"Optical Airy beams and bullets"

In recent years, the quest for non-spreading or non-diffracting optical beam configurations has

been motivated by possible  applications in diverse fields ranging from biology to atom optics.

Lately our group has explored the possibility of experimentally realizing non-spreading

accelerating Airy beams in optics. This was done by exploiting the formal analogy between

quantum wave mechanics and paraxial diffraction optics. We have demonstrated, that even

though they are exponentially truncated (thus conveying finite energy), these Airy beams still

exhibit a host of interesting characteristics. More specifically, they resist diffraction while their

main intensity maxima or lobes tend to self-bend and accelerate in free space along parabolic

trajectories. This ballistic behavior persists over long distances in spite of the fact that the center

of gravity of these wavepackets remains constant  (in agreement with Ehrenfest’s  theorem)  and

eventually diffraction takes over. Figure (a) depicts quasi-diffractionless propagation of a finite-

energy Airy beam where its “acceleration” dynamics are apparent. These intriguing properties of

the Airy wavepackets put them in a category by themselves. These beams, in contrast to the

already known families of non-diffracting fields; are possible in one-dimension (excellent

candidates for time applications), do not result from conical superposition, and  are thus  highly

asymmetric. The peculiar features of Airy beams may find applications in near-field microscopy

where their asymmetric intensity pattern could prove advantageous. Particle sorting (via optical

gradient forces) along bent parabolic trajectories may be another fascinating direction.

Here we provide an overview of our recent work on optical Airy beams and bullets. Other

aspects like their self-healing properties or the possibility of generating for the first time spatio-

temporal optical Airy bullets (b) will be also discussed.