At Twelve Orals of
Matter Scientists
Next meeting
November 20th, 2014 at 14:00
in room S, Physics Dpt
Michele Gintoli
Dipartimento di Fisica e Astronomia "G. Galilei
Università degli Studi di Padova
Vortex phase masks for
structured light generation in
superresolution imaging systems
Abstract:
The use of optical elements able to imprint a vortex pattern to the phase distribution of a light
beam has brought to us the possibility to overcome the resolution limit represented by Abbe’s
criterion.
In astronomy, the vortex coronagraph is able to “peek through” the light of bright stars and
resolve adjacent, weaker secondary sources, thanks to the peculiar filter ability of a doubly
charged vortex phase mask.
In microscopy, single charge vortex phase plates can be used both as filters to achieve
drastic contrast enhancements (spiral phase contrast imaging), or as means to generate
robust “doughnut” beams, indispensable for the now famous STED (STimulated Emission
Depletion) microscopy technique.
STED microscopy, in particular, will be the occasion to experiment with different, more
complex vortex designs, such as combinations of p > 0 Laguerre-Gauss beams.