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Hello All,

We have an alignment problem.  Our setup, briefly, consists of an 
inverted Nikon TE2000U base, fitted with a Prior stage and a Jena 
piezo (fitted into the Prior).  On the "front" port of the Nikon 
base, we have a CCD, and we have mirrors placed in the infinity space 
of the base redirecting excitation/emission to the sample/detectors, 
respectively.

When we focus up and down, using both objective turret and piezo, we 
see a lateral shift of the image (on the order of hundreds of 
microns), first noticed with the CCD, and then confirmed using an APD 
at the end of "a" detection path in back of the microscope.  By using 
these two methods, we have limited the common components to the piezo 
and the objective turret (The APD path consists, loosely, of light 
source-mirror-objective-sample-objective-mirror-APD. The CCD path is 
light source-sample-objective-tube lens-CCD.).

The only thing we can think of, is that both the piezo and the 
objective turret are shifting laterally off the optical axis during 
focus.  The shift is in the same direction using both components.  If 
either or both of the components were simply off-axis, but moving 
truly axially, I would think that would simply yield an aplanar field 
of view.  I can't imagine that/how/why BOTH of these would be 
shifting like this ...

Comments, ideas, solutions?

Thanks in advance, again.

Best,

Gary



Gary Laevsky, Ph.D.
Keck Facility Manager, CenSSIS
Northeastern University
302 Stearns
360 Huntington Ave.
Boston, MA 02115
Office(617) 373 - 2589
Lab(617) 373 - 7756
Fax(617) 373 - 7783

http://www.censsis.neu.edu

http://www.ece.neu.edu/groups/osl

http://www.keck3dfm.neu.edu