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My thinking for Gary Brooker's widefield multiphoton is not to use it on
a spinning disk system, but rather on Andrew York & Hari Shroff's MSIM2
nanoscope - a much faster design than their 2012 Nature Methods paper
(keep an eye out for their work). Using it on Tom Jovin's PAM might also
be useful. If I have my math correct, a Chameleon Ultra II MP laser plus
Chameleon OPO-VIS on MSIM2 would also enable both WF-MPEF 2photon and
wide tuning range 1photon nanoscopy.
On 2/17/2013 3:14 PM, Craig Brideau wrote:
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> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
> *****
>
> I agree with George; it's just a matter of having enough power/energy to
> distribute amongst the beamlets on the disk. Unless there is an AOM in the
> system or the like compression probably wouldn't be much of an issue as
> well. Basically you can just brute-force it by using a lot of power into
> the scanning system. Given that current Ti:Saphs are overpowered for point
> scanning as it is, it should be feasible to get a sufficiently energetic
> system for spinning disk use.
>
> Craig
>
>
> On Sun, Feb 17, 2013 at 12:03 AM, Guy Cox<[log in to unmask]> wrote:
>
>
>> Hellwarth R and Christensen P. 1974, Nonlinear microscopic examination of
>> structure in polycrystalline ZnSe. Optics Communications 12, 318-322
>>
>> This was widefield SHG microscopy. If you can do that I guess you can do
>> widefield MPE as well. Frankly I can't see either as having any serious
>> practical application.
>>
>> Guy
>>
>> -----Original Message-----
>> From: Confocal Microscopy List [mailto:[log in to unmask]]
>> On Behalf Of George McNamara
>> Sent: Sunday, 17 February 2013 1:21 AM
>> To: [log in to unmask]
>> Subject: Re: multiphoton spinning disc
>>
>> *****
>> To join, leave or search the confocal microscopy listserv, go to:
>> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
>> *****
>>
>>
>> "multiphoton is ... not suitable for widefield."
>>
>> Gary Brooker and the US Patent Office disagree:
>>
>> http://www.google.com/patents/US7468837?
>>
>> *Patent number*: 7468837
>> *Filing date*: Dec 18, 2006
>> *Issue date*: Dec 23, 2008
>>
>> Wide-field multi-photon microscope having simultaneous confocal imaging
>> over at least two pixels.
>>
>>
>>
>>
>> On 2/16/2013 2:04 AM, Zdenek Svindrych wrote:
>>
>>> *****
>>> To join, leave or search the confocal microscopy listserv, go to:
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>>>
>>> Hi guys,
>>>
>>> it is a simple matter, multiphoton is not suitable for spinning disc as
>>>
>> it's not suitable for widefield.
>>
>>> It's a nonlinear process and with the same average intensity of
>>>
>> illumination the signal will be the higher the higher is the peak
>> intensity. To get intense peak illumination you can focus it spatially (to
>> a diffraction-limited spot) or 'temporally' (with fs pulses); one has to
>> use both approaches to get appreciable results with common fluorescent
>> dyes...
>>
>>> Shortening the pulses is vital, but you cannot go to 1fs - the spectrum
>>>
>> would be too broad. I don't think the microlenses could stretch the pulses,
>> because they are fairly thin. The do destroy the wavefronts a bit (coz the
>> are so small...), but this is cleaned up by the pinholes...
>>
>>> Simply put, in a regular confocal you are creating one
>>>
>> diffraction-limited spot, in a spinning disc you work with thousand spots.
>> So you would need thousand times more power (assuming the same pulse
>> duration). Bu then the thermal effects (assuming the contribution of the
>> multiphoton processes is negligible) also increase thousand times...
>>
>>> And now the solutions:
>>> 1) use less pinholes - you hardly can modify your disc, so you decrease
>>>
>> FOV instead, like in that paper.
>>
>>> 2) use better dyes - there are special up-conversion dyes that work even
>>>
>> in widefield and without femtoseconds, so some could be found that would
>> work here.
