Nonlinear Volume Holography in 3D Nonlinear Photonic Crystals

Nonlinear photonic crystals (NPCs) are transparent materials with a space-dependent (often periodic) second-order nonlinearity, which have been used extensively for the generation and control of coherent light at new frequencies. Thanks to recently introduced fabrication techniques capable of 3D nonlinearity engineering, explorations of nonlinear wave interaction with improved or unique functionalities of 3D configurations become possible. Here, the experimental example of nonlinear volume holography based on 3D NPCs is presented. The 3D modulation of nonlinearity enables reconstruction of optical beams at new frequency with predesigned phase and amplitude structures. Furthermore, a simultaneous synchronization of phase velocities of the fundamental reading beam and the generated new frequency beam ensures increased conversion efficiency. A proof-of-concept nonlinear holographic reconstruction of second harmonic vortex beam is obtained with an optically induced 3D nonlinear volume hologram in ferroelectric calcium barium niobate crystal. The results show the nonlinear volume holography based on 3D NPC provides a novel promising approach for efficient realization of optical complex beams at new frequencies, paving the way for applications in all-optical signal processing, super-resolution imaging, and 3D laser displays.