Scanning microscopy using a short-focal-length Fresnel zone plate.
We demonstrate a form of scanning microscopy using a short-focal-length Fresnel zone plate and a low-NA relay telescope. Owing to a focal length of only 5 microm, the zone plate produces large wavefront tilt and consequently severe vignetting for off-axis illumination. By scanning an optically trapped fluorescent sphere, we measure the vignetted collection region of the zone-plate imaging system. The fluorescence collection efficiency is sharply peaked and has a lateral width of 550 nm, which agrees with numerical simulations.
Schonbrun
Ethan
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School of Engineering and Applied Science, Harvard University, Cambridge, MA 02138, USA. schonbru@seas.harvard.edu
Ye
Winnie N
WN
Crozier
Kenneth B
KB