TY - JOUR
T1 - Subwavelength anti-diffracting beams propagating over more than 1,000 Rayleigh lengths
AU - DelRe, Eugenio
AU - Di Mei, Fabrizio
AU - Parravicini, Jacopo
AU - Parravicini, Gianbattista
AU - Agranat, Aharon J.
AU - Conti, Claudio
N1 - Publisher Copyright:
© 2015 Macmillan Publishers Limited. All rights reserved.
PY - 2015/3/31
Y1 - 2015/3/31
N2 - Propagating light beams with widths down to and below the optical wavelength require bulky large-aperture lenses and remain focused only for micrometric distances. Here, we report the observation of light beams that violate this localization/depth-of-focus law by shrinking as they propagate, allowing resolution to be maintained and increased over macroscopic propagation lengths. In nanodisordered ferroelectrics we observe a non-paraxial propagation of a sub-micrometre-sized beam for over 1,000 diffraction lengths, the narrowest visible beam reported to date. This unprecedented effect is caused by the nonlinear response of a dipolar glass, which transforms the leading optical wave equation into a Klein-Gordon-type equation that describes a massive particle field. Our findings open the way to high-resolution optics over large depths of focus, and a route to merging bulk optics into nanodevices.
AB - Propagating light beams with widths down to and below the optical wavelength require bulky large-aperture lenses and remain focused only for micrometric distances. Here, we report the observation of light beams that violate this localization/depth-of-focus law by shrinking as they propagate, allowing resolution to be maintained and increased over macroscopic propagation lengths. In nanodisordered ferroelectrics we observe a non-paraxial propagation of a sub-micrometre-sized beam for over 1,000 diffraction lengths, the narrowest visible beam reported to date. This unprecedented effect is caused by the nonlinear response of a dipolar glass, which transforms the leading optical wave equation into a Klein-Gordon-type equation that describes a massive particle field. Our findings open the way to high-resolution optics over large depths of focus, and a route to merging bulk optics into nanodevices.
UR - http://www.scopus.com/inward/record.url?scp=84926333767&partnerID=8YFLogxK
U2 - 10.1038/nphoton.2015.21
DO - 10.1038/nphoton.2015.21
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AN - SCOPUS:84926333767
SN - 1749-4885
VL - 9
SP - 228
EP - 232
JO - Nature Photonics
JF - Nature Photonics
IS - 4
ER -