Subwavelength anti-diffracting beams propagating over more than 1,000 Rayleigh lengths

Eugenio DelRe, Fabrizio Di Mei, Jacopo Parravicini, Gianbattista Parravicini, Aharon J. Agranat, Claudio Conti

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61 Scopus citations


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.

Original languageAmerican English
Pages (from-to)228-232
Number of pages5
JournalNature Photonics
Issue number4
StatePublished - 31 Mar 2015

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