>>
>>> 3) more powerful pulses - not necessarily shorter, if I got the money I
>>>
>> would find someone to build a pulse picker and an amplifier for me. I think
>> 80 kHz repetition with thousand times the peak power could work and the
>> scanning artifacts wouldn't be too severe (you may imagine this can't work
>> with regular confocal...)
>>
>>> Sorry for the lengthy post, bu I didn't want to disclose my brightest
>>>
>> ideas on the first few lines :-).
>>
>>> Cheers,
>>>
>>> zdenek
>>>
>>> ---------- Původní zpráva ----------
>>> Od: Unruh, Jay
>>> Datum: 15. 2. 2013
>>> Předmět: Re: multiphoton spinning disc
>>>
>>> I would imagine that quite a bit could be gained by going to a shorter
>>>
>> pulsed laser and performing dispersion compensation. I would guess that
>> the micro lens array introduces a significant amount of dispersion. Of
>> course many of the shorter pulsed lasers aren't tunable either. Large
>> field of view applications with longer pulsed lasers may result in an
>> undesired amount of heating anyway. Del Mar ventures (no commercial
>> interest) actually sells a DIY kit for a<20 fs laser for much less than a
>> single box tunable system.
>>
>>> Jay
>>>
>>> -----Original Message-----
>>> From: Confocal Microscopy List [mailto:[log in to unmask]]
>>>
>> On Behalf Of Craig Brideau
>>
>>> Sent: Friday, February 15, 2013 11:46 AM
>>> To: [log in to unmask]
>>> Subject: Re: multiphoton spinning disc
>>>
>>> *****
>>> To join, leave or search the confocal microscopy listserv, go to:
>>> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
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>>>
>>> If you could sacrifice tunability, fiber lasers are pretty much there,
>>>
>> at least for 1040nm. Time-bandwidth-products (the company, not the unit of
>> merit for pulsed lasers) makes a death ray called the Fortis that outputs
>> 50W at 50 MHz...
>>
>>> Craig
>>>
>>>
>>> On Fri, Feb 15, 2013 at 9:37 AM, Tim Feinstein wrote:
>>>
>>>
>>>
>>>> *****
>>>> To join, leave or search the confocal microscopy listserv, go to:
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>>>>
>>>> Hello all,
>>>>
>>>> There is an interesting demonstration of multiphoton spinning disc
>>>> confocal imaging in the latest PNAS by Yuko Mimori-Kosue from RIKEN.
>>>> It shows the expected Z-resolution, depth and s/n improvements (maybe
>>>> a little better than due to pinhole refinement), but their last
>>>>
>> paragraph is a doozy.
>>
>>>> "In putting the system to practical use, the available output laser
>>>> power is the limiting factor for the illumination area and the maximum
>>>> imaging depth. Even with the two-photon lasers having the highest
>>>> levels of output power currently available, we could trigger
>>>> two-photon absorption for only ∼40-μm-diameter areas of GFP-expressing
>>>> animals (less than 10% of the effective frame size with a 60×
>>>> objective; Fig. S1B). Lasers with roughly
>>>> 5–10 times the power would be required. The higher laser power is also
>>>> required to excite red fluorescent proteins, which can be excited at
>>>> wavelengths between 1,000 and 1,200 nm, at which the output power of
>>>> the existing mode-locked laser decreases to ∼15% of peak power. "
>>>>
>>>> Is there any chance of seeing a ti-sapphire with 5 to 10-fold more
>>>>
>> power?
>>
>>>> Would it cost 5-10 times as much? It sounds like a nice approach but
>>>> maybe not so much if you need a military LASER to use it. On the
>>>> other hand maybe resonant two-photon (or slit-scanning, with
>>>> sacrifices) can already deliver similar performance. Thoughts
>>>>
>> appreciated.
>>
>>>> All the best,
>>>>
>>>>
>>>> TF
>>>>
>>>> Timothy Feinstein, PhD
>>>> Visiting Research Associate
>>>> Laboratory for GPCR Biology
>>>> Dept. of Pharmacology& Chemical Biology University of Pittsburgh,
>>>> School of Medicine BST W1301, 200 Lothrop St.
>>>> Pittsburgh, PA 15261
>>>>
>>>>
>>>>
>>
>
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