Spatial dispersion control with Laue-geometry photonic crystals

We propose and experimentally demonstrate an integrated approach to suppress Kerr self-focusing by engineering the spatial dispersion of a medium using photonic crystals of Laue geometry (Laue-type PhC). The PhC, featuring longitudinally chirped and constant-period sections, was designed using a beam-propagation model and fabricated within a UV-fused silica substrate via femtosecond direct laser writing with a Bessel beam. We characterized the structure by performing nonlinear transmission measurements and analyzing the output beam profile evolution as a function of input pulse energy. Compared to a non-resonant reference structure and the bulk material, the dispersion-engineered PhC successfully counteracts self-focusing, resulting in a 12% increase in the nonlinear absorption threshold. This work presents the first practical demonstration of nonlinearity management through spatial dispersion control in a monolithic PhC, offering a new pathway to bypass the power-scaling limitations of nonlinear processes in solid-state materials.