Re: Pulse compression and in vivo imaging

Posted by Craig Brideau on
URL: http://confocal-microscopy-list.275.s1.nabble.com/Pulse-compression-and-in-vivo-imaging-tp6557894p6564049.html

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Actually the Chameleon was designed for 140fs pulses for this reason.  For a
'typical' microscope system, transform-limited 140 fs gives you minimum
dispersion.  On the other hand, if you have a pulse compressor you want to
start with as short a pulse as possible as the compressor can keep
dispersion in check for you.
If I might ask, Stan, what do you use for a compressor on your 10fs laser?

Craig


On Fri, Jul 8, 2011 at 1:57 PM, Stanislav Vitha <[hidden email]> wrote:

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>
> Also, it depends on the pulse width.
> the shorter the pulse, the more you may need the dispersion control as you
> go
> deeper in the sample.
> On our system with 10 fs pulses, we really cannot live without pre-chirp
> (dispersion control). Your standard oscillator (~100-fs pulses?) is much
> more
> forgiving.
>
> Stan Vitha
> Microscopy and Imaging Center
> Texas A&M University
>
>
> On Thu, 7 Jul 2011 13:20:02 -0600, Craig Brideau
> <[hidden email]> wrote:
>
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> >If scattering is the issue then adaptive optics will be more advantageous
> >than dispersion control.  The adaptive optics will help compensate
> somewhat
> >for the scattering and aberrations induced by the tissue.  To get good 2P
> >imaging you need a good focal spot more-so than you need a perfectly
> >transform limited pulse.  Adaptive optics will help keep your focus
> together
> >as you try to image deeply.  That said, dispersion compensation will help
> >somewhat so if you already have the necessary equipment then try it.
> >
> >Craig
> >
> >
> >
> >On Thu, Jul 7, 2011 at 4:44 AM, Stéphane Pagès <
> >[hidden email]> wrote:
> >
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> >>
> >> Hi everybody,
> >> I am planning to image fluorescent neurons in vivo approximately  200 um
> >> below the pia with a standard Ti:Sa laser.
> >> I wonder if there is a clear advantage to use pulse compression to
> >> compensate for dispersion of pulses due to tissue.
> >> I understand theoretical arguments in favor of pulse compression.
> >> However from an experimental point of view, are there some people here
> in
> >> the list that have experienced some gain (in lowering the intensity of
> the
> >> exciting beam for example).
> >> Any comments would be greatly appreciated.
> >> Thanks a lot
> >> Stephane
> >>
>