Nonlinear optical processes in waveguides play important roles in compact integrated photonics, while efficient coupling and manipulations inside the waveguides still remain challenging. In this work, we propose a new scheme for second-harmonic generation as well as beam shaping in lithium niobate slab waveguides with the assistance of well-designed grating metasurfaces at λ=1064 nm. By encoding the amplitude and phase into the holographic gratings, we further demonstrate strong functionalities of nonlinear beam shaping by the metasurface design, including dual focusing and Airy beam generation. Our approach would inspire new designs in the miniaturization and integration of compact multifunctional nonlinear light sources on chip.

中文翻译：

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通过光栅超表面在铌酸锂平板波导中产生和操纵二次谐波

波导中的非线性光学过程在紧凑型集成光子学中发挥着重要作用，而波导内部的有效耦合和操纵仍然具有挑战性。在这项工作中，我们在精心设计的 λ=1064 nm 光栅超表面的帮助下，提出了一种新的二次谐波产生方案以及铌酸锂板条波导中的光束整形方案。通过将振幅和相位编码到全息光栅中，我们进一步展示了超表面设计的非线性光束整形的强大功能，包括双聚焦和艾里光束生成。我们的方法将激发芯片上紧凑型多功能非线性光源小型化和集成的新设计。