pulse compression and MPE

[Watkins, Simon C]

folks, has anyone really noticed any real advantage from the pulse compression strategies offered by Spectraphysics or Coherent?  We have power to burn (literally!) in MPE sources nowadays, and while I recognize the theoretical advantages of prechirping, I wondered if it truly makes any practical difference in depth penetration into specimens.
Simon

Simon C. Watkins Ph.D, FRC Path
Professor and Vice Chair Cell Biology and Physiology
Professor Immunology
Director Center for Biologic Imaging
BSTS 225
University of Pittsburgh
3500 Terrace St
Pittsburgh PA 15261
412-352-2277
www.cbi.pitt.edu

[Moninger, Thomas]

I am also interested it this, especially in regards to the Zeiss 510
NLO. As has been discussed here recently this instrument has less then
ideal functionality in MP mode, likely due, I assume to their use of an
AOM instead of a Pockels cell. Has anyone on the list installed a
prechirper on such a system, or replaced the AOM with a Pockels cell?

Tom

Thomas Moninger [hidden email]
Assistant Director
University of Iowa Central Microscopy Research Facilities
www.uiowa.edu/~cemrf



Notice: This UI Health Care e-mail (including attachments) is covered by the Electronic Communications Privacy Act, 18 U.S.C. 2510-2521, is confidential and may be legally privileged.  If you are not the intended recipient, you are hereby notified that any retention, dissemination, distribution, or copying of this communication is strictly prohibited.  Please reply to the sender that you have received the message in error, then delete it.  Thank you.

-----Original Message-----
From: Confocal Microscopy List [mailto:[hidden email]]
On Behalf Of Watkins, Simon C
Sent: Friday, December 12, 2008 6:31 AM
To: [hidden email]
Subject: pulse compression and MPE

folks, has anyone really noticed any real advantage from the pulse
compression strategies offered by Spectraphysics or Coherent?  We have
power to burn (literally!) in MPE sources nowadays, and while I
recognize the theoretical advantages of prechirping, I wondered if it
truly makes any practical difference in depth penetration into
specimens.
Simon

Simon C. Watkins Ph.D, FRC Path
Professor and Vice Chair Cell Biology and Physiology
Professor Immunology
Director Center for Biologic Imaging
BSTS 225
University of Pittsburgh
3500 Terrace St
Pittsburgh PA 15261
412-352-2277
www.cbi.pitt.edu

[Moninger, Thomas]

Group,

I am also interested it this, especially in regards to the Zeiss 510
NLO. As was discussed here recently this instrument has less then
ideal functionality in MP mode, likely due I assume to their use of an
AOM instead of a Pockels cell. Has anyone on the list installed a
prechirper on such a system, or replaced the AOM with a Pockels cell?

Tom

Thomas Moninger [hidden email]
Assistant Director
University of Iowa Central Microscopy Research Facilities
www.uiowa.edu/~cemrf




Notice: This UI Health Care e-mail (including attachments) is covered by the Electronic Communications Privacy Act, 18 U.S.C. 2510-2521, is confidential and may be legally privileged.  If you are not the intended recipient, you are hereby notified that any retention, dissemination, distribution, or copying of this communication is strictly prohibited.  Please reply to the sender that you have received the message in error, then delete it.  Thank you.
-----Original Message-----
From: Confocal Microscopy List [mailto:[hidden email]]
On Behalf Of Watkins, Simon C
Sent: Friday, December 12, 2008 6:31 AM
To: [hidden email]
Subject: pulse compression and MPE

folks, has anyone really noticed any real advantage from the pulse
compression strategies offered by Spectraphysics or Coherent?  We have
power to burn (literally!) in MPE sources nowadays, and while I
recognize the theoretical advantages of prechirping, I wondered if it
truly makes any practical difference in depth penetration into
specimens.
Simon

Simon C. Watkins Ph.D, FRC Path
Professor and Vice Chair Cell Biology and Physiology
Professor Immunology
Director Center for Biologic Imaging
BSTS 225
University of Pittsburgh
3500 Terrace St
Pittsburgh PA 15261
412-352-2277
www.cbi.pitt.edu

[Craig Brideau]

Our multiphoton system has a large optical isolator in front of the laser that causes significant dispersion. I'm not sure how this compares to an AOM but I suspect the dispersion factors are in the same ballpark.  We have recently implemented a home-built prism compressor scheme and have found significant improvement in our multiphoton and SHG signal. I am currently finishing up a poster presentation for Photonics West which involves a small paper on the subject. I'll be happy to share it with any list members who contact me when I'm finished. I will post to the list when it is complete to let you know.

Craig

On Fri, Dec 12, 2008 at 12:54 PM, Moninger, Thomas <[hidden email]> wrote:

Group,

I am also interested it this, especially in regards to the Zeiss 510
NLO. As was discussed here recently this instrument has less then
ideal functionality in MP mode, likely due I assume to their use of an
AOM instead of a Pockels cell. Has anyone on the list installed a
prechirper on such a system, or replaced the AOM with a Pockels cell?

