Nonlinear photonic quasi-periodic spiral

The design of nonlinear photonic Vogel's spiral based on quasi-crystal theory was demonstrated. Two main parameters of Vogel's spiral were arranged to obtain multi-reciprocal circles. Typical structure was fabricated by the near-infrared femtosecond laser poling technique, forming a nonlinear photonic structure, and multiple ring-like nonlinear Raman-Nath second-harmonic generation processes were realized and analyzed in detail. The structure for the cascaded thirdharmonic generation process was predicted. The results could help deepen the understanding of Vogel's spiral and quasi-crystal and pave the way for the combination of quasi-crystal theory with more aperiodic structures. femtosecond laser poling.