable law (e.g., personal health > information, research data, financial information). Because this > e-mail has been sent without encryption, individuals other than the > intended recipient may be able to view the information, forward it to > others or tamper with the information without the knowledge or consent > of the sender. If you are not the intended recipient, or the employee > or person responsible for delivering the message to the intended > recipient, any dissemination, distribution or copying of the > communication is strictly prohibited. If you received the > communication in error, please notify the sender immediately by > replying to this message and deleting the message and any accompanying > files from your system. If, due to the security risks, you do not wish > to receive further communications via e-mail, please reply to this message and inform the sender that you do not wish to receive further e-mail from the sender. > (LCP301) > ------------------------------------------------------------ > |
|
|
Moulding, Dale |
Re: Safe to run multiphoton laser at 100% power for overnight continuous imaging?
|
|
*****
To join, leave or search the confocal microscopy listserv, go to: http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy Post images on http://www.imgur.com and include the link in your posting. ***** Dear list, I've run the expt, decided to use a 10x0.3 as it's a lot cheaper than the dippers. We found we could get sufficient energy to the sample with a total of 3h30m continuous scanning. 2h at 700nm (1500mW), 1h30m at 800nm (3000mW). Good news, the objective didn't even get warm, no hint of damage. I destroyed my last power meter trying to measure the 2P laser (slightly exceeded it's limit!), but from memory with the Zeiss engineer meter only about 20% makes it to the sample. So 600mW perhaps. The objective has 90% transmission at 800nm. Cheers Dale Dale Moulding PhD FRMS ICH Light Microscopy Facility UCL Great Ormond Street Institute of Child Health 30 Guilford St London WC1N 1EH Mob: 07787 699609 Tel: 020 7905 2753 Please acknowledge use of the BRC funded facility in all publications: http://www.ucl.ac.uk/ich/core-scientific-facilities-centres/confocal-microscopy -------- Original message -------- From: "Armstrong, Brian" <[hidden email]> Date: 26/09/2018 16:26 (GMT+00:00) To: [hidden email] Subject: Re: Safe to run multiphoton laser at 100% power for overnight continuous imaging? ***** To join, leave or search the confocal microscopy listserv, go to: http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy Post images on http://www.imgur.com and include the link in your posting. ***** Dale, thank you for the answers. Can you please update this post when you complete the experiment? Especially if you damage the lens. Thanks in advance, Brian Armstrong PhD Associate Research Professor Developmental and Stem Cell Biology Diabetes and Metabolic Diseases Director, Light Microscopy Core Beckman Research Institute, City of Hope -----Original Message----- From: Confocal Microscopy List [mailto:[hidden email]] On Behalf Of Moulding, Dale Sent: Wednesday, September 26, 2018 2:00 AM To: [hidden email] Subject: Re: Safe to run multiphoton laser at 100% power for overnight continuous imaging? ***** To join, leave or search the confocal microscopy listserv, go to: http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy Post images on http://www.imgur.com and include the link in your posting. ***** Dear all, Thanks for the replies. It will be at 800nM, so full power output, and will be continuously firing though the objective for at least 4 hours as it is not for imaging but for catalysis. Zeiss aren't able to guarantee their objectives for this (drilling to the centre of the earth!), so if I do get a cracked lens / glue then I'm not sure our service contract will cover it. @Lorenzo, for your 16 hour experiment were you sending the laser through the objective non-stop for the entire time, or just imaging periodically? @Craig, agreed, it’s a lot of power, but not for imaging, for catalysis. @Brian, I love the 10x0.5 dipper for 2P work. Massive improvement over the 10x0.3. @Claire, I'm not sure Zeiss will cover the damage this time, and haven't really had a definitive answer, unless I've misunderstood them. Cheers Dale -----Original Message----- From: Confocal Microscopy List <[hidden email]> On Behalf Of Craig Brideau Sent: 25 September 2018 17:13 To: [hidden email] Subject: Re: Safe to run multiphoton laser at 100% power for overnight continuous imaging? ***** To join, leave or search the confocal microscopy listserv, go to: http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy Post images on http://www.imgur.com and include the link in your posting. ***** You do raise a valid point Brian, the power of most Ti:Saphs varies fairly dramatically by wavelength. The transmission through the optical system will also be different, and what the system considers '100%' may not actually be that much power under certain situations. In most cases, however, a Ti:Saph can produce much more power than is necessary for imaging. Try measuring the power out of the objective when set to 100% to see what you are actually getting; maybe it isn't that much compared to the output of the laser once all the system losses are considered. Craig On Tue, Sep 25, 2018 at 9:41 AM Armstrong, Brian <[hidden email]> wrote: > ***** > To join, leave or search the confocal microscopy listserv, go to: > http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy > Post images on