Airy optical beams, representing an intriguing class of wave packets (initially predicted by Berry and Balazs in 1979), can exhibit unusual features such as the ability to remain diffraction-free over long distances while they tend to freely accelerate during propagation. The Airy beam is asymmetric, with one bright region at the center and a series of progressively dimmer patches on one side of the central spot. But rather than propagating in a straight line, the entire pattern of bright and dark patches curves toward one side. At the same time, the width and intensity of each patch remains essentially constant, even after an ordinary beam would have dropped to nearly half its original intensity and spread to several times its original width.
April 16, 2012 [Monday] @ 12:00: Professor Ady Arie (Tel Aviv University) will give a talk on "Beam Shaping and Control Using Nonlinear Photonic Crystals".
Abstract: By modulating the quadratic nonlinear coefficient of ferroelectric crystals, it is possible to simultaneously convert the input frequency into one of its harmonics and at the same time to change the shape of the generated beam. I will discuss two methods for nonlinear beam shaping, based on transverse phase offset and on nonlinear realization of a computer generated hologram. These methods are used to nonlinearly generate and manipulate accelerating Airy beams, parabolic beams and vortex beams, as well as to convert Hermite Gaussian beam at the fundamental frequency to high order Hermite Gaussian beams at the second harmonic.
Place: Holon Institute of Technology, Faculty of Sciences, Seminar Room 308/8 [unusual venue]