The ability to control the spatial shape of light in non linear light-matter interaction has the advantage of frequency conversion aside the spatial shaping, enabling a compact manner of producing light at a desired frequency and shape.  

We show results[1] of on-axis second-harmonic generation (SHG) of arbitrary shaped beams, with complete control of both the amplitude and phase pattern in one transverse axis. Our high resolution fabrication enabled us to generate interesting one dimensional shapes, from different Hermite-Gauss and Top-Hat beams to arbitrary skyline functions such as the Taj-Mahal and Empire State building. On axis holograms are much more efficient than previously demonstrated[2] Fourier holograms (where the desired beam shape is revealed off-axis in diffraction orders in the far field) and are especially fitting for the non linear process since the separation of the desired image from the reference beam can be achieved by spectral filtering.

 In order to extend our control of the SH light beam, the shaping of the SH trajectory has also been explored. While previous research[3] showed the generation of “self-accelerating” beams – self similar beams which follow a certain fixed curved trajectory, we show preliminary results of the shaping of the SH light beam generated in a non linear crystal where the beam follows an arbitrary caustic trajectory after the crystal. We show different polynomial trajectories, as well as bottle beams and temperature-controlled trajectories (where a change in the crystal temperature changes the direction of the light’s trajectory.

  [1] S. Trajtenberg-Mills, I. Juwiler, and A. Arie, “On-axis shaping of second-harmonic beams,” Laser Photon. Rev.,  DOI: 10.1002/lpor.201500154, Sep. 2015.

[2] A. Shapira, I. Juwiler, and A. Arie, “Nonlinear computer-generated holograms.,” Opt. Lett., vol. 36, no. 15, pp. 3015–7, Aug. 2011.

[3] T. Ellenbogen, N. Voloch-Bloch, A. Ganany-Padowicz, and A. Arie, “Nonlinear generation and manipulation of Airy beams,” Nat. Photonics, vol. 3, no. 7, pp. 395–398, Jun. 2009.