http://www.imgur.com and include the link in your posting. > ***** > > Hi Dale, it depends in part on the wavelength. As I imagine you > already know the output power at say 1050nm is far lower than say > 800nm. I do not think the LASER "cares" what your output power is. As > for the optics I cannot say. I think that they fall off in > transmittance above a given wavelength in the IR range but I do not > know if this is because of a coating or properties of the lens??? I > have heard stories of people burning objectives. Pockels cells will also burn out after around 10 years or so. > > P.S. How do you like the 10x/0.5 W for 2P work? > > Brian Armstrong PhD > Associate Research Professor > Developmental and Stem Cell Biology > Diabetes and Metabolic Diseases > Director, Light Microscopy Core > Beckman Research Institute, City of Hope > > > > -----Original Message----- > From: Confocal Microscopy List > [mailto:[hidden email]] > On Behalf Of Moulding, Dale > Sent: Tuesday, September 25, 2018 5:56 AM > To: [hidden email] > Subject: Safe to run multiphoton laser at 100% power for overnight > continuous imaging? > > [Attention: This email came from an external source. Do not open > attachments or click on links from unknown senders or unexpected > emails.] > > > > > > ***** > To join, leave or search the confocal microscopy listserv, go to: > http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy > Post images on http://www.imgur.com and include the link in your posting. > ***** > > Dear list, > > I've been asked to run our 2 photon laser (Mai Tai eHP DeepSee) at > full power (3W) non-stop over night to scan a large sample. > When doing ablations we run at 100% and I hadn't even given it a > second thought, as the ablations are over in a flash. > However, continuously (4 to 16 hours) running 100% 800nM at 3W I'm > concerned we may damage the optics of the system. It will be on a > Zeiss Examiner, going through Zeiss's 10x0.5 or 20x1.0 water dippers. > Has anyone ever imaged / ablated with a 2P laser continuously at full > power? > Should I be concerned that the objectives may be damaged? > > Cheers > > Dale > > > Dale Moulding PhD FRMS > ICH Light Microscopy Facility > Room W2.06, BDRC office > UCL Great Ormond Street Institute of Child Health > 30 Guilford St > London WC1N 1EH > Mob: 07787 699609 > Tel: 020 7905 2753 > > http://www.ucl.ac.uk/ich/core-scientific-facilities-centres/confocal-m > icroscopy > > ------------------------------------------------------------ > -SECURITY/CONFIDENTIALITY WARNING- > > This message and any attachments are intended solely for the > individual or entity to which they are addressed. This communication > may contain information that is privileged, confidential, or exempt > from disclosure under applicable law (e.g., personal health > information, research data, financial information). Because this > e-mail has been sent without encryption, individuals other than the > intended recipient may be able to view the information, forward it to > others or tamper with the information without the knowledge or consent > of the sender. If you are not the intended recipient, or the employee > or person responsible for delivering the message to the intended > recipient, any dissemination, distribution or copying of the > communication is strictly prohibited. If you received the > communication in error, please notify the sender immediately by > replying to this message and deleting the message and any accompanying > files from your system. If, due to the security risks, you do not wish > to receive further communications via e-mail, please reply to this message and inform the sender that you do not wish to receive further e-mail from the sender. > (LCP301) > ------------------------------------------------------------ > |
|
|
Craig Brideau |
Re: Safe to run multiphoton laser at 100% power for overnight continuous imaging?
|
|
In reply to this post by Steffen Dietzel
*****
To join, leave or search the confocal microscopy listserv, go to: http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy Post images on http://www.imgur.com and include the link in your posting. ***** If you will allow me a shameless plug, I assisted Thorlabs with the design for a power meter for this specific purpose. I worked with the prototype and provided feedback alongside Dr. Pina Colarusso. There is an index matching gel under the surface which deals with the high NA rays, and you can use water or immersion oil safely on the sensor face: https://www.thorlabs.com/thorproduct.cfm?partnumber=S170C It is actually manufactured at one of their facilities in Germany. :) Craig On Wed, Sep 26, 2018 at 5:17 AM Steffen Dietzel <[hidden email]> wrote: > But (as far as I know) the usual power meters only give an accurate > reading with light that falls orthogonally on their surface. So with a > high NA objective, at the sample plane the measured value would be > substantially less than the actual power and you only get a 'minimal > estimate'. > Apparently it is virtually impossible to do this measurement at the > sample plane accurately with the usual tools. > > Steffen > > -- > ------------------------------------------------------------ > Steffen Dietzel, PD Dr. rer. nat > Ludwig-Maximilians-Universität München > Biomedical Center (BMC) > Head of the Core Facility Bioimaging > > Großhaderner Straße 9 > D-82152 Planegg-Martinsried > Germany > > http://www.bioimaging.bmc.med.uni-muenchen.de > |
|
|
Craig Brideau |
Re: Safe to run multiphoton laser at 100% power for overnight continuous imaging?
