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Dear all,
I'm currently working on the design and fabrication of a cheap compact confocal microscope and I have a question regarding the design of the scanning system. For practical reasons, the ideal solution for me would be to keep the sample stationary and scan the laser beam focus in the XYZ directions.
After looking through the literature, I was thinking to use the standard design consisting of  2 closely spaced galvo mirrors for the XY scan , and move the objective in the axial direction for the Z stacks. However I am not sure whether these 2 approaches are compatible; from what I read it seems this is the case but there is a point that confuses me.
Indeed, the proper positioning of the galvo mirrors requires that their pivot point is imaged on the back focal (telecentric) plane of the objective via a scan lens and tube lens, meaning that the distance between the mirrors and the back focal plane of the objective must remain fixed. On the other hand, if I move the objective (independently) to adapt the Z-position of the focus, it would mean that the mirror-objective distance is changed...
I hope my question makes sense and I'd really grateful for any help.
Many thanks,
José

José DINTINGER
Research scientist
BioMEMS Section
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