Nonlinear computer-generated holograms

We propose a novel technique for arbitrary wavefront shaping in quadratic nonlinear crystals by introducing the concept of computer-generated holograms (CGHs) into the nonlinear optical regime. We demonstrate the method experimentally showing a conversion of a fundamental Gaussian beam pump light into the first three Hermite– Gaussian beams at the second harmonic in a stoichiometric lithium tantalate nonlinear crystal, and we characterize its efficiency dependence on the fundamental power and the crystal temperature. Nonlinear CGHs open new possibilities in the fields of nonlinear beam shaping, mode conversion, and beam steering. © 2011 Optical Society of America OCIS codes: 190.2620, 090.2890. Holography is a method for storing and reconstructing the amplitude and phase of a wavefront from an illumi-nated object [1]. Rather than using a real object, it was proposed in 1966 by Brown and Lohmann [2] to compute and print the required pattern of the hologram. When a light beam is sent through a computer-generated holo-gram (CGH), the far-field diffracted wavefront has the de