|
|
In reply to this post by Christian Wilms
*****
To join, leave or search the confocal microscopy listserv, go to: http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy Post images on http://www.imgur.com and include the link in your posting. ***** In one case I noted the back aperture of an objective was partly melted when the beam at high power overfilled the back aperture to an extreme degree. If the back aperture of the lens is large and the beam diameter is well matched then the majority of the power will go through the transparent glass. It is clipping at the edges of apertures that leads to absorption which can damage the lenses. It *is* possible for coatings on the lenses to go even with a well aimed beam, but this is much less likely with contemporary optical coatings. Craig On Wed, Sep 26, 2018 at 3:01 AM Christian Wilms < [hidden email]> wrote: > In over 15 years working with multiphoton systems (both in the lab and > working for a microscopy company), I have not seen an objective 'burn out'. > Pockels cells have upper limits, but the system should have been set up > from the start to attenuate the beam prior to the Pockels, if the direct > laser output is above that threshold. In general, Pockels cells can > deteriorate over time, as Brian mentions, but that will heavily depend on > how well the Pockels cell is aligned. > > Regarding your actual question: If you want a statement that you can rely > on (including in terms of warrantee) I would strongly recommend asking your > Zeiss representative. > > Cheers, Christian > > Dr. Christian Wilms / Research & Development Manager > [hidden email] / +44 (0)1825 749933 > www.scientifica.uk.com > > > -----Original Message----- > > From: Craig Brideau <[hidden email]> > > Sent: 25 September 2018 17:13 > > Subject: Re: Safe to run multiphoton laser at 100% power for overnight > > continuous imaging? > > > > ***** > > To join, leave or search the confocal microscopy listserv, go to: > > http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy > > Post images on http://www.imgur.com and include the link in your > posting. > > ***** > > > > You do raise a valid point Brian, the power of most Ti:Saphs varies > fairly > > dramatically by wavelength. The transmission through the optical system > will > > also be different, and what the system considers '100%' may not actually > be > > that much power under certain situations. In most cases, however, a > Ti:Saph > > can produce much more power than is necessary for imaging. > > Try measuring the power out of the objective when set to 100% to see what > > you are actually getting; maybe it isn't that much compared to the > output of > > the laser once all the system losses are considered. > > > > Craig > > > > On Tue, Sep 25, 2018 at 9:41 AM Armstrong, Brian <[hidden email]> > > wrote: > > > > > ***** > > > To join, leave or search the confocal microscopy listserv, go to: > > > http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy > > > Post images on http://www.imgur.com and include the link in your > posting. > > > ***** > > > > > > Hi Dale, it depends in part on the wavelength. As I imagine you > > > already know the output power at say 1050nm is far lower than say > > > 800nm. I do not think the LASER "cares" what your output power is. As > > > for the optics I cannot say. I think that they fall off in > > > transmittance above a given wavelength in the IR range but I do not > > > know if this is because of a coating or properties of the lens??? I > > > have heard stories of people burning objectives. Pockels cells will > also burn > > out after around 10 years or so. > > > > > > P.S. How do you like the 10x/0.5 W for 2P work? > > > > > > Brian Armstrong PhD > > > Associate Research Professor > > > Developmental and Stem Cell Biology > > > Diabetes and Metabolic Diseases > > > Director, Light Microscopy Core > > > Beckman Research Institute, City of Hope > > > > > > > > > > > > -----Original Message----- > > > From: Confocal Microscopy List > > > [mailto:[hidden email]] > > > On Behalf Of Moulding, Dale > > > Sent: Tuesday, September 25, 2018 5:56 AM > > > To: [hidden email] > > > Subject: Safe to run multiphoton laser at 100% power for overnight > > > continuous imaging? > > > > > > [Attention: This email came from an external source. Do not open > > > attachments or click on links from unknown senders or unexpected > > > emails.] > > > > > > > > > > > > > > > > > > ***** > > > To join, leave or search the confocal microscopy listserv, go to: > > > http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy > > > Post images on http://www.imgur.com and include the link in your > posting. > > > ***** > > > > > > Dear list, > > > > > > I've been asked to run our 2 photon laser (Mai Tai eHP DeepSee) at > > > full power (3W) non-stop over night to scan a large sample. > > > When doing ablations we run at 100% and I hadn't even given it a > > > second thought, as the ablations are over in a flash. > > > However, continuously (4 to 16 hours) running 100% 800nM at 3W I'm > > > concerned we may damage the optics of the system. It will be on a > > > Zeiss Examiner, going through Zeiss's 10x0.5 or 20x1.0 water dippers. > > > Has anyone ever imaged / ablated with a 2P laser continuously at full > > > power? > > > Should I be concerned that the objectives may be damaged? > > > > > > Cheers > > > > > > Dale > > > > > > > > > Dale Moulding PhD FRMS > > > ICH Light Microscopy Facility > > > Room W2.06, BDRC office > > > UCL Great Ormond Street Institute of Child Health > > > 30 Guilford St > > > London WC1N 1EH > > > Mob: 07787 699609 > > > Tel: 020 7905 2753 > > > > > > http://www.ucl.ac.uk/ich/core-scientific-facilities-centres/confocal-m > > > icroscopy > > > > > > ------------------------------------------------------------ > > > -SECURITY/CONFIDENTIALITY WARNING- > > > > > > This message and any attachments are intended solely for the > > > individual or entity to which they are addressed. This communication > > > may contain information that is privileged, confidential, or exempt > > > from disclosure under applicable law (e.g., personal health > > > information, research data, financial information). Because this > > > e-mail has been sent without encryption, individuals other than the > > > intended recipient may be able to view the information, forward it to > > > others or tamper with the information without the knowledge or consent > > > of the sender. If you are not the intended recipient, or the employee > > > or person responsible for delivering the message to the intended > > > recipient, any dissemination, distribution or copying of the > > > communication is strictly prohibited. If you received the > > > communication in error, please notify the sender immediately by > > > replying to this message and deleting the message and any accompanying > > > files from your system. If, due to the security risks, you do not wish > > > to receive further communications via e-mail, please reply to this > message > > and inform the sender that you do not wish to receive further e-mail from > > the sender. > > > (LCP301) > > > ------------------------------------------------------------ > > > > |
|
|
Dr. K N Ganesh |
Re: Safe to run multiphoton laser at 100% power for overnight continuous imaging?
|
|
In reply to this post by Moulding, Dale
*****
To join, leave or search the confocal microscopy listserv, go to: http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy Post images on http://www.imgur.com and include the link in your posting. ***** Hi All In one of our imaging conditions with 10x dey objectives on live mouse we observed vapour condensation.. Thus making the image hazy .. Sent from my iPhone > On 26-Sep-2018, at 10:39 PM, Moulding, Dale <[hidden email]> wrote: > > ***** > To join, leave or search the confocal microscopy listserv, go to: > http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy > Post images on http://www.imgur.com and include the link in your posting. > ***** > > Dear list, > > I've run the expt, decided to use a 10x0.3 as it's a lot cheaper than the dippers. We found we could get sufficient energy to the sample with a total of 3h30m continuous scanning. 2h at 700nm (1500mW), 1h30m at 800nm (3000mW). > Good news, the objective didn't even get warm, no hint of damage. > I destroyed my last power meter trying to measure the 2P laser (slightly exceeded it's limit!), but from memory with the Zeiss engineer meter only about 20% makes it to the sample. So 600mW perhaps. The objective has 90% transmission at 800nm. > > Cheers > > Dale > > > > > > Dale Moulding PhD FRMS > ICH Light Microscopy Facility > UCL Great Ormond Street Institute of Child Health > 30 Guilford St > London WC1N 1EH > Mob: 07787 699609 > Tel: 020 7905 2753 > > Please acknowledge use of the BRC funded facility in all publications: > http://www.ucl.ac.uk/ich/core-scientific-facilities-centres/confocal-microscopy > > > -------- Original message -------- > From: "Armstrong, Brian" <[hidden email]> > Date: 26/09/2018 16:26 (GMT+00:00) > To: [hidden email] > Subject: Re: Safe to run multiphoton laser at 100% power for overnight continuous imaging? > > ***** > To join, leave or search the confocal microscopy listserv, go to: > http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy > Post images on http://www.imgur.com and include the link in your posting. > ***** > > Dale, thank you for the answers. Can you please update this post when you complete the experiment? Especially if you damage the lens. > Thanks in advance, > > Brian Armstrong PhD > Associate Research Professor > Developmental and Stem Cell Biology > Diabetes and Metabolic Diseases > Director, Light Microscopy Core > Beckman Research Institute, City of Hope > > > > -----Original Message----- > From: Confocal Microscopy List [mailto:[hidden email]] On Behalf Of Moulding, Dale > Sent: Wednesday, September 26, 2018 2:00 AM > To: [hidden email] > Subject: Re: Safe to run multiphoton laser at 100% power for overnight continuous imaging? > > ***** > To join, leave or search the confocal microscopy listserv, go to: > http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy > Post images on http://www.imgur.com and include the link in your posting. > ***** > > Dear all, > > Thanks for the replies. It will be at 800nM, so full power output, and will be continuously firing though the objective for at least 4 hours as it is not for imaging but for catalysis. > Zeiss aren't able to guarantee their objectives for this (drilling to the centre of the earth!), so if I do get a cracked lens / glue then I'm not sure our service contract will cover it. > > @Lorenzo, for your 16 hour experiment were you sending the laser through the objective non-stop for the entire time, or just imaging periodically? > @Craig, agreed, it’s a lot of power, but not for imaging, for catalysis. > @Brian, I love the 10x0.5 dipper for 2P work. Massive