http://confocal-microscopy-list.275.s1.nabble.com/Re-pre-chirping-what-diagnostics-to-use-tp590162p590170.html
problem. If you have a spectrometer and an autocorrelator, you can
guarantee virtually the same pulse that you had before. For the
> Search the CONFOCAL archive at
>
http://listserv.acsu.buffalo.edu/cgi-bin/wa?S1=confocal>
> Dear Jerry and others,
>
> What diagnostics do you use for tuning of two photon laser or OPO? Is laser
> spectrum analyzer enough?
>
> We have a shared two photon (MIRA 900F Femtosecond configuration) and OPO
> from Coherent. One of the main user is very afraid of tuning it - so he
> always has a service engineer tune it to 830nm and longest possible pulse
> (since he does spectroscopy). There are two more of us who will benefit by
> tuning it for two-photon and SHG (different wavelengths and shortest
> possible pulse).
> How is the 'reproducibility' of laser beam profile when working with these
> lasers? One of the main concern that other user has is that - if you cannot
> come back to exactly 830 nm after tuning to say 740 nm, the custom optical
> setup will go out of alignment.
>
> Thanks
> Regards
> Shalin
>
>
>
> On 8/30/07, Mark Cannell <
[hidden email]> wrote:
>>
>> Search the CONFOCAL archive at
>>
http://listserv.acsu.buffalo.edu/cgi-bin/wa?S1=confocal>>
>> Hi Gerry
>>
>> The typical path using 2 prisms is via a small mirror into the first
>> prism (we set this at minimum at minimum deviation but this can be
>> changed to alter chirp). Then to the second prism (at minimum devation
>> to produce a collimated horizontally spread spectrum), and then two
>> mirrors to reflect the light back and displace the beam vertically which
>> then passes back through the second and first prisms respectively. After
>> the beam has left the first prism, note the beam has been displaced
>> vertically is and thereby separated from the input beam.
>>
>> BUT are you sure you need to do this? If the input pulse is ~120 fs the
>> pulse broadening is quite minor. We used a pair of gold mirrors to to
>> return and displace the beam but if you have 1" fs mirrors they would
>> work as well.
>>
>> For typical prism spacing see:
>>
>> Soeller, C. & Cannell, M.B. (1996) Construction of a two-photon
>> microscope and optimisation of illumination pulse width. _Pflugers
>> Archiv_ 432: 555-561.
>>
>> Cheers Mark
>>
>> Jerry Sedgewick wrote:
>>> Search the CONFOCAL archive at
>>>
http://listserv.acsu.buffalo.edu/cgi-bin/wa?S1=confocal>>>
>>> I am interested in setting up pre-chirping in the laser path going to
>>> a custom built multiphoton. I have been searching in vain for exact
>>> information on the components. I bought the prisms, but I am uncertain
>>> about the first mirror that directs the laser to the prisms (and then
>>> allows the returning, reflected laser to pass through), and the second
>>> mirror. My guess is that the first mirror must be a linear polarizer,
>>> or a polarizer that separates the s and p polarization. The second
>>> mirror must be a grating of some sort that re-polarizes the laser so
>>> that it passes through the first mirror.
>>>
>>> Rather than guessing, it would make my day if I could get specifics on
>>> the mirrors.
>>>
>>> Thanks!
>>>
>>> Jerry Sedgewick
>>
>
>
>
>
Dept. of Chemical Sciences