Improved imaging for second harmonic generation via a two-dimensional quasi-multivalue-encoding method

Computer generated holography has attracted great interest in nonlinear wavefront shaping or imaging. Due to the fabrication limitations of the nonlinear crystal structure, the classical binary encoding method is adopted in most nonlinear wavefront shaping, which has obvious shortcomings in imaging efficiency and quality. An improved two-dimensional quasi-multivalue-encoding method is proposed to construct high-efficiency and highquality nonlinear manipulation. Theoretical and experimental results indicate that the two-dimensional quasimultivalued encoding method generates images more delicately and decreases diffraction compared to classical binary encoding method. This modified approach offers broad applications in the fields of polarization control, information storage, and nonlinear manipulation.