Re: Uniformity of 2-photon illumination?

Posted by Craig Brideau on
URL: http://confocal-microscopy-list.275.s1.nabble.com/Uniformity-of-2-photon-illumination-tp6719119p6726443.html

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Just set your power control up as close to your laser as possible.  I use a
1/2 waveplate and polarizing splitter cube with a sturdy metal beam dump.
 That way any beam from that point onward is at most a few hundred mW, and
for most imaging applications 200mW or less is plenty.  I also keep a few
movable beam blocks handy at all times.  If I need to work with the laser, I
throw multiple blocks into the system, then remove them as I go.  That way
the laser is never going further than the next block in the system.  Here is
my blocking 'recipe':

For the actual blocks, I use Thorlabs blank cage plates (CP02)
http://www.thorlabs.com/thorProduct.cfm?partNumber=CP01
These can handle the full brunt of a Ti:Saph if necessary, and the
black anodizing tends to absorb the beam nicely.

I put the CP02 on a standard post TR3
http://www.thorlabs.com/thorProduct.cfm?partNumber=TR3

I put the post in a magnetic post holder PH3E
http://www.thorlabs.com/thorProduct.cfm?partNumber=PH3E

I usually use them in pairs; one blocks the laser a bit further down the
table, while the other I keep up close.  The magnetic holder allows you to
easily move and reposition them.  By using multiple blocks, I ensure there
is always at least one somewhere in the beam.  I only remove the last one
when I am ready to shoot the beam into the microscope.  The only caution I
have is the TR3 post is shiny stainless, so always move the blocks sideways
out of the beam rather than lifting them straight up. (you can paint the
exposed portion of them black if it is an issue) If you get PH4 holders you
can drop the post completely into the post holder, but this limits your
ability to move the block up and down.  Collar R2 can help cover up the post
and be used to lock it to a specific height:

http://www.thorlabs.com/thorProduct.cfm?partNumber=R2

Hope this helps!

Craig


On Thu, Aug 25, 2011 at 9:36 AM, Armstrong, Brian <[hidden email]>wrote:

> Hi Stuart, in short, I align the 2P beam just as described by Julio in
> previous e-mail reply. I suggest you call your Zeiss service rep and then
> watch how he aligns the 2P to the vis laser(s). Once you've seen it, the
> protocol should be very easy to replicate.
> You may already have a saved configuration called "2P Align" in
> C:AIM/settings that you can use. Also, you should have received a mirror
> slide with a grid on it that is perfect for this kind of alignment.
>
> Adjusting the beam path as Julio described is quite easy to do.
> Also, don't look into the laser light with your remaining good eye (first
> heard this sound advice from George McNamara).
>
> Cheers,
>
> Brian D Armstrong PhD
> Assistant Research Professor
> Light Microscopy Core
> Beckman Research Institute
> City of Hope
> Dept of Neuroscience
> 1450 E Duarte Rd
> Duarte, CA 91010
> 626-256-4673 x62872
>
>
> http://www.cityofhope.org/research/support/Light-Microscopy-Digital-Imaging/Pages/default.aspx
>
>
> -----Original Message-----
> From: Confocal Microscopy List [mailto:[hidden email]]
> On Behalf Of stu_the_flat
> Sent: Thursday, August 25, 2011 3:38 AM
> To: [hidden email]
> Subject: Re: Uniformity of 2-photon illumination?
>
> *****
> To join, leave or search the confocal microscopy listserv, go to:
> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
> *****
>
> Thank you very much for your replies.
>
>
>
> Just to clear up a few points, I always
> take Z sections of the slide just to make sure it wasn’t a case that the
> slide
> was at an angle, (The system is not designed to hold slides so its always a
> bit
> “Heath Robison” trying to get a slide underneath it!)
>
>
>
> I had checked various sites around the
> slide and I was getting consistent results, yesterday I scanned the slide
> with
> the descanned detectors and got a similar image.
>
>
>
> We want all the power we can get as would
> love to be able to image more deeply into cardiac muscle, (is it a fair
> assumption that more power will allow us to image deeper?) for that reason
> we
> have a Coherent Chameleon Ultra II, and I believe its peak power is around
> 5.5W. However would the alignment not take place “down stream” of the OPO?
> So I
> could just set that to its minimum intensity setting.
>
>
>
> Anyway it is kind of irrelevant because the
> system is under service contract with Zeiss, So all I need to do it get on
> the
> phone and start whining at them, Although I would love to give laser
> alignment a
> go myself!
>
>
>
> Once again thank you for all your replies
>
>
>
> Yours
>
> Stuart McIntyre
>
>
>
> --
> View this message in context:
> http://confocal-microscopy-list.588098.n2.nabble.com/Uniformity-of-2-photon-illumination-tp6719119p6723940.html
> Sent from the Confocal Microscopy List mailing list archive at Nabble.com.
>
>
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