improvement over the 10x0.3. > @Claire, I'm not sure Zeiss will cover the damage this time, and haven't really had a definitive answer, unless I've misunderstood them. > > Cheers > > Dale > > -----Original Message----- > From: Confocal Microscopy List <[hidden email]> On Behalf Of Craig Brideau > Sent: 25 September 2018 17:13 > To: [hidden email] > Subject: Re: Safe to run multiphoton laser at 100% power for overnight continuous imaging? > > ***** > To join, leave or search the confocal microscopy listserv, go to: > http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy > Post images on http://www.imgur.com and include the link in your posting. > ***** > > You do raise a valid point Brian, the power of most Ti:Saphs varies fairly dramatically by wavelength. The transmission through the optical system will also be different, and what the system considers '100%' may not actually be that much power under certain situations. In most cases, however, a Ti:Saph can produce much more power than is necessary for imaging. > Try measuring the power out of the objective when set to 100% to see what you are actually getting; maybe it isn't that much compared to the output of the laser once all the system losses are considered. > > Craig > >> On Tue, Sep 25, 2018 at 9:41 AM Armstrong, Brian <[hidden email]> wrote: >> >> ***** >> To join, leave or search the confocal microscopy listserv, go to: >> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy >> Post images on http://www.imgur.com and include the link in your posting. >> ***** >> >> Hi Dale, it depends in part on the wavelength. As I imagine you >> already know the output power at say 1050nm is far lower than say >> 800nm. I do not think the LASER "cares" what your output power is. As >> for the optics I cannot say. I think that they fall off in >> transmittance above a given wavelength in the IR range but I do not >> know if this is because of a coating or properties of the lens??? I >> have heard stories of people burning objectives. Pockels cells will also burn out after around 10 years or so. >> >> P.S. How do you like the 10x/0.5 W for 2P work? >> >> Brian Armstrong PhD >> Associate Research Professor >> Developmental and Stem Cell Biology >> Diabetes and Metabolic Diseases >> Director, Light Microscopy Core >> Beckman Research Institute, City of Hope >> >> >> >> -----Original Message----- >> From: Confocal Microscopy List >> [mailto:[hidden email]] >> On Behalf Of Moulding, Dale >> Sent: Tuesday, September 25, 2018 5:56 AM >> To: [hidden email] >> Subject: Safe to run multiphoton laser at 100% power for overnight >> continuous imaging? >> >> [Attention: This email came from an external source. Do not open >> attachments or click on links from unknown senders or unexpected >> emails.] >> >> >> >> >> >> ***** >> To join, leave or search the confocal microscopy listserv, go to: >> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy >> Post images on http://www.imgur.com and include the link in your posting. >> ***** >> >> Dear list, >> >> I've been asked to run our 2 photon laser (Mai Tai eHP DeepSee) at >> full power (3W) non-stop over night to scan a large sample. >> When doing ablations we run at 100% and I hadn't even given it a >> second thought, as the ablations are over in a flash. >> However, continuously (4 to 16 hours) running 100% 800nM at 3W I'm >> concerned we may damage the optics of the system. It will be on a >> Zeiss Examiner, going through Zeiss's 10x0.5 or 20x1.0 water dippers. >> Has anyone ever imaged / ablated with a 2P laser continuously at full >> power? >> Should I be concerned that the objectives may be damaged? >> >> Cheers >> >> Dale >> >> >> Dale Moulding PhD FRMS >> ICH Light Microscopy Facility >> Room W2.06, BDRC office >> UCL Great Ormond Street Institute of Child Health >> 30 Guilford St >> London WC1N 1EH >> Mob: 07787 699609 >> Tel: 020 7905 2753 >> >> http://www.ucl.ac.uk/ich/core-scientific-facilities-centres/confocal-m >> icroscopy >> >> ------------------------------------------------------------ >> -SECURITY/CONFIDENTIALITY WARNING- >> >> This message and any attachments are intended solely for the >> individual or entity to which they are addressed. This communication >> may contain information that is privileged, confidential, or exempt >> from disclosure under applicable law (e.g., personal health >> information, research data, financial information). Because this >> e-mail has been sent without encryption, individuals other than the >> intended recipient may be able to view the information, forward it to >> others or tamper with the information without the knowledge or consent >> of the sender. If you are not the intended recipient, or the employee >> or person responsible for delivering the message to the intended >> recipient, any dissemination, distribution or copying of the >> communication is strictly prohibited. If you received the >> communication in error, please notify the sender immediately by >> replying to this message and deleting the message and any accompanying >> files from your system. If, due to the security risks, you do not wish >> to receive further communications via e-mail, please reply to this message and inform the sender that you do not wish to receive further e-mail from the sender. >> (LCP301) >> ------------------------------------------------------------ >> |
|
|
Moulding, Dale |
Re: Safe to run multiphoton laser at 100% power for overnight continuous imaging?
