Pupil filters are widely used to improve the resolution of confocal microscopes. We analyze the possibilities of applying them to N-photon microscopy. We find that taking a linear combination of images obtained with several pupil filters can improve the resolution by a factor of N (compared to a conventional microscope). When applied to saturable fluorescence, this technique allows one to observe fluorescent objects with, in principle, unlimited spatial resolution.
© 2009 Optical Society of America
Original Manuscript: September 16, 2008
Revised Manuscript: November 21, 2008
Manuscript Accepted: December 8, 2008
Published: February 10, 2009
Vol. 4, Iss. 4 Virtual Journal for Biomedical Optics
Osip Schwartz and Dan Oron, "Using variable pupil filters to optimize the resolution in multiphoton and saturable fluorescence confocal microscopy," Opt. Lett. 34, 464-466 (2009)