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Tube lens, or scan lens?

Craig


On Mon, Jan 17, 2011 at 3:06 PM, Andreas Bruckbauer <[log in to unmask]>wrote:

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>
> I guess the initial question about chromatic aberration and the new one
> about TIRF got muddeled up. I guess chromatically different NA in TIRF could
> arise when part of the correction is build in the tube lens? The
> illumination light forTIRF "through the objective" does not pass the tube
> lens and is thus is not well corrected. Furthermore slight imperfections in
> the dichroic which relfects the laser light can lead to distortions and
> these can be wavelength dependent.
>
>
> best wishes
>
> Andreas
>
>
>
> -----Original Message-----
> From: Craig Brideau <[log in to unmask]>
> To: [log in to unmask]
> Sent: Mon, 17 Jan 2011 19:01
> Subject: Re: Objective lens chromatic aberration
>
>
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>
>
> This would also lead to chromatically dependent NA, which would be a big
>
> no-no for a corrected objective.
>
>
>
> Craig
>
>
>
>
>
> On Sun, Jan 16, 2011 at 2:16 PM, Mark Cannell <[log in to unmask]
> >wrote:
>
>
>
> > *****
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> > To join, leave or search the confocal microscopy listserv, go to:
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> > http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
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> > *****
>
> >
>
> > I suggest it is much more likely that the fiber/rear aperture coupling
> lens
>
> > was at fault.  I must admit I don't see how with rear aperture
> illumination
>
> > the same and same focal length for the 3 lasers  how the incident rays
> could
>
> > have different angles ...
>
> >
>
> > Cheers
>
> >
>
> >
>
> >
>
> >  *****
>
> >> To join, leave or search the confocal microscopy listserv, go to:
>
> >> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
>
> >> *****
>
> >>
>
> >> Hi Michael,
>
> >>
>
> >> There are a few factors that need to be compromised in TIRF.   1) The
> TIRF
>
> >> penetration depth is dependent upon the wavelength of the incident
>
> >> illumination, the angle of incidence, and the refractive indices of the
>
> >> media at the interface. 2) An apochromatic lens brings lasers of three
>
> >> wavelengths on to the same focal plane, but may not to the same incident
>
> >> angle.  Therefore, the incident angles for the three lasers should be
> able
>
> >> to be adjusted independently to get optimal TIRF images.
>
> >>
>
> >> You may want to take your sample off first, to see how different the
>
> >> angles
>
> >> of the three lasers projecting to the wall, to get an idea of the
> incident
>
> >> angles of your lasers coming out of the objective.
>
> >>
>
> >> Regards
>
> >>
>
> >> Gary G Li, PhD
>
> >>
>
> >>
>
> >> On Sun, Jan 16, 2011 at 1:02 PM, Cammer, Michael <
>
> >> [log in to unmask]
>
> >>
>
> >>> wrote:
>
> >>>
>
> >>
>
> >>  *****
>
> >>> To join, leave or search the confocal microscopy listserv, go to:
>
> >>> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
>
> >>> *****
>
> >>>
>
> >>> I originally posted the message below to the microscopy listserv but
>
> >>> reviewing the discussion here on chromatic aberration, I thought it
> would
>
> >>> be
>
> >>> apropos here too even though it is not really regarding confocal.
>
> >>>
>
> >>> A few years ago we were having problems with the first commercial
> Olympus
>
> >>> TIRF system because we could not get consistent evanescent waves with
> the
>
> >>> one angle adjustment with the laser lines we had from 405 to 568 nm
> that
>
> >>> were delivered via a single fiber (it was worse when we later added a
> 633
>
> >>> nm
>
> >>> laser).  I suggested we pump each laser in through a separate path that
>
> >>> could be angled independently.  We didn't build it, but I think Olympus
>
> >>> now
>
> >>> sells a TIRF system that does this.
>
> >>>
>
> >>> Another issue is that when I first heard about TIRF maybe 15 years ago,
>
> >>> it
>
> >>> was introduced as a ring illumination at the outer edge of the back
>
> >>> aperture, not as a single point or crescent at the periphery on only
> one
>
> >>> side.  A ring, or at least a series of points around the periphery,
> seems
>
> >>> like a better way to provide a uniform field due to aberrations from
>
> >>> coherent light in the imperfect optics.  Any thought on this?
>
> >>>
>
> >>> Sincerely,
>
> >>>
>
> >>> Michael
>
> >>>
>
> >>> -----------------------ORIGINAL MESSAGE-------------------------------
>
> >>> We have the Nikon TIRF system and have three laser lines
>
> >>> going into the TIRF arm via a single fiber.  When we project through
>
> >>> the 100X objective through the sample onto the wall we see that the
>
> >>> lines go through the sample at different angles.  (You can see a
>
> >>> picture of the projection at approx 45 degrees at
>
> >>> http://www.flickr.com/photos/mcammer/5359189090/ .)  It is also
>
> >>> noticeable in the TIRF images that the field depth is different for
>
> >>> each wavelength.  Is this unavoidable due to the different
>
> >>> wavelengths or is it possible to align the optics better so these
>
> >>> spots would be more coincident?
>
> >>>
>
> >>>
>
> >>>
>
> >>> _________________________________________
>
> >>> Michael Cammer, Assistant Research Scientist
>
> >>> Skirball Institute of Biomolecular Medicine
>
> >>> Lab: (212) 263-3208  Cell: (914) 309-3270
>
> >>>
>
> >>>
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