|
|
In reply to this post by Craig Brideau
*****
To join, leave or search the confocal microscopy listserv, go to: http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy Post images on http://www.imgur.com and include the link in your posting. ***** Hi Craig, that is the exact model of power meter I destroyed trying to measure 2P laser power. I was new to the job and had no idea the power meter had limits. I measured visible lasers and got expected results. Measured 2P laser and each time I repeated the measure the value decreased, a lot! Asked thorlabs, and they explained I’d somewhat exceeded the power capacity as peak power was 100s of kW and average power >2W. Considerably more than the 150 mW limit. I asked if the 175C thermal meter (2W max) would be ok but Thorlabs didn’t recommend it. I no longer measure the 2P laser power directly, but do periodic comparisons of chroma slide brightness to check powers are as expected. Any recommendations for an economical 2P suitable meter? Cheers Dale Dale Moulding PhD FRMS ICH Light Microscopy Facility UCL Great Ormond Street lnstitute of Child Health 30 Guilford Street London WC1N 1EH Mob: 07787 699 609 Tel: 020 7905 2753 Please acknowledge use of the BRC funded facility in all publications: http://www.ucl.ac.uk/ich/core-scientific-facilities-centres/confocal-microscopy ________________________________ From: Confocal Microscopy List <[hidden email]> on behalf of Craig Brideau <[hidden email]> Sent: 26 September 2018 18:18:04 To: [hidden email] Subject: Re: Safe to run multiphoton laser at 100% power for overnight continuous imaging? ***** To join, leave or search the confocal microscopy listserv, go to: http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy Post images on http://www.imgur.com and include the link in your posting. ***** If you will allow me a shameless plug, I assisted Thorlabs with the design for a power meter for this specific purpose. I worked with the prototype and provided feedback alongside Dr. Pina Colarusso. There is an index matching gel under the surface which deals with the high NA rays, and you can use water or immersion oil safely on the sensor face: https://www.thorlabs.com/thorproduct.cfm?partnumber=S170C It is actually manufactured at one of their facilities in Germany. :) Craig On Wed, Sep 26, 2018 at 5:17 AM Steffen Dietzel <[hidden email]> wrote: > But (as far as I know) the usual power meters only give an accurate > reading with light that falls orthogonally on their surface. So with a > high NA objective, at the sample plane the measured value would be > substantially less than the actual power and you only get a 'minimal > estimate'. > Apparently it is virtually impossible to do this measurement at the > sample plane accurately with the usual tools. > > Steffen > > -- > ------------------------------------------------------------ > Steffen Dietzel, PD Dr. rer. nat > Ludwig-Maximilians-Universität München > Biomedical Center (BMC) > Head of the Core Facility Bioimaging > > Großhaderner Straße 9 > D-82152 Planegg-Martinsried > Germany > > http://www.bioimaging.bmc.med.uni-muenchen.de > |
|
|
Christian Wilms |
Re: Safe to run multiphoton laser at 100% power for overnight continuous imaging?
