Friends
I think that everything is really simpler. Removing the crystal is a
simple operation and re-alignement as well.
I agree that fs is not always better than ps, this can depend on your
own need.
We performed imaging both using ps and fs. I do not have any strange
patent issue, I simply try to make research. I fully understand all
the patent issues and I do respect them, even if I continue thinking
that the TPE patent blocked research in the field for some years with
exceptions. It is well now that ALL microscopy companies can provide
systems that can be adapted for multiphoton imaging including SHG
etc... It is also very well known that in some cases there is the need
for special techniques but people managing the microscopy lab do not
have resources or time that can be devoted to users, bright users,
that do not want to be active part of the image formation process
having their own research plan. I think that any attempt of perfoming
microscopy imaging has to be helped and favoured, when possible.
This list is a great source of help, so please, make your experimental
designs without thinking about patents, ask your questions...get the
answers...not always you can get the right one but everything can help
growth ...
All the best
Alby
On Oct 13, 2009, at 5:26 PM, Craig Brideau wrote:
> You must have some strange patent issues. I am not a lawyer, so take
> what I say with a grain of salt, however it seems that as long as it
> is for use in your own lab and you are not selling a product involving
> fs lasers or otherwise profiting then you should be within your rights
> to simply remove the stretcher block from your system.
>
> Craig
>
>
> On Tue, Oct 13, 2009 at 7:26 AM, Evangelos <[log in to unmask]
> > wrote:
>> Femto is not always necessarily better. You can safely use more
>> average power with picosecond compared to femtosecond to go deep
>> into brain
>> or muscle tissue. I have found that picosecond is /sometimes/
>> better than
>> femtosecond, even for SHG. Femtosecond will give more initial
>> signal but
>> picosecond signal will stay constant, longer, at the same power, in
>> tissue.
>> Also, for our confocal core's speciality: CARS microscopy,
>> picosecond is
>> far superior in that it matches the vibrational linewidths and
>> doesn't dump
>> a lot of energy in a broad spectral region like femtosecond pulses.
>> Dispersion is far less of a problem with pico and not as much need
>> to
>> pre-comp, but I do believe for THG, and if you have very weak 2-
>> photon
>> signal you would have to used pre-chirped compressed femtosecond
>> pulses,
>> with SHG on collagen, 2-photon with more average power, and CARS
>> you're ok
>> with pico, otherwise you need femto.
>>
>> Best,
>> Evangelos
>>
>> Advanced Biological Imaging Scientist
>> Harvard Center for Nanoscale Systems
>> 11 Oxford Street
>> Cambridge, MA 02138
>>
>> Manja Schubert wrote:
>>>
>>> Dear Confocal list members,
>>>
>>> I have a question to multiphoton technology - femto second IR
>>> laser versus
>>> pico second IR laser.
>>> We run in following problem. We have a femto second laser but
>>> because of
>>> patent law we can use it only with attenuation filter and a pulse
>>> stretcher
>>> meaning in the end we scanning with a pico second IR laser.
>>>
>>> Has anyone experienced how that effect the scanning outcome? For
>>> example,
>>> the possible deepness of the scan. Any thoughts are highly
>>> appreciated.
>>>
>>> Many thanks in advance!
>>>
>>> Cheers,
>>> Manja
>>>
>>> Dr. Manja Schubert
>>> University of Bergen
>>> Department of Biomedicine
>>> Jonas Lies vei 91
>>> 5009 Bergen
>>> Norway
>>> Tel:+47-55 58 67 15
>>
----------------------------------------
Alberto Diaspro
Head, Nanophysics Unit
Senior Scientist
The Italian Institute of Technology -IIT
Via Morego, 30
16163 - Genova (Italy)
phone: +39 010 71781503
mobile: +393666719968
fax: +39 010 720321
http://www.iit.it
[log in to unmask]
Professor of Applied Physics
Department of Physics
University of Genova
Via Dodecaneso, 33
16146 Genova - Italy
tel. +39 010 353 6426
fax. +39 010 314218
http://www.lambs.it
[log in to unmask]
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