Fig. 5: SAAL-based multi-functional nonlinear light modulation in quartz crystal.
a Schematic diagram of multi-functional nonlinear beam shaping using SAAL-produced photonic architectures. b Phase-matching principle for simultaneous generation of SH and TH vortex light beams by constructing multi-layer fork-shaped gratings. kω, k2ω, and k3ω are the wavevectors of the fundamental, SH, and TH waves, respectively. G1 and G2 are reciprocal vectors. Λ1 and Λ2 are periods of the multi-layer gratings. c SHG power and efficiency as a function of fundamental power and layer number. Inset: spectrum of the SH beam. d THG power and efficiency as a function of fundamental power at a layer number of 15 (detailed structure design see “Methods”). Inset: spectrum of the TH beam. e Schematic diagram of periodically inverted cascaded fork-shaped gratings that can make the SH and the TH vortex beams with opposite topological charges interfere with each other, respectively. f Experimentally generated complex nonlinear light fields using the design presented in (e). g Design (left) and fabrication (middle) of a compound nonlinear grating with more complex interior structures and the SH vortex arrays (right) generated by the fabricated structure. Scale bar: 50 μm