|
|
In reply to this post by Moulding, Dale
*****
To join, leave or search the confocal microscopy listserv, go to: http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy Post images on http://www.imgur.com and include the link in your posting. ***** Hi Steffen, Your point is taken. This will depend on the type of detector head used. When dealing with ultrafast lasers, I have moved towards using thermal sensors where possible. While they are noisy and slow, they are not prone to non-linearities when using ultrafast pulsed lasers. My understanding of theses thermal sensors is that they are overly not sensitive to angel of incidence, either. Cheers, Christian Dr. Christian Wilms / Research & Development Manager [hidden email] / +44 (0)1825 749933 www.scientifica.uk.com > -----Original Message----- > From: Steffen Dietzel <[hidden email]> > Sent: 26 September 2018 12:17 > Subject: Re: Safe to run multiphoton laser at 100% power for overnight > continuous imaging? > > ***** > To join, leave or search the confocal microscopy listserv, go to: > http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy > Post images on http://www.imgur.com and include the link in your posting. > ***** > > Am 26.09.2018 um 11:00 schrieb Christian Wilms: > > In line with what Craig said, I would suggest you measure the power at the > sample plane, as well as the power going into the actual microscope > scanhead (if you can access that point). This will give you an idea of what you > are actually dealing with. > But (as far as I know) the usual power meters only give an accurate reading > with light that falls orthogonally on their surface. So with a high NA objective, > at the sample plane the measured value would be substantially less than the > actual power and you only get a 'minimal estimate'. Some people use a 10x > therefore, which has a low NA. Or you can measure without objective to get > a maximum estimate, disregarding the less-than-100%-transmission of the > objective (and the cut-off that does not enter the objective). The true value > then should be between the two estimates. > > Apparently it is virtually impossible to do this measurement at the sample > plane accurately with the usual tools. > > Steffen > > -- > ------------------------------------------------------------ > Steffen Dietzel, PD Dr. rer. nat > Ludwig-Maximilians-Universität München > Biomedical Center (BMC) > Head of the Core Facility Bioimaging > > Großhaderner Straße 9 > D-82152 Planegg-Martinsried > Germany > > http://www.bioimaging.bmc.med.uni-muenchen.de |
|
|
Zdenek Svindrych-2 |
Re: Safe to run multiphoton laser at 100% power for overnight continuous imaging?
|
|
In reply to this post by Moulding, Dale
*****
To join, leave or search the confocal microscopy listserv, go to: http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy Post images on http://www.imgur.com and include the link in your posting. ***** Hi Dale, I've always used thermopile sensor for the Watt range powers, and photodiode -based sensors for lower powers. Most were Coherent, so not exactly 'economical'. But the power is just half of the story, you need short pulses too! What I found very useful is checking the laser spectrum with a spectrometer (it's a must for manually tuned lasers like Mira 900). The spectrum will tell you whether the laser is modelocked properly. Some lasers (e.g. Coherent Chameleon Ultra) have built-in spectrometer, it's good idea to look at the spectrum from time to time (*before* things go wrong). You can even use it as a rough estimate of relative power change over time. Best, zdenek -- Zdenek Svindrych, Ph.D. Research Associate - Imaging Specialist Department of Biochemistry and Cell Biology Geisel School of Medicine at Dartmouth email: [hidden email] ---------- Původní e-mail ---------- Od: Moulding, Dale <[hidden email]> Komu: [hidden email] Datum: 27. 9. 2018 4:58:58 Předmět: Re: Safe to run multiphoton laser at 100% power for overnight continuous imaging? "***** To join, leave or search the confocal microscopy listserv, go to: http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy Post images on http://www.imgur.com and include the link in your posting. ***** Hi Craig, that is the exact model of power meter I destroyed trying to measure 2P laser power. I was new to the job and had no idea the power meter had limits. I measured visible lasers and got expected results. Measured 2P laser and each time I repeated the measure the value decreased, a lot! Asked thorlabs, and they explained I’d somewhat exceeded the power capacity as peak power was 100s of kW and average power >2W. Considerably more than the 150 mW limit. I asked if the 175C thermal meter (2W max) would be ok but Thorlabs didn’t recommend it. I no longer measure the 2P laser power directly, but do periodic comparisons of chroma slide brightness to check powers are as expected. Any recommendations for an economical 2P suitable meter? Cheers Dale Dale Moulding PhD FRMS ICH Light Microscopy Facility UCL Great Ormond Street lnstitute of Child Health 30 Guilford Street London WC1N 1EH Mob: 07787 699 609 Tel: 020 7905 2753 Please acknowledge use of the BRC funded facility in all publications: http://www.ucl.ac.uk/ich/core-scientific-facilities-centres/confocal- microscopy ________________________________ From: Confocal Microscopy List <[hidden email]> on behalf of Craig Brideau <[hidden email]> Sent: 26 September 2018 18:18:04 To: [hidden email] Subject: Re: Safe to run multiphoton laser at 100% power for overnight continuous imaging? ***** To join, leave or search the confocal microscopy listserv, go to: http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy Post images on http://www.imgur.com and include the link in your posting. ***** If you will allow me a shameless plug, I assisted Thorlabs with the design for a power meter for this specific purpose. I worked with the prototype and provided feedback alongside Dr. Pina Colarusso. There is an index matching gel under the surface which deals with the high NA rays, and you can use water or immersion oil safely on the sensor face: https://www.thorlabs.com/thorproduct.cfm?partnumber=S170C It is actually manufactured at one of their facilities in Germany. :) Craig On Wed, Sep 26, 2018 at 5:17 AM Steffen Dietzel <[hidden email]> wrote: > But (as far as I know) the usual power meters only give an accurate > reading with light that falls orthogonally on their surface. So with a > high NA objective, at the sample plane the measured value would be > substantially less than the actual power and you only get a 'minimal > estimate'. > Apparently it is virtually impossible to do this measurement at the > sample plane accurately with the usual tools. > > Steffen > > -- > ------------------------------------------------------------ > Steffen Dietzel, PD Dr. rer. nat > Ludwig-Maximilians-Universität München > Biomedical Center (BMC) > Head of the Core Facility Bioimaging > > Großhaderner Straße 9 > D-82152 Planegg-Martinsried > Germany > > http://www.bioimaging.bmc.med.uni-muenchen.de > |
|
|
Craig Brideau |
Re: Safe to run multiphoton laser at 100% power for overnight continuous imaging?
