2023/11/22 by Zihua Zheng, Zheng, Zihua, Ziwen Tang +5
Engineering · Materials Science · Physics and Astronomy · #FOS: Physical sciences #Nonlinear Optical Materials Research #Optics (physics.optics) #Photonic and Optical Devices #Photorefractive and Nonlinear Optics
paper · pdf · doi:10.48550/arxiv.2311.13426
openalex publication_date 2023/11/22 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
In this paper, the optimal solution of effective nonlinear coefficient of quasi-phase-matching (QPM) crystals for coupled third harmonic generation (CTHG) was numerically investigated. The effective nonlinear coefficient of CTHG was converted to an Ising model for optimizing domain length distributions of aperiodically poled lithium niobate (APPLN) crystals with lengths as 0.5 mm and 1 mm, and fundamental wavelengths ranging from 1000 nm to 6000 nm. A method for reconstructing crystal domain poling weight curve of coupled nonlinear processes was also proposed, which demonstrated the optimal conversion ratio between two coupled nonlinear processes at each place along the crystal. In addition, by applying the semidefinite programming, the upper bound on the effective nonlinear coefficients deff for different fundamental wavelengths were calculated. The research can be extended to any coupled dual \chi(2) process and will help us to understand better the dynamics of coupled nonlinear interactions based on QPM crystals.