Tom

Thomas Moninger [hidden email]
Assistant Director
University of Iowa Central Microscopy Research Facilities
www.uiowa.edu/~cemrf




Notice: This UI Health Care e-mail (including attachments) is covered by the Electronic Communications Privacy Act, 18 U.S.C. 2510-2521, is confidential and may be legally privileged.  If you are not the intended recipient, you are hereby notified that any retention, dissemination, distribution, or copying of this communication is strictly prohibited.  Please reply to the sender that you have received the message in error, then delete it.  Thank you.
-----Original Message-----
From: Confocal Microscopy List [mailto:[hidden email]]
On Behalf Of Watkins, Simon C
Sent: Friday, December 12, 2008 6:31 AM
To: [hidden email]
Subject: pulse compression and MPE

folks, has anyone really noticed any real advantage from the pulse
compression strategies offered by Spectraphysics or Coherent?  We have
power to burn (literally!) in MPE sources nowadays, and while I
recognize the theoretical advantages of prechirping, I wondered if it
truly makes any practical difference in depth penetration into
specimens.
Simon

Simon C. Watkins Ph.D, FRC Path
Professor and Vice Chair Cell Biology and Physiology
Professor Immunology
Director Center for Biologic Imaging
BSTS 225
University of Pittsburgh
3500 Terrace St
Pittsburgh PA 15261
412-352-2277
www.cbi.pitt.edu

[Nick Durr]

Hello,
We haven't tried much experimentally, but there are a few nice theoretical
treatments of this that I've been looking through. Two papers I've found on
the subject that are pretty interesting:
Leray's "Spatially distributed two-photon excitation fluorescence in
scattering media: Experiments and time-resolved Monte Carlo simulations," and
Theer's "On the fundamental imaging-depth limit in two-photon microscopy"

If pulse energy isn't a limiting factor, your two-photon imaging depth most
likely limited by the creation of out-of-focus fluorescence, which degrades
your signal to noise. In this respect, decreasing your excitation pulse
length at large imaging depths can give you a slight increase in signal to
noise. For instance, going from 300fs to 50fs can decrease your out-of-focus
fluorescence generation relative to the in-focus fluorescence about about
50% when imaging at 5 mean free scattering path lengths deep, which will get
you very little increase in imaging depth (maybe an additional 0.2 MFPs).

There will be some benefits in being able to use less excitation energy to
generate the same amount of fluorescence (scales linearly with pulse
length), so you might have less bleaching or "burning", but for increasing
imaging depth, if you have enough pulse energy, I don't think shorter pulse
durations will help you much. Best,
-Nick Durr

[Craig Brideau]

Using a really high NA would also help, but this tends to cause working distance issues.

Craig

On Mon, Dec 15, 2008 at 10:44 AM, Nick Durr <[hidden email]> wrote:

Hello,
We haven't tried much experimentally, but there are a few nice theoretical
treatments of this that I've been looking through. Two papers I've found on
the subject that are pretty interesting:
Leray's "Spatially distributed two-photon excitation fluorescence in
scattering media: Experiments and time-resolved Monte Carlo simulations," and
Theer's "On the fundamental imaging-depth limit in two-photon microscopy"

If pulse energy isn't a limiting factor, your two-photon imaging depth most
likely limited by the creation of out-of-focus fluorescence, which degrades
your signal to noise. In this respect, decreasing your excitation pulse
length at large imaging depths can give you a slight increase in signal to
noise. For instance, going from 300fs to 50fs can decrease your out-of-focus
fluorescence generation relative to the in-focus fluorescence about about
50% when imaging at 5 mean free scattering path lengths deep, which will get
you very little increase in imaging depth (maybe an additional 0.2 MFPs).

There will be some benefits in being able to use less excitation energy to
generate the same amount of fluorescence (scales linearly with pulse
length), so you might have less bleaching or "burning", but for increasing
imaging depth, if you have enough pulse energy, I don't think shorter pulse
durations will help you much. Best,
-Nick Durr

[Craig Brideau]

Hey folks, I hope everyone had a good New Year's.  I've been saying for a few months now on the list that I'm working on a paper regarding pulse compression.  I've finally finished it and submitted it for the SPIE's Photonics West conference. If anyone wants a peek at the manuscript please give me a private email.

Craig Brideau
Hotchkiss Brain Institute
University of Calgary
Calgary, Canada

[Sherry Clendenon]

Hi,
I'd love a peek.
Thanks

>Hey folks, I hope everyone had a good New Year's.  I've been saying
>for a few months now on the list that I'm working on a paper
>regarding pulse compression.  I've finally finished it and submitted
>it for the SPIE's Photonics West conference. If anyone wants a peek
>at the manuscript please give me a private email.
>
>Craig Brideau
>Hotchkiss Brain Institute
>University of Calgary
>Calgary, Canada

--
Sherry G. Clendenon Ph.D
Indiana Center for Biological Microscopy
Indiana University Dept. of Medicine
Nephrology Division
950 W. Walnut St. R2-224
Indianapolis, In 46202

317-278-4668
[hidden email]

[Roberto Fernandez]

Hi,
It would be great if you could send me a peek.
Thank you very much !!!

--
Roberto Fernandez
IFIByNE (UBA-CONICET)
Buenos Aires, Argentina
email: [hidden email]

> Hey folks, I hope everyone had a good New Year's.  I've been saying for a
> few months now on the list that I'm working on a paper regarding pulse
> compression.  I've finally finished it and submitted it for the SPIE's
> Photonics West conference. If anyone wants a peek at the manuscript please
> give me a private email.
>
> Craig Brideau
> Hotchkiss Brain Institute
> University of Calgary
> Calgary, Canada
>