|
|
In reply to this post by Moulding, Dale
*****
To join, leave or search the confocal microscopy listserv, go to: http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy Post images on http://www.imgur.com and include the link in your posting. ***** Hi Dale, the S405C can handle up to 5W, and is fairly small for a thermopile, so it might work for you. It's about the size of a Thorlabs cage plate so it is possible to cram it onto a microscope stage. Since it is a thermopile instead of a silicon sensor it also doesn't care about NA of the incident light, as long as all light hits within the detector area. It has a 10mm detector, so it's not too difficult to achieve this. Note the *minimum* power of this sensor is 100uW, so you want to be measuring at least mW level power for this sensor to be of use. https://www.thorlabs.com/newgrouppage9.cfm?objectgroup_id=3333 I hope this helps! Craig On Thu, Sep 27, 2018 at 2:56 AM Moulding, Dale <[hidden email]> wrote: > ***** > To join, leave or search the confocal microscopy listserv, go to: > http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy > Post images on http://www.imgur.com and include the link in your posting. > ***** > > Hi Craig, > > that is the exact model of power meter I destroyed trying to measure 2P > laser power. I was new to the job and had no idea the power meter had > limits. I measured visible lasers and got expected results. Measured 2P > laser and each time I repeated the measure the value decreased, a lot! > Asked thorlabs, and they explained I’d somewhat exceeded the power > capacity as peak power was 100s of kW and average power >2W. Considerably > more than the 150 mW limit. I asked if the 175C thermal meter (2W max) > would be ok but Thorlabs didn’t recommend it. > I no longer measure the 2P laser power directly, but do periodic > comparisons of chroma slide brightness to check powers are as expected. > > Any recommendations for an economical 2P suitable meter? > > Cheers > > Dale > > Dale Moulding PhD FRMS > ICH Light Microscopy Facility > UCL Great Ormond Street lnstitute of Child Health > 30 Guilford Street > London WC1N 1EH > Mob: 07787 699 609 > Tel: 020 7905 2753 > Please acknowledge use of the BRC funded facility in all publications: > > http://www.ucl.ac.uk/ich/core-scientific-facilities-centres/confocal-microscopy > > ________________________________ > From: Confocal Microscopy List <[hidden email]> on > behalf of Craig Brideau <[hidden email]> > Sent: 26 September 2018 18:18:04 > To: [hidden email] > Subject: Re: Safe to run multiphoton laser at 100% power for overnight > continuous imaging? > > ***** > To join, leave or search the confocal microscopy listserv, go to: > http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy > Post images on http://www.imgur.com and include the link in your posting. > ***** > > If you will allow me a shameless plug, I assisted Thorlabs with the design > for a power meter for this specific purpose. I worked with the prototype > and provided feedback alongside Dr. Pina Colarusso. There is an index > matching gel under the surface which deals with the high NA rays, and you > can use water or immersion oil safely on the sensor face: > > https://www.thorlabs.com/thorproduct.cfm?partnumber=S170C > > It is actually manufactured at one of their facilities in Germany. :) > > Craig > > > > On Wed, Sep 26, 2018 at 5:17 AM Steffen Dietzel <[hidden email]> > wrote: > > > But (as far as I know) the usual power meters only give an accurate > > reading with light that falls orthogonally on their surface. So with a > > high NA objective, at the sample plane the measured value would be > > substantially less than the actual power and you only get a 'minimal > > estimate'. > > Apparently it is virtually impossible to do this measurement at the > > sample plane accurately with the usual tools. > > > > Steffen > > > > -- > > ------------------------------------------------------------ > > Steffen Dietzel, PD Dr. rer. nat > > Ludwig-Maximilians-Universität München > > Biomedical Center (BMC) > > Head of the Core Facility Bioimaging > > > > Großhaderner Straße 9 > > D-82152 Planegg-Martinsried > > Germany > > > > http://www.bioimaging.bmc.med.uni-muenchen.de > > > |
«
Return to Confocal Microscopy List
|
1 view|%1 views
| Free forum by Nabble | Edit this page |